kopia lustrzana https://github.com/AlexFWulff/awulff-pico-playground
Added initial code
Alex Wulff
commit
d2bd9a7e06
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build/
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cmake_minimum_required(VERSION 3.12)
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include(pico_sdk_import.cmake)
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project(adc_fft_project)
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pico_sdk_init()
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add_executable(adc_fft adc_fft.c)
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add_library(kiss_fftr kiss_fftr.c)
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add_library(kiss_fft kiss_fft.c)
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target_link_libraries(kiss_fftr kiss_fft)
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pico_enable_stdio_usb(adc_fft 1)
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pico_enable_stdio_uart(adc_fft 1)
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pico_add_extra_outputs(adc_fft)
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target_link_libraries(adc_fft
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pico_stdlib
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hardware_adc
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hardware_dma
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kiss_fftr
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)
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/*
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Copyright (c) 2003-2010, Mark Borgerding
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All rights reserved.
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Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
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* Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/* kiss_fft.h
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defines kiss_fft_scalar as either short or a float type
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and defines
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typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */
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#include "kiss_fft.h"
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#include <limits.h>
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#define MAXFACTORS 32
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/* e.g. an fft of length 128 has 4 factors
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as far as kissfft is concerned
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4*4*4*2
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*/
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struct kiss_fft_state{
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int nfft;
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int inverse;
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int factors[2*MAXFACTORS];
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kiss_fft_cpx twiddles[1];
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};
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/*
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Explanation of macros dealing with complex math:
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C_MUL(m,a,b) : m = a*b
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C_FIXDIV( c , div ) : if a fixed point impl., c /= div. noop otherwise
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C_SUB( res, a,b) : res = a - b
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C_SUBFROM( res , a) : res -= a
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C_ADDTO( res , a) : res += a
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* */
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#ifdef FIXED_POINT
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#if (FIXED_POINT==32)
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# define FRACBITS 31
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# define SAMPPROD int64_t
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#define SAMP_MAX 2147483647
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#else
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# define FRACBITS 15
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# define SAMPPROD int32_t
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#define SAMP_MAX 32767
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#endif
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#define SAMP_MIN -SAMP_MAX
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#if defined(CHECK_OVERFLOW)
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# define CHECK_OVERFLOW_OP(a,op,b) \
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if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
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fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) ); }
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#endif
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# define smul(a,b) ( (SAMPPROD)(a)*(b) )
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# define sround( x ) (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
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# define S_MUL(a,b) sround( smul(a,b) )
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# define C_MUL(m,a,b) \
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do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \
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(m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
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# define DIVSCALAR(x,k) \
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(x) = sround( smul( x, SAMP_MAX/k ) )
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# define C_FIXDIV(c,div) \
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do { DIVSCALAR( (c).r , div); \
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DIVSCALAR( (c).i , div); }while (0)
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# define C_MULBYSCALAR( c, s ) \
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do{ (c).r = sround( smul( (c).r , s ) ) ;\
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(c).i = sround( smul( (c).i , s ) ) ; }while(0)
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#else /* not FIXED_POINT*/
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# define S_MUL(a,b) ( (a)*(b) )
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#define C_MUL(m,a,b) \
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do{ (m).r = (a).r*(b).r - (a).i*(b).i;\
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(m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
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# define C_FIXDIV(c,div) /* NOOP */
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# define C_MULBYSCALAR( c, s ) \
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do{ (c).r *= (s);\
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(c).i *= (s); }while(0)
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#endif
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#ifndef CHECK_OVERFLOW_OP
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# define CHECK_OVERFLOW_OP(a,op,b) /* noop */
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#endif
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#define C_ADD( res, a,b)\
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do { \
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CHECK_OVERFLOW_OP((a).r,+,(b).r)\
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CHECK_OVERFLOW_OP((a).i,+,(b).i)\
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(res).r=(a).r+(b).r; (res).i=(a).i+(b).i; \
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}while(0)
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#define C_SUB( res, a,b)\
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do { \
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CHECK_OVERFLOW_OP((a).r,-,(b).r)\
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CHECK_OVERFLOW_OP((a).i,-,(b).i)\
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(res).r=(a).r-(b).r; (res).i=(a).i-(b).i; \
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}while(0)
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#define C_ADDTO( res , a)\
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do { \
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CHECK_OVERFLOW_OP((res).r,+,(a).r)\
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CHECK_OVERFLOW_OP((res).i,+,(a).i)\
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(res).r += (a).r; (res).i += (a).i;\
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}while(0)
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#define C_SUBFROM( res , a)\
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do {\
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CHECK_OVERFLOW_OP((res).r,-,(a).r)\
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CHECK_OVERFLOW_OP((res).i,-,(a).i)\
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(res).r -= (a).r; (res).i -= (a).i; \
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}while(0)
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#ifdef FIXED_POINT
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# define KISS_FFT_COS(phase) floor(.5+SAMP_MAX * cos (phase))
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# define KISS_FFT_SIN(phase) floor(.5+SAMP_MAX * sin (phase))
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# define HALF_OF(x) ((x)>>1)
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#elif defined(USE_SIMD)
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# define KISS_FFT_COS(phase) _mm_set1_ps( cos(phase) )
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# define KISS_FFT_SIN(phase) _mm_set1_ps( sin(phase) )
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# define HALF_OF(x) ((x)*_mm_set1_ps(.5))
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#else
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# define KISS_FFT_COS(phase) (kiss_fft_scalar) cos(phase)
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# define KISS_FFT_SIN(phase) (kiss_fft_scalar) sin(phase)
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# define HALF_OF(x) ((x)*.5)
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#endif
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#define kf_cexp(x,phase) \
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do{ \
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(x)->r = KISS_FFT_COS(phase);\
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(x)->i = KISS_FFT_SIN(phase);\
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}while(0)
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/* a debugging function */
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#define pcpx(c)\
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fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )
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#ifdef KISS_FFT_USE_ALLOCA
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// define this to allow use of alloca instead of malloc for temporary buffers
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// Temporary buffers are used in two case:
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// 1. FFT sizes that have "bad" factors. i.e. not 2,3 and 5
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// 2. "in-place" FFTs. Notice the quotes, since kissfft does not really do an in-place transform.
