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/*
* MIT License
*
* Copyright (c) 2022 Joey Castillo
*
* 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 "thermistor_driver.h"
#include "watch.h"
#include "watch_utility.h"
void thermistor_driver_enable(void) {
// Enable the ADC peripheral, which we'll use to read the thermistor value.
watch_enable_adc();
// Enable analog circuitry on the sense pin, which is tied to the thermistor resistor divider.
watch_enable_analog_input(THERMISTOR_SENSE_PIN);
// Enable digital output on the enable pin, which is the power to the thermistor circuit.
watch_enable_digital_output(THERMISTOR_ENABLE_PIN);
// and make sure it's off.
watch_set_pin_level(THERMISTOR_ENABLE_PIN, !THERMISTOR_ENABLE_VALUE);
}
void thermistor_driver_disable(void) {
// Disable the ADC peripheral.
watch_disable_adc();
// Disable analog circuitry on the sense pin to save power.
watch_disable_analog_input(THERMISTOR_SENSE_PIN);
// Disable the enable pin's output circuitry.
watch_disable_digital_output(THERMISTOR_ENABLE_PIN);
}
float thermistor_driver_get_temperature(void) {
// set the enable pin to the level that powers the thermistor circuit.
watch_set_pin_level(THERMISTOR_ENABLE_PIN, THERMISTOR_ENABLE_VALUE);
// get the sense pin level
uint16_t value = watch_get_analog_pin_level(THERMISTOR_SENSE_PIN);
// and then set the enable pin to the opposite value to power down the thermistor circuit.
watch_set_pin_level(THERMISTOR_ENABLE_PIN, !THERMISTOR_ENABLE_VALUE);
return watch_utility_thermistor_temperature(value, THERMISTOR_HIGH_SIDE, THERMISTOR_B_COEFFICIENT, THERMISTOR_NOMINAL_TEMPERATURE, THERMISTOR_NOMINAL_RESISTANCE, THERMISTOR_SERIES_RESISTANCE);
}
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