From 1ebee8e2a341ae323565015c3d64aace7bc87f9d Mon Sep 17 00:00:00 2001
From: Alex Wulff <alex@coniferapps.com>
Date: Fri, 29 Jan 2021 15:34:23 -0500
Subject: [PATCH] Removed one file

---
 adc_fft/backup2.c | 123 ----------------------------------------------
 1 file changed, 123 deletions(-)
 delete mode 100644 adc_fft/backup2.c

diff --git a/adc_fft/backup2.c b/adc_fft/backup2.c
deleted file mode 100644
index fa4f15d..0000000
--- a/adc_fft/backup2.c
+++ /dev/null
@@ -1,123 +0,0 @@
-// 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 <math.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 960
-#define FSAMP 50000
-
-// Channel 0 is GPIO26
-#define CAPTURE_CHANNEL 0
-#define LED_PIN 25
-#define NSAMP 5000
-
-// constants
-#define PI2 6.2831852
-
-// globals
-dma_channel_config cfg;
-uint dma_chan;
-float freqs[NSAMP];
-
-void setup();
-void sample(uint8_t *capture_buf);
-void do_dft(float *in, float *out_re, float *out_im);
-
-int main() {
-  setup();
-  
-  uint8_t cap_buf[NSAMP];
-  float ft_in[NSAMP];
-  float ft_out_re[NSAMP];
-  float ft_out_im[NSAMP];
-  
-  while (1) {
-    // get NSAMP samples at FSAMP
-    sample(cap_buf);
-    // fill fourier transform input
-    for (int i=0;i<NSAMP;i++) {ft_in[i]=(float)cap_buf[i];}
-    // perform fourier transform
-    do_dft(ft_in, ft_out_re, ft_out_im);
-    printf("Sampled!\n");
-  }
-}
-
-void do_dft(float *in, float *out_re, float *out_im) {
-  for (int i = 0; i < NSAMP; i++) {
-    printf("%f | %f | %f\n",in[i],out_re[i],out_im[i]);
-    //out_re[i] = 0; out_im[i] = 0;
-    for (int j = 0; j < NSAMP; j++) {
-      //out_re[i] += in[j]*sin(PI2*i*j/NSAMP);
-      //out_im[i] -= in[j]*cos(PI2*i*j/NSAMP);
-    }
-  }
-}
-
-void sample(uint8_t *capture_buf) {
-  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);
-}
-
-void setup() {
-  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
-  dma_chan = dma_claim_unused_channel(true);
-  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);
-
-  // 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;}
-}