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#include <alloca.h>
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#define KISS_FFT_TMP_ALLOC(nbytes) alloca(nbytes)
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#define KISS_FFT_TMP_FREE(ptr)
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#else
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#define KISS_FFT_TMP_ALLOC(nbytes) KISS_FFT_MALLOC(nbytes)
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#define KISS_FFT_TMP_FREE(ptr) KISS_FFT_FREE(ptr)
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#endif
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// Sample from the ADC continuously at a particular sample rate
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// and then compute an FFT over the data
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//
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// much of this code is from pico-examples/adc/dma_capture/dma_capture.c
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// the rest is written by Alex Wulff (www.AlexWulff.com)
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#include <stdio.h>
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#include <math.h>
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#include "pico/stdlib.h"
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#include "hardware/adc.h"
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#include "hardware/dma.h"
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#include "kiss_fftr.h"
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// set this to determine sample rate
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// 0 = 500,000 Hz
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// 960 = 50,000 Hz
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// 9600 = 5,000 Hz
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#define CLOCK_DIV 960
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#define FSAMP 50000
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// Channel 0 is GPIO26
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#define CAPTURE_CHANNEL 0
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#define LED_PIN 25
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// BE CAREFUL: anything over about 9000 here will cause things
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// to silently break. The code will compile and upload, but due
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// to memory issues nothing will work properly
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#define NSAMP 1000
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// globals
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dma_channel_config cfg;
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uint dma_chan;
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float freqs[NSAMP];
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void setup();
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void sample(uint8_t *capture_buf);
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int main() {
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uint8_t cap_buf[NSAMP];
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kiss_fft_scalar fft_in[NSAMP]; // kiss_fft_scalar is a float
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kiss_fft_cpx fft_out[NSAMP];
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kiss_fftr_cfg cfg = kiss_fftr_alloc(NSAMP,false,0,0);
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// setup ports and outputs
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setup();
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while (1) {
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// get NSAMP samples at FSAMP
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sample(cap_buf);
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// fill fourier transform input while subtracting DC component
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uint64_t sum = 0;
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for (int i=0;i<NSAMP;i++) {sum+=cap_buf[i];}
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float avg = (float)sum/NSAMP;
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for (int i=0;i<NSAMP;i++) {fft_in[i]=(float)cap_buf[i]-avg;}
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// compute fast fourier transform
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kiss_fftr(cfg , fft_in, fft_out);
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// compute power and calculate max freq component
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float max_power = 0;
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int max_idx = 0;
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// any frequency bin over NSAMP/2 is aliased (nyquist sampling theorum)
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for (int i = 0; i < NSAMP/2; i++) {
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float power = fft_out[i].r*fft_out[i].r+fft_out[i].i*fft_out[i].i;
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if (power>max_power) {
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max_power=power;
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max_idx = i;
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}
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}
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float max_freq = freqs[max_idx];
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printf("Greatest Frequency Component: %0.1f Hz\n",max_freq);
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}
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// should never get here
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kiss_fft_free(cfg);
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}
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void sample(uint8_t *capture_buf) {
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adc_fifo_drain();
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adc_run(false);
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dma_channel_configure(dma_chan, &cfg,
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capture_buf, // dst
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&adc_hw->fifo, // src
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NSAMP, // transfer count
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true // start immediately
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);
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gpio_put(LED_PIN, 1);
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adc_run(true);
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dma_channel_wait_for_finish_blocking(dma_chan);
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gpio_put(LED_PIN, 0);
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}
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void setup() {
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stdio_init_all();
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gpio_init(LED_PIN);
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gpio_set_dir(LED_PIN, GPIO_OUT);
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adc_gpio_init(26 + CAPTURE_CHANNEL);
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adc_init();
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adc_select_input(CAPTURE_CHANNEL);
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adc_fifo_setup(
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true, // Write each completed conversion to the sample FIFO
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true, // Enable DMA data request (DREQ)
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1, // DREQ (and IRQ) asserted when at least 1 sample present
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false, // We won't see the ERR bit because of 8 bit reads; disable.
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true // Shift each sample to 8 bits when pushing to FIFO
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);
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// set sample rate
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adc_set_clkdiv(CLOCK_DIV);
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sleep_ms(1000);
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// Set up the DMA to start transferring data as soon as it appears in FIFO
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uint dma_chan = dma_claim_unused_channel(true);
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cfg = dma_channel_get_default_config(dma_chan);
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// Reading from constant address, writing to incrementing byte addresses
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channel_config_set_transfer_data_size(&cfg, DMA_SIZE_8);
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channel_config_set_read_increment(&cfg, false);
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channel_config_set_write_increment(&cfg, true);
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// Pace transfers based on availability of ADC samples
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channel_config_set_dreq(&cfg, DREQ_ADC);
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// calculate frequencies of each bin
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float f_max = FSAMP;
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float f_res = f_max / NSAMP;
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for (int i = 0; i < NSAMP; i++) {freqs[i] = f_res*i;}
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}
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// Sample from the ADC continuously at a particular sample rate
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//
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// much of this code is from pico-examples/adc/dma_capture/dma_capture.c
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// the rest is written by Alex Wulff (www.AlexWulff.com)
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#include <stdio.h>
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#include <math.h>
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#include "pico/stdlib.h"
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#include "hardware/adc.h"
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#include "hardware/dma.h"
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// set this to determine sample rate
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// 0 = 500,000 Hz
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// 960 = 50,000 Hz
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// 9600 = 5,000 Hz
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#define CLOCK_DIV 960
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#define FSAMP 50000
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// Channel 0 is GPIO26
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#define CAPTURE_CHANNEL 0
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#define LED_PIN 25
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#define NSAMP 5000
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// constants
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#define PI2 6.2831852
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// globals
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dma_channel_config cfg;
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uint dma_chan;
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float freqs[NSAMP];
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void setup();
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void sample(uint8_t *capture_buf);
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void do_dft(float *in, float *out_re, float *out_im);
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int main() {
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setup();
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uint8_t cap_buf[NSAMP];
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float ft_in[NSAMP];
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float ft_out_re[NSAMP];
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float ft_out_im[NSAMP];
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while (1) {
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// get NSAMP samples at FSAMP
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sample(cap_buf);
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// fill fourier transform input
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for (int i=0;i<NSAMP;i++) {ft_in[i]=(float)cap_buf[i];}
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// perform fourier transform
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do_dft(ft_in, ft_out_re, ft_out_im);
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printf("Sampled!\n");
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}
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}
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void do_dft(float *in, float *out_re, float *out_im) {
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for (int i = 0; i < NSAMP; i++) {
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printf("%f | %f | %f\n",in[i],out_re[i],out_im[i]);
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//out_re[i] = 0; out_im[i] = 0;
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for (int j = 0; j < NSAMP; j++) {
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//out_re[i] += in[j]*sin(PI2*i*j/NSAMP);
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//out_im[i] -= in[j]*cos(PI2*i*j/NSAMP);
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}
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}
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}
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void sample(uint8_t *capture_buf) {
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adc_fifo_drain();
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adc_run(false);
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dma_channel_configure(dma_chan, &cfg,
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capture_buf, // dst
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&adc_hw->fifo, // src
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NSAMP, // transfer count
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true // start immediately
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);
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gpio_put(LED_PIN, 1);
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adc_run(true);
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uint64_t start_time = time_us_64();
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dma_channel_wait_for_finish_blocking(dma_chan);
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uint64_t end_time = time_us_64();
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gpio_put(LED_PIN, 0);
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}
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void setup() {
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stdio_init_all();
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gpio_init(LED_PIN);
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gpio_set_dir(LED_PIN, GPIO_OUT);
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adc_gpio_init(26 + CAPTURE_CHANNEL);
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adc_init();
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adc_select_input(CAPTURE_CHANNEL);
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adc_fifo_setup(
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true, // Write each completed conversion to the sample FIFO
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true, // Enable DMA data request (DREQ)
|
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1, // DREQ (and IRQ) asserted when at least 1 sample present
|
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false, // We won't see the ERR bit because of 8 bit reads; disable.
