kopia lustrzana https://github.com/RPiks/pico-hf-oscillator
134 wiersze
4.6 KiB
Plaintext
134 wiersze
4.6 KiB
Plaintext
///////////////////////////////////////////////////////////////////////////////
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//
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// Roman Piksaykin [piksaykin@gmail.com], R2BDY
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// https://www.qrz.com/db/r2bdy
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//
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///////////////////////////////////////////////////////////////////////////////
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//
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//
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// dco2.pio - Digital controlled radio freq oscillator based on PIO.
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//
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//
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// DESCRIPTION
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//
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// The oscillator provides precise generation of any frequency ranging
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// from 1 Hz to 33.333 MHz with tenth's of millihertz resolution (please note that
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// this is relative resolution owing to the fact that the absolute accuracy of
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// onboard crystal of pi pico is limited; the absoulte accuracy can be provided
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// when using GPS reference option included).
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// The DCO uses phase locked loop principle programmed in C and PIO asm.
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// The DCO does *NOT* use any floating point operations - all time-critical
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// instructions run in 1 CPU cycle.
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// Currently the upper freq. limit is about 33.333 MHz and it is achieved only
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// using pi pico overclocking to 270 MHz.
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// Owing to the meager frequency step, it is possible to use 3, 5, or 7th
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// harmonics of generated frequency. Such solution completely cover all HF and
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// a portion of VHF band up to about 233 MHz.
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// Unfortunately due to pure digital freq.synthesis principle the jitter may
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// be a problem on higher frequencies. You should assess the quality of generated
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// signal if you want to emit a noticeable power.
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// This is an experimental project of amateur radio class and it is devised
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// by me on the free will base in order to experiment with QRP narrowband
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// digital modes.
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// I appreciate any thoughts or comments on that matter.
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//
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// PLATFORM
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// Raspberry Pi pico.
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//
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// REVISION HISTORY
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//
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// Rev 0.1 05 Nov 2023 Initial release
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// Rev 0.2 18 Nov 2023
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// Rev 1.0 10 Dec 2023 Improved frequency range (to ~33.333 MHz).
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//
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// PROJECT PAGE
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// https://github.com/RPiks/pico-hf-oscillator
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//
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// LICENCE
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// MIT License (http://www.opensource.org/licenses/mit-license.php)
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//
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// Copyright (c) 2023 by Roman Piksaykin
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//
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// Permission is hereby granted, free of charge,to any person obtaining a copy
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// of this software and associated documentation files (the Software), to deal
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// in the Software without restriction,including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY,WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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///////////////////////////////////////////////////////////////////////////////
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.program dco
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.wrap_target
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out y, 32
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mov x, y
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LOOP0:
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jmp x-- LOOP0
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set pins, 1
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mov x, y [1]
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LOOP1:
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jmp x-- LOOP1
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set pins, 0
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mov x, y [1]
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LOOP2:
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jmp x-- LOOP2
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set pins, 1
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mov x, y [1]
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LOOP3:
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jmp x-- LOOP3
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set pins, 0
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.wrap
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% c-sdk {
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#define PIOASM_DELAY_CYCLES 4
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static inline void dco_program_init(PIO pio, uint sm, uint offset, uint pin)
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{
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pio_sm_config c = dco_program_get_default_config(offset);
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sm_config_set_out_shift(&c, true, true, 32); // Autopull.
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sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
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sm_config_set_out_pins(&c, pin, 1);
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pio_gpio_init(pio, pin);
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pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
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sm_config_set_clkdiv_int_frac(&c, 1u, 0u);
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pio_sm_init(pio, sm, offset, &c);
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pio_sm_set_enabled(pio, sm, true);
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}
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//
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static inline void dco_program_puts(PIO pio, uint sm, const uint32_t *s)
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{
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pio_sm_put_blocking(pio, sm, s[0]);
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pio_sm_put_blocking(pio, sm, s[1]);
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pio_sm_put_blocking(pio, sm, s[2]);
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pio_sm_put_blocking(pio, sm, s[3]);
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pio_sm_put_blocking(pio, sm, s[4]);
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pio_sm_put_blocking(pio, sm, s[5]);
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pio_sm_put_blocking(pio, sm, s[6]);
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pio_sm_put_blocking(pio, sm, s[7]);
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}
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static inline void dco_program_puts1w(PIO pio, uint sm, const uint32_t val)
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{
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pio_sm_put_blocking(pio, sm, val);
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}
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%}
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