Reinit ADC completely on each call to AnalogIn.value.
This commit is contained in:
parent
cfd1809b2b
commit
8f3be0a037
@ -38,13 +38,6 @@
|
|||||||
#include "asf/sam0/drivers/adc/adc.h"
|
#include "asf/sam0/drivers/adc/adc.h"
|
||||||
#include "samd21_pins.h"
|
#include "samd21_pins.h"
|
||||||
|
|
||||||
// Number of active ADC channels.
|
|
||||||
volatile uint8_t active_channel_count;
|
|
||||||
|
|
||||||
// Shared between all the instances. Allocated only when needed.
|
|
||||||
struct adc_module *adc_instance = NULL;
|
|
||||||
struct adc_config *config_adc = NULL;
|
|
||||||
|
|
||||||
void common_hal_analogio_analogin_construct(analogio_analogin_obj_t* self,
|
void common_hal_analogio_analogin_construct(analogio_analogin_obj_t* self,
|
||||||
const mcu_pin_obj_t *pin) {
|
const mcu_pin_obj_t *pin) {
|
||||||
if (!pin->has_adc) {
|
if (!pin->has_adc) {
|
||||||
@ -54,27 +47,6 @@ void common_hal_analogio_analogin_construct(analogio_analogin_obj_t* self,
|
|||||||
claim_pin(pin);
|
claim_pin(pin);
|
||||||
|
|
||||||
self->pin = pin;
|
self->pin = pin;
|
||||||
|
|
||||||
if (adc_instance == NULL) {
|
|
||||||
// Allocate strucs on the heap so we only use the memory when we
|
|
||||||
// need it.
|
|
||||||
adc_instance = gc_alloc(sizeof(struct adc_module), false);
|
|
||||||
config_adc = gc_alloc(sizeof(struct adc_config), false);
|
|
||||||
|
|
||||||
adc_get_config_defaults(config_adc);
|
|
||||||
|
|
||||||
config_adc->reference = ADC_REFERENCE_INTVCC1;
|
|
||||||
config_adc->gain_factor = ADC_GAIN_FACTOR_DIV2;
|
|
||||||
config_adc->positive_input = self->pin->adc_input;
|
|
||||||
config_adc->resolution = ADC_RESOLUTION_16BIT;
|
|
||||||
config_adc->clock_prescaler = ADC_CLOCK_PRESCALER_DIV128;
|
|
||||||
|
|
||||||
adc_init(adc_instance, ADC, config_adc);
|
|
||||||
}
|
|
||||||
|
|
||||||
self->adc_instance = adc_instance;
|
|
||||||
self->config_adc = config_adc;
|
|
||||||
active_channel_count++;
|
|
||||||
}
|
}
|
||||||
|
|
||||||
bool common_hal_analogio_analogin_deinited(analogio_analogin_obj_t *self) {
|
bool common_hal_analogio_analogin_deinited(analogio_analogin_obj_t *self) {
|
||||||
@ -85,36 +57,30 @@ void common_hal_analogio_analogin_deinit(analogio_analogin_obj_t *self) {
|
|||||||
if (common_hal_analogio_analogin_deinited(self)) {
|
if (common_hal_analogio_analogin_deinited(self)) {
|
||||||
return;
|
return;
|
||||||
}
|
}
|
||||||
active_channel_count--;
|
|
||||||
if (active_channel_count == 0) {
|
|
||||||
adc_reset(adc_instance);
|
|
||||||
gc_free(adc_instance);
|
|
||||||
gc_free(config_adc);
|
|
||||||
// Set our references to NULL so the GC doesn't mistakenly see the
|
|
||||||
// pointers in memory.
|
|
||||||
adc_instance = NULL;
|
|
||||||
config_adc = NULL;
|
|
||||||
}
|
|
||||||
reset_pin(self->pin->pin);
|
reset_pin(self->pin->pin);
|
||||||
self->pin = mp_const_none;
|
self->pin = mp_const_none;
|
||||||
}
|
}
|
||||||
|
|
||||||
void analogin_reset() {
|
void analogin_reset() {
|
||||||
if (adc_instance != NULL) {
|
|
||||||
adc_reset(adc_instance);
|
|
||||||
adc_instance = NULL;
|
|
||||||
}
|
|
||||||
active_channel_count = 0;
|
|
||||||
}
|
}
|
||||||
|
|
||||||
uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
|
uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
|
||||||
// Something else might have used the ADC in a different way,
|
// Something else might have used the ADC in a different way,
|
||||||
// so we have to completely re-initialize it.