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true // Shift each sample to 8 bits when pushing to FIFO
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);
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// set sample rate
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adc_set_clkdiv(CLOCK_DIV);
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sleep_ms(1000);
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// Set up the DMA to start transferring data as soon as it appears in FIFO
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dma_chan = dma_claim_unused_channel(true);
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cfg = dma_channel_get_default_config(dma_chan);
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|
||||
// Reading from constant address, writing to incrementing byte addresses
|
||||
channel_config_set_transfer_data_size(&cfg, DMA_SIZE_8);
|
||||
channel_config_set_read_increment(&cfg, false);
|
||||
channel_config_set_write_increment(&cfg, true);
|
||||
|
||||
// Pace transfers based on availability of ADC samples
|
||||
channel_config_set_dreq(&cfg, DREQ_ADC);
|
||||
|
||||
// calculate frequencies of each bin
|
||||
float f_max = FSAMP/2;
|
||||
float f_res = f_max / NSAMP;
|
||||
for (int i = 0; i < NSAMP; i++) {freqs[i] = f_res*i;}
|
||||
}
|
||||
|
|
@ -0,0 +1,408 @@
|
|||
/*
|
||||
Copyright (c) 2003-2010, Mark Borgerding
|
||||
|
||||
All rights reserved.
|
||||
|
||||
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
|
||||
|
||||
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
|
||||
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
|
||||
* Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
|
||||
|
||||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
|
||||
#include "_kiss_fft_guts.h"
|
||||
/* The guts header contains all the multiplication and addition macros that are defined for
|
||||
fixed or floating point complex numbers. It also delares the kf_ internal functions.
|
||||
*/
|
||||
|
||||
static void kf_bfly2(
|
||||
kiss_fft_cpx * Fout,
|
||||
const size_t fstride,
|
||||
const kiss_fft_cfg st,
|
||||
int m
|
||||
)
|
||||
{
|
||||
kiss_fft_cpx * Fout2;
|
||||
kiss_fft_cpx * tw1 = st->twiddles;
|
||||
kiss_fft_cpx t;
|
||||
Fout2 = Fout + m;
|
||||
do{
|
||||
C_FIXDIV(*Fout,2); C_FIXDIV(*Fout2,2);
|
||||
|
||||
C_MUL (t, *Fout2 , *tw1);
|
||||
tw1 += fstride;
|
||||
C_SUB( *Fout2 , *Fout , t );
|
||||
C_ADDTO( *Fout , t );
|
||||
++Fout2;
|
||||
++Fout;
|
||||
}while (--m);
|
||||
}
|
||||
|
||||
static void kf_bfly4(
|
||||
kiss_fft_cpx * Fout,
|
||||
const size_t fstride,
|
||||
const kiss_fft_cfg st,
|
||||
const size_t m
|
||||
)
|
||||
{
|
||||
kiss_fft_cpx *tw1,*tw2,*tw3;
|
||||
kiss_fft_cpx scratch[6];
|
||||
size_t k=m;
|
||||
const size_t m2=2*m;
|
||||
const size_t m3=3*m;
|
||||
|
||||
|
||||
tw3 = tw2 = tw1 = st->twiddles;
|
||||
|
||||
do {
|
||||
C_FIXDIV(*Fout,4); C_FIXDIV(Fout[m],4); C_FIXDIV(Fout[m2],4); C_FIXDIV(Fout[m3],4);
|
||||
|
||||
C_MUL(scratch[0],Fout[m] , *tw1 );
|
||||
C_MUL(scratch[1],Fout[m2] , *tw2 );
|
||||
C_MUL(scratch[2],Fout[m3] , *tw3 );
|
||||
|
||||
C_SUB( scratch[5] , *Fout, scratch[1] );
|
||||
C_ADDTO(*Fout, scratch[1]);
|
||||
C_ADD( scratch[3] , scratch[0] , scratch[2] );
|
||||
C_SUB( scratch[4] , scratch[0] , scratch[2] );
|
||||
C_SUB( Fout[m2], *Fout, scratch[3] );
|
||||
tw1 += fstride;
|
||||
tw2 += fstride*2;
|
||||
tw3 += fstride*3;
|
||||
C_ADDTO( *Fout , scratch[3] );
|
||||
|
||||
if(st->inverse) {
|
||||
Fout[m].r = scratch[5].r - scratch[4].i;
|
||||
Fout[m].i = scratch[5].i + scratch[4].r;
|
||||
Fout[m3].r = scratch[5].r + scratch[4].i;
|
||||
Fout[m3].i = scratch[5].i - scratch[4].r;
|
||||
}else{
|
||||
Fout[m].r = scratch[5].r + scratch[4].i;
|
||||
Fout[m].i = scratch[5].i - scratch[4].r;
|
||||
Fout[m3].r = scratch[5].r - scratch[4].i;
|
||||
Fout[m3].i = scratch[5].i + scratch[4].r;
|
||||
}
|
||||
++Fout;
|
||||
}while(--k);
|
||||
}
|
||||
|
||||
static void kf_bfly3(
|
||||
kiss_fft_cpx * Fout,
|
||||
const size_t fstride,
|
||||
const kiss_fft_cfg st,
|
||||
size_t m
|
||||
)
|
||||
{
|
||||
size_t k=m;
|
||||
const size_t m2 = 2*m;
|
||||
kiss_fft_cpx *tw1,*tw2;
|
||||
kiss_fft_cpx scratch[5];
|
||||
kiss_fft_cpx epi3;
|
||||
epi3 = st->twiddles[fstride*m];
|
||||
|
||||
tw1=tw2=st->twiddles;
|
||||
|
||||
do{
|
||||
C_FIXDIV(*Fout,3); C_FIXDIV(Fout[m],3); C_FIXDIV(Fout[m2],3);
|
||||
|
||||
C_MUL(scratch[1],Fout[m] , *tw1);
|
||||
C_MUL(scratch[2],Fout[m2] , *tw2);
|
||||
|
||||
C_ADD(scratch[3],scratch[1],scratch[2]);
|
||||
C_SUB(scratch[0],scratch[1],scratch[2]);
|
||||
tw1 += fstride;
|
||||
tw2 += fstride*2;
|
||||
|
||||
Fout[m].r = Fout->r - HALF_OF(scratch[3].r);
|
||||
Fout[m].i = Fout->i - HALF_OF(scratch[3].i);
|
||||
|
||||
C_MULBYSCALAR( scratch[0] , epi3.i );
|
||||
|
||||
C_ADDTO(*Fout,scratch[3]);
|
||||
|
||||
Fout[m2].r = Fout[m].r + scratch[0].i;
|
||||
Fout[m2].i = Fout[m].i - scratch[0].r;
|
||||
|
||||
Fout[m].r -= scratch[0].i;
|
||||
Fout[m].i += scratch[0].r;
|
||||
|
||||
++Fout;
|
||||
}while(--k);
|
||||
}
|
||||
|
||||
static void kf_bfly5(
|
||||
kiss_fft_cpx * Fout,
|
||||
const size_t fstride,
