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Sample Rate Enhancements

This commit is contained in:
Lee Atkinson 2022-08-11 17:50:30 -04:00
parent e778112710
commit c3c1e307c4
5 changed files with 54 additions and 51 deletions
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5
locale/circuitpython.pot
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@ -3863,6 +3863,11 @@ msgstr ""
msgid "rsplit(None,n)"
msgstr ""
#: shared-bindings/analogio/AnalogFastIn.c
msgid "sample rate must be 1.0-500000.0 per second"
msgstr ""
#: shared-bindings/analogio/AnalogFastIn.c
#: shared-bindings/audiocore/RawSample.c
msgid ""
"sample_source buffer must be a bytearray or array of type 'h', 'H', 'b' or "

80
ports/raspberrypi/common-hal/analogio/AnalogFastIn.c
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@ -29,16 +29,12 @@
#include "shared-bindings/microcontroller/Pin.h"
#include "py/runtime.h"
#include "supervisor/shared/translate/translate.h"
#include "src/rp2_common/hardware_adc/include/hardware/adc.h"
#include "src/rp2_common/hardware_dma/include/hardware/dma.h"
// /sdk/src/rp2_common/hardware_dma/include/hardware/dma.h
// ports/raspberrypi/
// ports/raspberrypi/
#include "sdk/src/common/pico_stdlib/include/pico/stdlib.h"
#define ADC_FIRST_PIN_NUMBER 26
#define ADC_PIN_COUNT 4
// Channel 0 is GPIO26
@ -46,30 +42,7 @@
#define CAPTURE_DEPTH 1000
uint8_t capture_buf[CAPTURE_DEPTH];
// ADC unit8 or int8 ??? ---> unint16
//
// uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
// adc_select_input(self->pin->number - ADC_FIRST_PIN_NUMBER);
// uint16_t value = adc_read();
//
// // Stretch 12-bit ADC reading to 16-bit range
// return (value << 4) | (value >> 8);
// }
/*
typedef struct {
mp_obj_base_t base;
uint8_t number;
} mcu_pin_obj_t;
*/
// self->pin = pin;
// self->buffer = buffer;
// self->len = len;
// //self->bits_per_sample = bytes_per_sample * 8;
// self->samples_signed = samples_signed;
// self->sample_rate = sample_rate;
void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *self, const mcu_pin_obj_t *pin, uint8_t *buffer, uint32_t len, uint8_t bytes_per_sample, bool samples_signed, uint32_t sample_rate) {
void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *self, const mcu_pin_obj_t *pin, uint8_t *buffer, uint32_t len, uint8_t bytes_per_sample, bool samples_signed, mp_float_t sample_rate) {
// Set pin and channel
self->pin = pin;
@ -83,7 +56,6 @@ void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *sel
// checks on length here
// uint8_t bytes_per_sample
// Set sample rate
// self->bits_per_sample = bytes_per_sample * 8;
@ -102,7 +74,7 @@ void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *sel
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 // ??
false // Shift each sample to 8 bits when pushing to FIFO // ??
);
// Divisor of 0 -> full speed. Free-running capture with the divider is
@ -112,28 +84,28 @@ void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *sel
// continuously) or > 95 (take samples less frequently than 96 cycle
// intervals). This is all timed by the 48 MHz ADC clock.
// sample rate determines divisor, not zero.
adc_set_clkdiv(0);
adc_set_clkdiv(48000000.0 / self->sample_rate);
// 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);
self->dma_chan = dma_chan;
dma_channel_config cfg = dma_channel_get_default_config(dma_chan);
// Set Config
self->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);
channel_config_set_transfer_data_size(&(self->cfg), DMA_SIZE_16);
channel_config_set_read_increment(&(self->cfg), false);
channel_config_set_write_increment(&(self->cfg), true);
// Pace transfers based on availability of ADC samples
channel_config_set_dreq(&cfg, DREQ_ADC);
channel_config_set_dreq(&(self->cfg), DREQ_ADC);
dma_channel_configure(dma_chan, &cfg,
capture_buf, // dst
&adc_hw->fifo, // src
self->len, // CAPTURE_DEPTH, // transfer count
true // start immediately
);
// clear any previous activity
adc_fifo_drain();
adc_run(false);
}
@ -146,8 +118,12 @@ void common_hal_analogio_analogfastin_deinit(analogio_analogfastin_obj_t *self)
return;
}
// Release ADC Pin
reset_pin_number(self->pin->number);
self->pin = NULL;
// Release DMA Channel
dma_channel_unclaim(self->dma_chan);
}
// ================================================================
@ -155,15 +131,31 @@ void common_hal_analogio_analogfastin_deinit(analogio_analogfastin_obj_t *self)
// make this a bool so that later we can perform integrity checking
// ================================================================
bool common_hal_analogio_analogfastin_capture(analogio_analogfastin_obj_t *self) {
// CONSIDER THESE ISSUES
// uint16_t value = adc_read();
// Stretch 12-bit ADC reading to 16-bit range
// return (value << 4) | (value >> 8);
uint32_t cdl = self->len / 2 - 1;
dma_channel_configure(self->dma_chan, &(self->cfg),
self->buffer, // dst
&adc_hw->fifo, // src
cdl, // CAPTURE_DEPTH, // transfer count
true // start immediately
);
// Start the ADC
adc_run(true);
// Once DMA finishes, stop any new conversions from starting, and clean up
// the FIFO in case the ADC was still mid-conversion.
dma_channel_wait_for_finish_blocking(self->dma_chan);
// printf("Capture finished\n");
// Clean up
adc_run(false);
adc_fifo_drain();
return true;
}

