135 lines
4.6 KiB
C
135 lines
4.6 KiB
C
/*
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2019 Dan Halbert for Adafruit Industries
|
|
* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "common-hal/analogio/AnalogIn.h"
|
|
#include "shared-bindings/analogio/AnalogIn.h"
|
|
#include "py/runtime.h"
|
|
#include "supervisor/shared/translate.h"
|
|
|
|
#include "nrf_saadc.h"
|
|
#include "nrf_gpio.h"
|
|
|
|
#define CHANNEL_NO 0
|
|
|
|
void analogin_init(void) {
|
|
// Calibrate the ADC once, on startup.
|
|
nrf_saadc_enable(NRF_SAADC);
|
|
nrf_saadc_event_clear(NRF_SAADC, NRF_SAADC_EVENT_CALIBRATEDONE);
|
|
nrf_saadc_task_trigger(NRF_SAADC, NRF_SAADC_TASK_CALIBRATEOFFSET);
|
|
while (nrf_saadc_event_check(NRF_SAADC, NRF_SAADC_EVENT_CALIBRATEDONE) == 0) {
|
|
}
|
|
nrf_saadc_event_clear(NRF_SAADC, NRF_SAADC_EVENT_CALIBRATEDONE);
|
|
nrf_saadc_disable(NRF_SAADC);
|
|
}
|
|
|
|
void common_hal_analogio_analogin_construct(analogio_analogin_obj_t *self, const mcu_pin_obj_t *pin) {
|
|
if (pin->adc_channel == 0) {
|
|
mp_raise_ValueError(translate("Pin does not have ADC capabilities"));
|
|
}
|
|
|
|
nrf_gpio_cfg_default(pin->number);
|
|
|
|
claim_pin(pin);
|
|
self->pin = pin;
|
|
}
|
|
|
|
bool common_hal_analogio_analogin_deinited(analogio_analogin_obj_t *self) {
|
|
return self->pin == NULL;
|
|
}
|
|
|
|
void common_hal_analogio_analogin_deinit(analogio_analogin_obj_t *self) {
|
|
if (common_hal_analogio_analogin_deinited(self)) {
|
|
return;
|
|
}
|
|
|
|
nrf_gpio_cfg_default(self->pin->number);
|
|
|
|
reset_pin_number(self->pin->number);
|
|
self->pin = NULL;
|
|
}
|
|
|
|
uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
|
|
// Something else might have used the ADC in a different way,
|
|
// so we completely re-initialize it.
|
|
|
|
nrf_saadc_value_t value;
|
|
|
|
const nrf_saadc_channel_config_t config = {
|
|
.resistor_p = NRF_SAADC_RESISTOR_DISABLED,
|
|
.resistor_n = NRF_SAADC_RESISTOR_DISABLED,
|
|
.gain = NRF_SAADC_GAIN1_4,
|
|
.reference = NRF_SAADC_REFERENCE_VDD4,
|
|
.acq_time = NRF_SAADC_ACQTIME_3US,
|
|
.mode = NRF_SAADC_MODE_SINGLE_ENDED,
|
|
.burst = NRF_SAADC_BURST_DISABLED
|
|
};
|
|
|
|
nrf_saadc_resolution_set(NRF_SAADC, NRF_SAADC_RESOLUTION_14BIT);
|
|
nrf_saadc_oversample_set(NRF_SAADC, NRF_SAADC_OVERSAMPLE_DISABLED);
|
|
nrf_saadc_enable(NRF_SAADC);
|
|
|
|
for (uint32_t i = 0; i < SAADC_CH_NUM; i++) {
|
|
nrf_saadc_channel_input_set(NRF_SAADC, i, NRF_SAADC_INPUT_DISABLED, NRF_SAADC_INPUT_DISABLED);
|
|
}
|
|
|
|
nrf_saadc_channel_init(NRF_SAADC, CHANNEL_NO, &config);
|
|
nrf_saadc_channel_input_set(NRF_SAADC, CHANNEL_NO, self->pin->adc_channel, self->pin->adc_channel);
|
|
nrf_saadc_buffer_init(NRF_SAADC, &value, 1);
|
|
|
|
nrf_saadc_task_trigger(NRF_SAADC, NRF_SAADC_TASK_START);
|
|
while (nrf_saadc_event_check(NRF_SAADC, NRF_SAADC_EVENT_STARTED) == 0) {
|
|
;
|
|
}
|
|
nrf_saadc_event_clear(NRF_SAADC, NRF_SAADC_EVENT_STARTED);
|
|
|
|
nrf_saadc_task_trigger(NRF_SAADC, NRF_SAADC_TASK_SAMPLE);
|
|
while (nrf_saadc_event_check(NRF_SAADC, NRF_SAADC_EVENT_END) == 0) {
|
|
;
|
|
}
|
|
nrf_saadc_event_clear(NRF_SAADC, NRF_SAADC_EVENT_END);
|
|
|
|
nrf_saadc_task_trigger(NRF_SAADC, NRF_SAADC_TASK_STOP);
|
|
while (nrf_saadc_event_check(NRF_SAADC, NRF_SAADC_EVENT_STOPPED) == 0) {
|
|
;
|
|
}
|
|
nrf_saadc_event_clear(NRF_SAADC, NRF_SAADC_EVENT_STOPPED);
|
|
|
|
nrf_saadc_disable(NRF_SAADC);
|
|
|
|
if (value < 0) {
|
|
value = 0;
|
|
}
|
|
|
|
// Map value to from 14 to 16 bits
|
|
return value << 2;
|
|
}
|
|
|
|
float common_hal_analogio_analogin_get_reference_voltage(analogio_analogin_obj_t *self) {
|
|
// The nominal VCC voltage
|
|
return 3.3f;
|
|
}
|