|
||||
const kiss_fft_cfg st,
|
||||
int m
|
||||
)
|
||||
{
|
||||
kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
|
||||
int u;
|
||||
kiss_fft_cpx scratch[13];
|
||||
kiss_fft_cpx * twiddles = st->twiddles;
|
||||
kiss_fft_cpx *tw;
|
||||
kiss_fft_cpx ya,yb;
|
||||
ya = twiddles[fstride*m];
|
||||
yb = twiddles[fstride*2*m];
|
||||
|
||||
Fout0=Fout;
|
||||
Fout1=Fout0+m;
|
||||
Fout2=Fout0+2*m;
|
||||
Fout3=Fout0+3*m;
|
||||
Fout4=Fout0+4*m;
|
||||
|
||||
tw=st->twiddles;
|
||||
for ( u=0; u<m; ++u ) {
|
||||
C_FIXDIV( *Fout0,5); C_FIXDIV( *Fout1,5); C_FIXDIV( *Fout2,5); C_FIXDIV( *Fout3,5); C_FIXDIV( *Fout4,5);
|
||||
scratch[0] = *Fout0;
|
||||
|
||||
C_MUL(scratch[1] ,*Fout1, tw[u*fstride]);
|
||||
C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]);
|
||||
C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]);
|
||||
C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]);
|
||||
|
||||
C_ADD( scratch[7],scratch[1],scratch[4]);
|
||||
C_SUB( scratch[10],scratch[1],scratch[4]);
|
||||
C_ADD( scratch[8],scratch[2],scratch[3]);
|
||||
C_SUB( scratch[9],scratch[2],scratch[3]);
|
||||
|
||||
Fout0->r += scratch[7].r + scratch[8].r;
|
||||
Fout0->i += scratch[7].i + scratch[8].i;
|
||||
|
||||
scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
|
||||
scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);
|
||||
|
||||
scratch[6].r = S_MUL(scratch[10].i,ya.i) + S_MUL(scratch[9].i,yb.i);
|
||||
scratch[6].i = -S_MUL(scratch[10].r,ya.i) - S_MUL(scratch[9].r,yb.i);
|
||||
|
||||
C_SUB(*Fout1,scratch[5],scratch[6]);
|
||||
C_ADD(*Fout4,scratch[5],scratch[6]);
|
||||
|
||||
scratch[11].r = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
|
||||
scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
|
||||
scratch[12].r = - S_MUL(scratch[10].i,yb.i) + S_MUL(scratch[9].i,ya.i);
|
||||
scratch[12].i = S_MUL(scratch[10].r,yb.i) - S_MUL(scratch[9].r,ya.i);
|
||||
|
||||
C_ADD(*Fout2,scratch[11],scratch[12]);
|
||||
C_SUB(*Fout3,scratch[11],scratch[12]);
|
||||
|
||||
++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
|
||||
}
|
||||
}
|
||||
|
||||
/* perform the butterfly for one stage of a mixed radix FFT */
|
||||
static void kf_bfly_generic(
|
||||
kiss_fft_cpx * Fout,
|
||||
const size_t fstride,
|
||||
const kiss_fft_cfg st,
|
||||
int m,
|
||||
int p
|
||||
)
|
||||
{
|
||||
int u,k,q1,q;
|
||||
kiss_fft_cpx * twiddles = st->twiddles;
|
||||
kiss_fft_cpx t;
|
||||
int Norig = st->nfft;
|
||||
|
||||
kiss_fft_cpx * scratch = (kiss_fft_cpx*)KISS_FFT_TMP_ALLOC(sizeof(kiss_fft_cpx)*p);
|
||||
|
||||
for ( u=0; u<m; ++u ) {
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
scratch[q1] = Fout[ k ];
|
||||
C_FIXDIV(scratch[q1],p);
|
||||
k += m;
|
||||
}
|
||||
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
int twidx=0;
|
||||
Fout[ k ] = scratch[0];
|
||||
for (q=1;q<p;++q ) {
|
||||
twidx += fstride * k;
|
||||
if (twidx>=Norig) twidx-=Norig;
|
||||
C_MUL(t,scratch[q] , twiddles[twidx] );
|
||||
C_ADDTO( Fout[ k ] ,t);
|
||||
}
|
||||
k += m;
|
||||
}
|
||||
}
|
||||
KISS_FFT_TMP_FREE(scratch);
|
||||
}
|
||||
|
||||
static
|
||||
void kf_work(
|
||||
kiss_fft_cpx * Fout,
|
||||
const kiss_fft_cpx * f,
|
||||
const size_t fstride,
|
||||
int in_stride,
|
||||
int * factors,
|
||||
const kiss_fft_cfg st
|
||||
)
|
||||
{
|
||||
kiss_fft_cpx * Fout_beg=Fout;
|
||||
const int p=*factors++; /* the radix */
|
||||
const int m=*factors++; /* stage's fft length/p */
|
||||
const kiss_fft_cpx * Fout_end = Fout + p*m;
|
||||
|
||||
#ifdef _OPENMP
|
||||
// use openmp extensions at the
|
||||
// top-level (not recursive)
|
||||
if (fstride==1 && p<=5)
|
||||
{
|
||||
int k;
|
||||
|
||||
// execute the p different work units in different threads
|
||||
# pragma omp parallel for
|
||||
for (k=0;k<p;++k)
|
||||
kf_work( Fout +k*m, f+ fstride*in_stride*k,fstride*p,in_stride,factors,st);
|
||||
// all threads have joined by this point
|
||||
|
||||
switch (p) {
|
||||
case 2: kf_bfly2(Fout,fstride,st,m); break;
|
||||
case 3: kf_bfly3(Fout,fstride,st,m); break;
|
||||
case 4: kf_bfly4(Fout,fstride,st,m); break;
|
||||
case 5: kf_bfly5(Fout,fstride,st,m); break;
|
||||
default: kf_bfly_generic(Fout,fstride,st,m,p); break;
|
||||
}
|
||||
return;
|
||||
}
|
||||
#endif
|
||||
|
||||
if (m==1) {
|
||||
do{
|
||||
*Fout = *f;
|
||||
f += fstride*in_stride;
|
||||
}while(++Fout != Fout_end );
|
||||
}else{
|
||||
do{
|
||||
// recursive call:
|
||||
// DFT of size m*p performed by doing
|
||||
// p instances of smaller DFTs of size m,
|
||||
// each one takes a decimated version of the input
|
||||
kf_work( Fout , f, fstride*p, in_stride, factors,st);
|
||||
f += fstride*in_stride;
|
||||
}while( (Fout += m) != Fout_end );
|
||||
}
|
||||
|
||||
Fout=Fout_beg;
|
||||
|
||||
// recombine the p smaller DFTs
|
||||
switch (p) {
|
||||
case 2: kf_bfly2(Fout,fstride,st,m); break;
|
||||
case 3: kf_bfly3(Fout,fstride,st,m); break;
|
||||
case 4: kf_bfly4(Fout,fstride,st,m); break;
|
||||
case 5: kf_bfly5(Fout,fstride,st,m); break;
|
||||
default: kf_bfly_generic(Fout,fstride,st,m,p); break;
|
||||
}
|
||||
}
|
||||
|
||||
/* facbuf is populated by p1,m1,p2,m2, ...
