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comparison modulator.c @ 27:e1d8fe3e418a

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Run PIOs at 1x with delays and sync. Can now use a single trigger to set both DAC & ctrl. DAC [still] jitters against the ctrl though..
author Daniel O'Connor <darius@dons.net.au>
date Wed, 26 Feb 2025 11:03:59 +1030
parents 336f06fa6e47
children 600a394629e6
comparison
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26:336f06fa6e47 27:e1d8fe3e418a
360 printf("Unable to load DAC program\n"); 360 printf("Unable to load DAC program\n");
361 __breakpoint(); 361 __breakpoint();
362 } 362 }
363 dac_sm = pio_claim_unused_sm(pulse_pio, true); 363 dac_sm = pio_claim_unused_sm(pulse_pio, true);
364 // Data is GPIO7 to GPIO14, clock is GPIO15 364 // Data is GPIO7 to GPIO14, clock is GPIO15
365 // Clock divisor of 2 so it runs at 60MHz and 365 // Clock divisor of 1 but the PIO has delays so it runs at 60MHz
366 // generates a 30MHz clock 366 // and generates a 30MHz clock
367 dac_program_init(pulse_pio, dac_sm, dac_pio_sm_offset, DACOUT_GPIO, 2); 367 dac_program_init(pulse_pio, dac_sm, dac_pio_sm_offset, DACOUT_GPIO, 1);
368 368
369 // Configure a channel to write 32 bits at a time to PIO0 369 // Configure a channel to write 32 bits at a time to PIO0
370 // SM0's TX FIFO, paced by the data request signal from that peripheral. 370 // SM0's TX FIFO, paced by the data request signal from that peripheral.
371 dac_dma_chan = dma_claim_unused_channel(true); 371 dac_dma_chan = dma_claim_unused_channel(true);
372 dma_channel_config dac_dmac = dma_channel_get_default_config(dac_dma_chan); 372 dma_channel_config dac_dmac = dma_channel_get_default_config(dac_dma_chan);
396 if (ctrl_pio_sm_offset < 0) { 396 if (ctrl_pio_sm_offset < 0) {
397 printf("Unable to load ctrl program\n"); 397 printf("Unable to load ctrl program\n");
398 __breakpoint(); 398 __breakpoint();
399 } 399 }
400 ctrl_sm = pio_claim_unused_sm(pulse_pio, true); 400 ctrl_sm = pio_claim_unused_sm(pulse_pio, true);
401 ctrl_program_init(pulse_pio, ctrl_sm, ctrl_pio_sm_offset, CTRLOUT_GPIO, 2); 401 ctrl_program_init(pulse_pio, ctrl_sm, ctrl_pio_sm_offset, CTRLOUT_GPIO, 1);
402 402
403 // Configure a channel to write 32 bits at a time to PIO0 403 // Configure a channel to write 32 bits at a time to PIO0
404 // SM0's TX FIFO, paced by the data request signal from that peripheral. 404 // SM0's TX FIFO, paced by the data request signal from that peripheral.
405 ctrl_dma_chan = dma_claim_unused_channel(true); 405 ctrl_dma_chan = dma_claim_unused_channel(true);
406 dma_channel_config ctrl_dmac = dma_channel_get_default_config(ctrl_dma_chan); 406 dma_channel_config ctrl_dmac = dma_channel_get_default_config(ctrl_dma_chan);
425 if (trigger_pio_sm_offset < 0) { 425 if (trigger_pio_sm_offset < 0) {
426 printf("Unable to load trigger program\n"); 426 printf("Unable to load trigger program\n");
427 __breakpoint(); 427 __breakpoint();
428 } 428 }
429 uint trigger_sm = pio_claim_unused_sm(pulse_pio, true); 429 uint trigger_sm = pio_claim_unused_sm(pulse_pio, true);
430 trigger_program_init(pulse_pio, trigger_sm, trigger_pio_sm_offset, TRIGIN_GPIO, 2); 430 trigger_program_init(pulse_pio, trigger_sm, trigger_pio_sm_offset, TRIGIN_GPIO, 1);
431 #endif 431 #endif
432 432
433 // Start & sync all state machines
434 // This is necessary to avoid any jitter and to make the
435 // trigger sync work correctly
436 pio_enable_sm_mask_in_sync(pulse_pio,
437 1u << dac_sm |
438 1u << ctrl_sm |
439 #ifdef WITH_TRIGGER
440 1u << trigger_sm
441 #endif
442 );
433 // 443 //
434 // Setup PWM 444 // Setup PWM
435 // Used here to output a trigger which gets fed back into the trigger SM 445 // Used here to output a trigger which gets fed back into the trigger SM
436 // 446 //
437 // 120MHz / 250 = 480kHz base 447 // 120MHz / 250 = 480kHz base
438 // Maximum divisor is only 256 which limits the low end, 448 // Maximum divisor is only 256 which limits the low end,
439 // could further subdivide in the IRQ handler 449 // could further subdivide in the IRQ handler
440 pwm_config c = pwm_get_default_config(); 450 pwm_config c = pwm_get_default_config();
441 pwm_config_set_clkdiv_int(&c, 250); 451 pwm_config_set_clkdiv_int(&c, 250);
442 // 8Hz 452 // 80Hz
443 pwm_config_set_wrap(&c, 60000 - 1); 453 pwm_config_set_wrap(&c, 6000 - 1);
444 454
445 gpio_set_function(TRIGOUT_GPIO, GPIO_FUNC_PWM); 455 gpio_set_function(TRIGOUT_GPIO, GPIO_FUNC_PWM);
446 456
447 slice_num = pwm_gpio_to_slice_num(TRIGOUT_GPIO); 457 slice_num = pwm_gpio_to_slice_num(TRIGOUT_GPIO);
448 pwm_init(slice_num, &c, true); 458 pwm_init(slice_num, &c, true);