4
ports/raspberrypi/common-hal/analogio/AnalogFastIn.h
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@ -28,6 +28,7 @@
#define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_ANALOGIO_ANALOGFASTIN_H
#include "common-hal/microcontroller/Pin.h"
#include "src/rp2_common/hardware_dma/include/hardware/dma.h"
#include "py/obj.h"
@ -39,9 +40,10 @@ typedef struct {
uint32_t len;
uint8_t bytes_per_sample;
bool samples_signed;
uint32_t sample_rate;
mp_float_t sample_rate;
uint8_t chan;
uint dma_chan;
dma_channel_config cfg;
// data_size = DMA_SIZE_8; // - default DMA_SIZE_8
// data_size = DMA_SIZE_16; // - default DMA_SIZE_16
// Either 12 bits in 16 or 12 over 2 bytes or truncate 12 to 8 in 8

14
shared-bindings/analogio/AnalogFastIn.c
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@ -37,15 +37,18 @@
#include "shared-bindings/util.h"
// pin, buffer, rate
STATIC void validate_rate(mp_float_t rate) {
if (rate < (mp_float_t)1.0f || rate > (mp_float_t)500000.0f) {
mp_raise_ValueError(translate("sample rate must be 1.0-500000.0 per second"));
}
}
STATIC mp_obj_t analogio_analogfastin_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
enum { ARG_pin, ARG_buffer, ARG_sample_rate };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_pin, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_pin, MP_ARG_OBJ | MP_ARG_REQUIRED },
{ MP_QSTR_buffer, MP_ARG_OBJ | MP_ARG_REQUIRED },
{ MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 8000} },
{ MP_QSTR_sample_rate, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_obj = MP_OBJ_NEW_SMALL_INT(1)} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
@ -69,7 +72,8 @@ STATIC mp_obj_t analogio_analogfastin_make_new(const mp_obj_type_t *type, size_t
}
// Validate sample rate here
uint32_t sample_rate = args[ARG_sample_rate].u_int;
mp_float_t sample_rate = mp_obj_get_float(args[ARG_sample_rate].u_obj);
validate_rate(sample_rate);
// Create local object
analogio_analogfastin_obj_t *self = m_new_obj(analogio_analogfastin_obj_t);

2
shared-bindings/analogio/AnalogFastIn.h
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@ -32,7 +32,7 @@
extern const mp_obj_type_t analogio_analogfastin_type;
void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *self, const mcu_pin_obj_t *pin, uint8_t *buffer, uint32_t len, uint8_t bytes_per_sample, bool samples_signed, uint32_t sample_rate);
void common_hal_analogio_analogfastin_construct(analogio_analogfastin_obj_t *self, const mcu_pin_obj_t *pin, uint8_t *buffer, uint32_t len, uint8_t bytes_per_sample, bool samples_signed, mp_float_t sample_rate);
void common_hal_analogio_analogfastin_deinit(analogio_analogfastin_obj_t *self);
bool common_hal_analogio_analogfastin_deinited(analogio_analogfastin_obj_t *self);
bool common_hal_analogio_analogfastin_capture(analogio_analogfastin_obj_t *self);