|
||||
where
|
||||
p[i] * m[i] = m[i-1]
|
||||
m0 = n */
|
||||
static
|
||||
void kf_factor(int n,int * facbuf)
|
||||
{
|
||||
int p=4;
|
||||
double floor_sqrt;
|
||||
floor_sqrt = floor( sqrt((double)n) );
|
||||
|
||||
/*factor out powers of 4, powers of 2, then any remaining primes */
|
||||
do {
|
||||
while (n % p) {
|
||||
switch (p) {
|
||||
case 4: p = 2; break;
|
||||
case 2: p = 3; break;
|
||||
default: p += 2; break;
|
||||
}
|
||||
if (p > floor_sqrt)
|
||||
p = n; /* no more factors, skip to end */
|
||||
}
|
||||
n /= p;
|
||||
*facbuf++ = p;
|
||||
*facbuf++ = n;
|
||||
} while (n > 1);
|
||||
}
|
||||
|
||||
/*
|
||||
*
|
||||
* User-callable function to allocate all necessary storage space for the fft.
|
||||
*
|
||||
* The return value is a contiguous block of memory, allocated with malloc. As such,
|
||||
* It can be freed with free(), rather than a kiss_fft-specific function.
|
||||
* */
|
||||
kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem )
|
||||
{
|
||||
kiss_fft_cfg st=NULL;
|
||||
size_t memneeded = sizeof(struct kiss_fft_state)
|
||||
+ sizeof(kiss_fft_cpx)*(nfft-1); /* twiddle factors*/
|
||||
|
||||
if ( lenmem==NULL ) {
|
||||
st = ( kiss_fft_cfg)KISS_FFT_MALLOC( memneeded );
|
||||
}else{
|
||||
if (mem != NULL && *lenmem >= memneeded)
|
||||
st = (kiss_fft_cfg)mem;
|
||||
*lenmem = memneeded;
|
||||
}
|
||||
if (st) {
|
||||
int i;
|
||||
st->nfft=nfft;
|
||||
st->inverse = inverse_fft;
|
||||
|
||||
for (i=0;i<nfft;++i) {
|
||||
const double pi=3.141592653589793238462643383279502884197169399375105820974944;
|
||||
double phase = -2*pi*i / nfft;
|
||||
if (st->inverse)
|
||||
phase *= -1;
|
||||
kf_cexp(st->twiddles+i, phase );
|
||||
}
|
||||
|
||||
kf_factor(nfft,st->factors);
|
||||
}
|
||||
return st;
|
||||
}
|
||||
|
||||
|
||||
void kiss_fft_stride(kiss_fft_cfg st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int in_stride)
|
||||
{
|
||||
if (fin == fout) {
|
||||
//NOTE: this is not really an in-place FFT algorithm.
|
||||
//It just performs an out-of-place FFT into a temp buffer
|
||||
kiss_fft_cpx * tmpbuf = (kiss_fft_cpx*)KISS_FFT_TMP_ALLOC( sizeof(kiss_fft_cpx)*st->nfft);
|
||||
kf_work(tmpbuf,fin,1,in_stride, st->factors,st);
|
||||
memcpy(fout,tmpbuf,sizeof(kiss_fft_cpx)*st->nfft);
|
||||
KISS_FFT_TMP_FREE(tmpbuf);
|
||||
}else{
|
||||
kf_work( fout, fin, 1,in_stride, st->factors,st );
|
||||
}
|
||||
}
|
||||
|
||||
void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
|
||||
{
|
||||
kiss_fft_stride(cfg,fin,fout,1);
|
||||
}
|
||||
|
||||
|
||||
void kiss_fft_cleanup(void)
|
||||
{
|
||||
// nothing needed any more
|
||||
}
|
||||
|
||||
int kiss_fft_next_fast_size(int n)
|
||||
{
|
||||
while(1) {
|
||||
int m=n;
|
||||
while ( (m%2) == 0 ) m/=2;
|
||||
while ( (m%3) == 0 ) m/=3;
|
||||
while ( (m%5) == 0 ) m/=5;
|
||||
if (m<=1)
|
||||
break; /* n is completely factorable by twos, threes, and fives */
|
||||
n++;
|
||||
}
|
||||
return n;
|
||||
}
|
||||
|
|
@ -0,0 +1,124 @@
|
|||
#ifndef KISS_FFT_H
|
||||
#define KISS_FFT_H
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <math.h>
|
||||
#include <string.h>
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
/*
|
||||
ATTENTION!
|
||||
If you would like a :
|
||||
-- a utility that will handle the caching of fft objects
|
||||
-- real-only (no imaginary time component ) FFT
|
||||
-- a multi-dimensional FFT
|
||||
-- a command-line utility to perform ffts
|
||||
-- a command-line utility to perform fast-convolution filtering
|
||||
|
||||
Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
|
||||
in the tools/ directory.