|
// so we completely re-initialize it.
|
||||||
// ADC must have been disabled before adc_init() is called.
|
|
||||||
adc_init(adc_instance, ADC, config_adc);
|
|
||||||
config_adc->positive_input = self->pin->adc_input;
|
|
||||||
|
|
||||||
adc_enable(adc_instance);
|
struct adc_config config_adc;
|
||||||
|
adc_get_config_defaults(&config_adc);
|
||||||
|
|
||||||
|
config_adc.reference = ADC_REFERENCE_INTVCC1;
|
||||||
|
config_adc.gain_factor = ADC_GAIN_FACTOR_DIV2;
|
||||||
|
config_adc.positive_input = self->pin->adc_input;
|
||||||
|
config_adc.resolution = ADC_RESOLUTION_16BIT;
|
||||||
|
config_adc.clock_prescaler = ADC_CLOCK_PRESCALER_DIV128;
|
||||||
|
|
||||||
|
struct adc_module adc_instance;
|
||||||
|
// ADC must have been disabled before adc_init() is called.
|
||||||
|
adc_init(&adc_instance, ADC, &config_adc);
|
||||||
|
adc_enable(&adc_instance);
|
||||||
|
|
||||||
// Read twice and discard first result, as recommended in section 14 of
|
// Read twice and discard first result, as recommended in section 14 of
|
||||||
// http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf
|
// http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf
|
||||||
@ -125,23 +91,23 @@ uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
|
|||||||
uint16_t data;
|
uint16_t data;
|
||||||
enum status_code status;
|
enum status_code status;
|
||||||
|
|
||||||
adc_start_conversion(adc_instance);
|
adc_start_conversion(&adc_instance);
|
||||||
do {
|
do {
|
||||||
status = adc_read(adc_instance, &data);
|
status = adc_read(&adc_instance, &data);
|
||||||
} while (status == STATUS_BUSY);
|
} while (status == STATUS_BUSY);
|
||||||
if (status == STATUS_ERR_OVERFLOW) {
|
if (status == STATUS_ERR_OVERFLOW) {
|
||||||
// TODO(tannewt): Throw an error.
|
mp_raise_RuntimeError("ADC result overwritten before reading");
|
||||||
}
|
}
|
||||||
|
|
||||||
adc_start_conversion(adc_instance);
|
adc_start_conversion(&adc_instance);
|
||||||
do {
|
do {
|
||||||
status = adc_read(adc_instance, &data);
|
status = adc_read(&adc_instance, &data);
|
||||||
} while (status == STATUS_BUSY);
|
} while (status == STATUS_BUSY);
|
||||||
if (status == STATUS_ERR_OVERFLOW) {
|
if (status == STATUS_ERR_OVERFLOW) {
|
||||||
// TODO(tannewt): Throw an error.
|
mp_raise_RuntimeError("ADC result overwritten before reading");
|
||||||
}
|
}
|
||||||
|
|
||||||
adc_disable(adc_instance);
|
adc_disable(&adc_instance);
|
||||||
return data;
|
return data;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -41,8 +41,6 @@
|
|||||||
typedef struct {
|
typedef struct {
|
||||||
mp_obj_base_t base;
|
mp_obj_base_t base;
|
||||||
const mcu_pin_obj_t * pin;
|
const mcu_pin_obj_t * pin;
|
||||||
struct adc_module * adc_instance;
|
|
||||||
struct adc_config * config_adc;
|
|
||||||
} analogio_analogin_obj_t;
|
} analogio_analogin_obj_t;
|
||||||
|
|
||||||
void analogin_reset(void);
|
void analogin_reset(void);
|
||||||
|
@ -203,6 +203,7 @@ void reset_samd21(void) {
|
|||||||
analogin_reset();
|
analogin_reset();
|
||||||
|
|
||||||
|
|
||||||
|
// TODO: move this to analogout_reset()
|
||||||
// Wait for the DAC to sync then reset.
|
// Wait for the DAC to sync then reset.
|
||||||
while (DAC->STATUS.reg & DAC_STATUS_SYNCBUSY) {}
|
while (DAC->STATUS.reg & DAC_STATUS_SYNCBUSY) {}
|
||||||
DAC->CTRLA.reg |= DAC_CTRLA_SWRST;
|
DAC->CTRLA.reg |= DAC_CTRLA_SWRST;
|
||||||
|
Loading…
x
Reference in New Issue
Block a user