117 lines
3.7 KiB
C
117 lines
3.7 KiB
C
/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
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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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#include "common-hal/nativeio/AnalogIn.h"
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#include <string.h>
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#include "py/gc.h"
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#include "py/nlr.h"
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#include "py/runtime.h"
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#include "py/binary.h"
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#include "py/mphal.h"
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#include "shared-bindings/nativeio/AnalogIn.h"
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#include "asf/sam0/drivers/adc/adc.h"
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#include "samd21_pins.h"
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// Number of active ADC channels.
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volatile uint8_t active_channel_count;
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struct adc_module *adc_instance = NULL;
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void common_hal_nativeio_analogin_construct(nativeio_analogin_obj_t* self,
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const mcu_pin_obj_t *pin) {
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if (!pin->has_adc) {
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// No ADC function on that pin
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nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Pin does not have ADC capabilities"));
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}
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self->pin = pin;
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if (adc_instance == NULL) {
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struct adc_config config_adc;
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adc_get_config_defaults(&config_adc);
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config_adc.reference = ADC_REFERENCE_INTVCC1;
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config_adc.gain_factor = ADC_GAIN_FACTOR_DIV2;
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config_adc.positive_input = self->pin->adc_input;
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config_adc.resolution = ADC_RESOLUTION_16BIT;
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config_adc.clock_prescaler = ADC_CLOCK_PRESCALER_DIV128;
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// Allocate the instance on the heap so we only use the memory when we
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// need it.
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adc_instance = gc_alloc(sizeof(struct adc_module), false);
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adc_init(adc_instance, ADC, &config_adc);
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}
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self->adc_instance = adc_instance;
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active_channel_count++;
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}
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void common_hal_nativeio_analogin_deinit(nativeio_analogin_obj_t *self) {
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active_channel_count--;
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if (active_channel_count == 0) {
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adc_reset(adc_instance);
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gc_free(adc_instance);
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// Set our reference to NULL so the GC doesn't mistakenly see the
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// pointer in memory.
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adc_instance = NULL;
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}
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reset_pin(self->pin->pin);
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}
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void analogin_reset() {
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if (adc_instance != NULL) {
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adc_reset(adc_instance);
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adc_instance = NULL;
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}
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active_channel_count = 0;
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}
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uint16_t common_hal_nativeio_analogin_get_value(nativeio_analogin_obj_t *self) {
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adc_set_positive_input(adc_instance, self->pin->adc_input);
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adc_enable(adc_instance);
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adc_start_conversion(adc_instance);
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uint16_t data;
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enum status_code status = adc_read(adc_instance, &data);
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while (status == STATUS_BUSY) {
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status = adc_read(adc_instance, &data);
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}
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if (status == STATUS_ERR_OVERFLOW) {
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// TODO(tannewt): Throw an error.
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}
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adc_disable(adc_instance);
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return data;
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}
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float common_hal_nativeio_analogin_get_reference_voltage(nativeio_analogin_obj_t *self) {
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return 3.3f;
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}
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