|
||||
*/
|
||||
|
||||
#ifdef USE_SIMD
|
||||
# include <xmmintrin.h>
|
||||
# define kiss_fft_scalar __m128
|
||||
#define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
|
||||
#define KISS_FFT_FREE _mm_free
|
||||
#else
|
||||
#define KISS_FFT_MALLOC malloc
|
||||
#define KISS_FFT_FREE free
|
||||
#endif
|
||||
|
||||
|
||||
#ifdef FIXED_POINT
|
||||
#include <sys/types.h>
|
||||
# if (FIXED_POINT == 32)
|
||||
# define kiss_fft_scalar int32_t
|
||||
# else
|
||||
# define kiss_fft_scalar int16_t
|
||||
# endif
|
||||
#else
|
||||
# ifndef kiss_fft_scalar
|
||||
/* default is float */
|
||||
# define kiss_fft_scalar float
|
||||
# endif
|
||||
#endif
|
||||
|
||||
typedef struct {
|
||||
kiss_fft_scalar r;
|
||||
kiss_fft_scalar i;
|
||||
}kiss_fft_cpx;
|
||||
|
||||
typedef struct kiss_fft_state* kiss_fft_cfg;
|
||||
|
||||
/*
|
||||
* kiss_fft_alloc
|
||||
*
|
||||
* Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
|
||||
*
|
||||
* typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
|
||||
*
|
||||
* The return value from fft_alloc is a cfg buffer used internally
|
||||
* by the fft routine or NULL.
|
||||
*
|
||||
* If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
|
||||
* The returned value should be free()d when done to avoid memory leaks.
|
||||
*
|
||||
* The state can be placed in a user supplied buffer 'mem':
|
||||
* If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
|
||||
* then the function places the cfg in mem and the size used in *lenmem
|
||||
* and returns mem.
|
||||
*
|
||||
* If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
|
||||
* then the function returns NULL and places the minimum cfg
|
||||
* buffer size in *lenmem.
|
||||
* */
|
||||
|
||||
kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
|
||||
|
||||
/*
|
||||
* kiss_fft(cfg,in_out_buf)
|
||||
*
|
||||
* Perform an FFT on a complex input buffer.
|
||||
* for a forward FFT,
|
||||
* fin should be f[0] , f[1] , ... ,f[nfft-1]
|
||||
* fout will be F[0] , F[1] , ... ,F[nfft-1]
|
||||
* Note that each element is complex and can be accessed like
|
||||
f[k].r and f[k].i
|
||||
* */
|
||||
void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
|
||||
|
||||
/*
|
||||
A more generic version of the above function. It reads its input from every Nth sample.
|
||||
* */
|
||||
void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
|
||||
|
||||
/* If kiss_fft_alloc allocated a buffer, it is one contiguous
|
||||
buffer and can be simply free()d when no longer needed*/
|
||||
#define kiss_fft_free free
|
||||
|
||||
/*
|
||||
Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
|
||||
your compiler output to call this before you exit.
|
||||
*/
|
||||
void kiss_fft_cleanup(void);
|
||||
|
||||
|
||||
/*
|
||||
* Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
|
||||
*/
|
||||
int kiss_fft_next_fast_size(int n);
|
||||
|
||||
/* for real ffts, we need an even size */
|
||||
#define kiss_fftr_next_fast_size_real(n) \
|
||||
(kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif
|
||||
|
|
@ -0,0 +1,159 @@
|
|||
/*
|
||||
Copyright (c) 2003-2004, Mark Borgerding
|
||||
|
||||
All rights reserved.
|
||||
|
||||
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
|
||||
|
||||
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
|
||||
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
|
||||
* Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
|
||||
|
||||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include "kiss_fftr.h"
|
||||
#include "_kiss_fft_guts.h"
|
||||
|
||||
struct kiss_fftr_state{
|
||||
kiss_fft_cfg substate;
|
||||
kiss_fft_cpx * tmpbuf;
|
||||
kiss_fft_cpx * super_twiddles;
|
||||
#ifdef USE_SIMD
|
||||
void * pad;
|
||||
#endif
|
||||
};
|
||||
|
||||
kiss_fftr_cfg kiss_fftr_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem)
|
||||
{
|
||||
int i;
|
||||
kiss_fftr_cfg st = NULL;
|
||||
size_t subsize, memneeded;
|
||||
|
||||
if (nfft & 1) {
|
||||
fprintf(stderr,"Real FFT optimization must be even.\n");
|
||||
return NULL;
|
||||
}
|
||||
nfft >>= 1;
|
||||
|
||||
kiss_fft_alloc (nfft, inverse_fft, NULL, &subsize);
|
||||
memneeded = sizeof(struct kiss_fftr_state) + subsize + sizeof(kiss_fft_cpx) * ( nfft * 3 / 2);
|
||||
|
||||
if (lenmem == NULL) {
|
||||
st = (kiss_fftr_cfg) KISS_FFT_MALLOC (memneeded);
|
||||
} else {
|
||||
if (*lenmem >= memneeded)
|
||||
st = (kiss_fftr_cfg) mem;
|
||||
*lenmem = memneeded;
|
||||
}
|
||||
if (!st)
|
||||
return NULL;
|
||||
|
||||
st->substate = (kiss_fft_cfg) (st + 1); /*just beyond kiss_fftr_state struct */
|
||||
st->tmpbuf = (kiss_fft_cpx *) (((char *) st->substate) + subsize);
|
||||
st->super_twiddles = st->tmpbuf + nfft;
|
||||
kiss_fft_alloc(nfft, inverse_fft, st->substate, &subsize);
|
||||
|
||||
for (i = 0; i < nfft/2; ++i) {
|
||||
double phase =
|
||||
-3.14159265358979323846264338327 * ((double) (i+1) / nfft + .5);
|
||||
if (inverse_fft)
|
||||
phase *= -1;
|
||||
kf_cexp (st->super_twiddles+i,phase);
|
||||
}
|
||||
return st;
|
||||
}
|
||||
|
||||
void kiss_fftr(kiss_fftr_cfg st,const kiss_fft_scalar *timedata,kiss_fft_cpx *freqdata)
|
||||
{
|
||||
/* input buffer timedata is stored row-wise */
|
||||
int k,ncfft;
|
||||
kiss_fft_cpx fpnk,fpk,f1k,f2k,tw,tdc;
|
||||
|
||||
if ( st->substate->inverse) {
|
||||
fprintf(stderr,"kiss fft usage error: improper alloc\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
ncfft = st->substate->nfft;
|
||||
|
||||
/*perform the parallel fft of two real signals packed in real,imag*/
|
||||
kiss_fft( st->substate , (const kiss_fft_cpx*)timedata, st->tmpbuf );
|
||||
/* The real part of the DC element of the frequency spectrum in st->tmpbuf
|
||||
* contains the sum of the even-numbered elements of the input time sequence
|
||||
* The imag part is the sum of the odd-numbered elements
|
||||
*
|
||||
* The sum of tdc.r and tdc.i is the sum of the input time sequence.
|
||||
* yielding DC of input time sequence
|
||||
* The difference of tdc.r - tdc.i is the sum of the input (dot product) [1,-1,1,-1...
|
||||
* yielding Nyquist bin of input time sequence
|
||||
*/
|
||||
|
||||
tdc.r = st->tmpbuf[0].r;
|
||||
tdc.i = st->tmpbuf[0].i;
|
||||
C_FIXDIV(tdc,2);
|
||||
CHECK_OVERFLOW_OP(tdc.r ,+, tdc.i);
|
||||
CHECK_OVERFLOW_OP(tdc.r ,-, tdc.i);
|
||||
freqdata[0].r = tdc.r + tdc.i;
|
||||
freqdata[ncfft].r = tdc.r - tdc.i;
|
||||
#ifdef USE_SIMD
|
||||
freqdata[ncfft].i = freqdata[0].i = _mm_set1_ps(0);
|
||||
#else
|
||||
freqdata[ncfft].i = freqdata[0].i = 0;
|
||||
#endif
|
||||
|
||||
for ( k=1;k <= ncfft/2 ; ++k ) {
|
||||
fpk = st->tmpbuf[k];
|
||||
fpnk.r = st->tmpbuf[ncfft-k].r;
|
||||
fpnk.i = - st->tmpbuf[ncfft-k].i;
|
||||
C_FIXDIV(fpk,2);
|
||||
C_FIXDIV(fpnk,2);
|
||||
|
||||
C_ADD( f1k, fpk , fpnk );
|
||||
C_SUB( f2k, fpk , fpnk );
|
||||
C_MUL( tw , f2k , st->super_twiddles[k-1]);
|
||||
|
||||
freqdata[k].r = HALF_OF(f1k.r + tw.r);
|
||||
freqdata[k].i = HALF_OF(f1k.i + tw.i);
|
||||
freqdata[ncfft-k].r = HALF_OF(f1k.r - tw.r);
|
||||
freqdata[ncfft-k].i = HALF_OF(tw.i - f1k.i);
|
||||
}
|
||||
}
|
||||
|
||||
void kiss_fftri(kiss_fftr_cfg st,const kiss_fft_cpx *freqdata,kiss_fft_scalar *timedata)
|
||||
{
|
||||
/* input buffer timedata is stored row-wise */
|
||||
int k, ncfft;
|
||||
|
||||
if (st->substate->inverse == 0) {
|
||||
fprintf (stderr, "kiss fft usage error: improper alloc\n");
|
||||
exit (1);
|
||||
}
|
||||
|
||||
ncfft = st->substate->nfft;
|
||||
|
||||
st->tmpbuf[0].r = freqdata[0].r + freqdata[ncfft].r;
|
||||
st->tmpbuf[0].i = freqdata[0].r - freqdata[ncfft].r;
|
||||
C_FIXDIV(st->tmpbuf[0],2);
|
||||
|
||||
for (k = 1; k <= ncfft / 2; ++k) {
|
||||
kiss_fft_cpx fk, fnkc, fek, fok, tmp;
|
||||
fk = freqdata[k];
|
||||
fnkc.r = freqdata[ncfft - k].r;
|
||||
fnkc.i = -freqdata[ncfft - k].i;
|
||||
C_FIXDIV( fk , 2 );
|
||||
C_FIXDIV( fnkc , 2 );
|
||||
|
||||
C_ADD (fek, fk, fnkc);
|
||||
C_SUB (tmp, fk, fnkc);
|
||||
C_MUL (fok, tmp, st->super_twiddles[k-1]);
|
||||
C_ADD (st->tmpbuf[k], fek, fok);
|
||||
C_SUB (st->tmpbuf[ncfft - k], fek, fok);
|
||||
#ifdef USE_SIMD
|
||||
st->tmpbuf[ncfft - k].i *= _mm_set1_ps(-1.0);
|
||||
#else
|
||||
st->tmpbuf[ncfft - k].i *= -1;
|
||||
#endif
|
||||
}
|
||||
kiss_fft (st->substate, st->tmpbuf, (kiss_fft_cpx *) timedata);
|
||||
}
|
||||
|
|
@ -0,0 +1,46 @@
|
|||
#ifndef KISS_FTR_H
|
||||
#define KISS_FTR_H
|
||||
|
||||
#include "kiss_fft.h"
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
|
||||
/*
|
||||
|
||||
Real optimized version can save about 45% cpu time vs. complex fft of a real seq.
|
||||
|
||||
|
||||
|
||||
*/
|
||||
|
||||
typedef struct kiss_fftr_state *kiss_fftr_cfg;
|
||||
|
||||
|
||||
kiss_fftr_cfg kiss_fftr_alloc(int nfft,int inverse_fft,void * mem, size_t * lenmem);
|
||||
/*
|
||||
nfft must be even
|
||||
|
||||
If you don't care to allocate space, use mem = lenmem = NULL
|
||||
*/
|
||||
|
||||
|
||||
void kiss_fftr(kiss_fftr_cfg cfg,const kiss_fft_scalar *timedata,kiss_fft_cpx *freqdata);
|
||||
/*
|
||||
input timedata has nfft scalar points
|
||||
output freqdata has nfft/2+1 complex points
|
||||
*/
|
||||
|
||||
void kiss_fftri(kiss_fftr_cfg cfg,const kiss_fft_cpx *freqdata,kiss_fft_scalar *timedata);
|
||||
/*
|
||||
input freqdata has nfft/2+1 complex points
|
||||
output timedata has nfft scalar points
|
||||
*/
|
||||
|
||||
#define kiss_fftr_free free
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
#endif
|
||||
|
|
@ -0,0 +1,62 @@
|
|||
# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
|
||||
|
||||
# This can be dropped into an external project to help locate this SDK
|
||||
# It should be include()ed prior to project()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
|
||||
set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
|
||||
message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
|
||||
endif ()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
|
||||
set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
|
||||
message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
|
||||
endif ()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
|
||||
set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
|
||||
message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the PICO SDK")
|
||||
set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of PICO SDK from git if not otherwise locatable")
|
||||
set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
|
||||
|
||||
if (NOT PICO_SDK_PATH)
|
||||
if (PICO_SDK_FETCH_FROM_GIT)
|
||||
include(FetchContent)
|
||||
set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
|
||||
if (PICO_SDK_FETCH_FROM_GIT_PATH)
|
||||
get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
|
||||
endif ()
|
||||
FetchContent_Declare(
|
||||
pico_sdk
|
||||
GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
|
||||
GIT_TAG master
|
||||
)
|
||||
if (NOT pico_sdk)
|
||||
message("Downloading PICO SDK")
|
||||
FetchContent_Populate(pico_sdk)
|
||||
set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
|
||||
endif ()
|
||||
set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
|
||||
else ()
|
||||
message(FATAL_ERROR
|
||||
"PICO SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
|
||||
)
|
||||
endif ()
|
||||
endif ()
|
||||
|
||||
get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
|
||||
if (NOT EXISTS ${PICO_SDK_PATH})
|
||||
message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
|
||||
if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
|
||||
message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the PICO SDK")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the PICO SDK" FORCE)
|
||||
|
||||
include(${PICO_SDK_INIT_CMAKE_FILE})
|
||||
|
|
@ -0,0 +1,22 @@
|
|||
cmake_minimum_required(VERSION 3.12)
|
||||
|
||||
include(pico_sdk_import.cmake)
|
||||
|
||||
project(adc_time_project)
|
||||
|
||||
pico_sdk_init()
|
||||
|
||||
add_executable(adc_time
|
||||
adc_time.c
|
||||
)
|
||||
|
||||
pico_enable_stdio_usb(adc_time 1)
|
||||
pico_enable_stdio_uart(adc_time 1)
|
||||
|
||||
pico_add_extra_outputs(adc_time)
|
||||
|
||||
target_link_libraries(adc_time
|
||||
pico_stdlib
|
||||
hardware_adc
|
||||
hardware_dma
|
||||
)
|
||||
|
|
@ -0,0 +1,83 @@
|
|||
// Sample from the ADC continuously at a particular sample rate
|
||||
//
|
||||
// much of this code is from pico-examples/adc/dma_capture/dma_capture.c
|
||||
// the rest is written by Alex Wulff (www.AlexWulff.com)
|
||||
|
||||
#include <stdio.h>
|
||||
#include "pico/stdlib.h"
|
||||
#include "hardware/adc.h"
|
||||
#include "hardware/dma.h"
|
||||
|
||||
// set this to determine sample rate
|
||||
// 0 = 500,000 Hz
|
||||
// 960 = 50,000 Hz
|
||||
// 9600 = 5,000 Hz
|
||||
#define CLOCK_DIV 9600
|
||||
|
||||
// Channel 0 is GPIO26
|
||||
#define CAPTURE_CHANNEL 0
|
||||
#define LED_PIN 25
|
||||
#define NSAMP 10000
|
||||
|
||||
uint8_t capture_buf[NSAMP];
|
||||
|
||||
int main() {
|
||||
stdio_init_all();
|
||||
|
||||
gpio_init(LED_PIN);
|
||||
gpio_set_dir(LED_PIN, GPIO_OUT);
|
||||
adc_gpio_init(26 + CAPTURE_CHANNEL);
|
||||
|
||||
adc_init();
|
||||
adc_select_input(CAPTURE_CHANNEL);
|
||||
adc_fifo_setup(
|
||||
true, // Write each completed conversion to the sample FIFO
|
||||
true, // Enable DMA data request (DREQ)
|
||||
1, // DREQ (and IRQ) asserted when at least 1 sample present
|
||||
false, // We won't see the ERR bit because of 8 bit reads; disable.
|
||||
true // Shift each sample to 8 bits when pushing to FIFO
|
||||
);
|
||||
|
||||
// set sample rate
|
||||
adc_set_clkdiv(CLOCK_DIV);
|
||||
|
||||
sleep_ms(1000);
|
||||
// Set up the DMA to start transferring data as soon as it appears in FIFO
|
||||
uint dma_chan = dma_claim_unused_channel(true);
|
||||
dma_channel_config cfg = dma_channel_get_default_config(dma_chan);
|
||||
|
||||
// Reading from constant address, writing to incrementing byte addresses
|
||||
channel_config_set_transfer_data_size(&cfg, DMA_SIZE_8);
|
||||
channel_config_set_read_increment(&cfg, false);
|
||||
channel_config_set_write_increment(&cfg, true);
|
||||
|
||||
// Pace transfers based on availability of ADC samples
|
||||
channel_config_set_dreq(&cfg, DREQ_ADC);
|
||||
|
||||
while (1) {
|
||||
adc_fifo_drain();
|
||||
adc_run(false);
|
||||
|
||||
dma_channel_configure(dma_chan, &cfg,
|
||||
capture_buf, // dst
|
||||
&adc_hw->fifo, // src
|
||||
NSAMP, // transfer count
|
||||
true // start immediately
|
||||
);
|
||||
|
||||
gpio_put(LED_PIN, 1);
|
||||
adc_run(true);
|
||||
|
||||
uint64_t start_time = time_us_64();
|
||||
dma_channel_wait_for_finish_blocking(dma_chan);
|
||||
uint64_t end_time = time_us_64();
|
||||
gpio_put(LED_PIN, 0);
|
||||
|
||||
uint64_t time_diff_us = end_time-start_time;
|
||||
float sample_time = time_diff_us/1e6;
|
||||
|
||||
printf("us: %llu | Total Time: %f s\n", time_diff_us, sample_time);
|
||||
printf("Sample Rate: %0.1f Hz\n", NSAMP/(sample_time));
|
||||
sleep_ms(1000);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,62 @@
|
|||
# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
|
||||
|
||||
# This can be dropped into an external project to help locate this SDK
|
||||
# It should be include()ed prior to project()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
|
||||
set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
|
||||
message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
|
||||
endif ()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
|
||||
set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
|
||||
message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
|
||||
endif ()
|
||||
|
||||
if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
|
||||
set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
|
||||
message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the PICO SDK")
|
||||
set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of PICO SDK from git if not otherwise locatable")
|
||||
set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
|
||||
|
||||
if (NOT PICO_SDK_PATH)
|
||||
if (PICO_SDK_FETCH_FROM_GIT)
|
||||
include(FetchContent)
|
||||
set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
|
||||
if (PICO_SDK_FETCH_FROM_GIT_PATH)
|
||||
get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
|
||||
endif ()
|
||||
FetchContent_Declare(
|
||||
pico_sdk
|
||||
GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
|
||||
GIT_TAG master
|
||||
)
|
||||
if (NOT pico_sdk)
|
||||
message("Downloading PICO SDK")
|
||||
FetchContent_Populate(pico_sdk)
|
||||
set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
|
||||
endif ()
|
||||
set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
|
||||
else ()
|
||||
message(FATAL_ERROR
|
||||
"PICO SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
|
||||
)
|
||||
endif ()
|
||||
endif ()
|
||||
|
||||
get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
|
||||
if (NOT EXISTS ${PICO_SDK_PATH})
|
||||
message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
|
||||
if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
|
||||
message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the PICO SDK")
|
||||
endif ()
|
||||
|
||||
set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the PICO SDK" FORCE)
|
||||
|
||||
include(${PICO_SDK_INIT_CMAKE_FILE})
|
||||
Ładowanie…
Reference in New Issue