35 lines
1.6 KiB
C
35 lines
1.6 KiB
C
#include "thermistor_driver.h"
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#include "watch.h"
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#include "watch_utility.h"
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void thermistor_driver_enable() {
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// Enable the ADC peripheral, which we'll use to read the thermistor value.
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watch_enable_adc();
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// Enable analog circuitry on the sense pin, which is tied to the thermistor resistor divider.
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watch_enable_analog_input(THERMISTOR_SENSE_PIN);
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// Enable digital output on the enable pin, which is the power to the thermistor circuit.
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watch_enable_digital_output(THERMISTOR_ENABLE_PIN);
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// and make sure it's off.
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watch_set_pin_level(THERMISTOR_ENABLE_PIN, !THERMISTOR_ENABLE_VALUE);
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}
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void thermistor_driver_disable() {
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// Disable the ADC peripheral.
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watch_disable_adc();
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// Disable analog circuitry on the sense pin to save power.
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watch_disable_analog_input(THERMISTOR_SENSE_PIN);
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// Disable the enable pin's output circuitry.
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watch_disable_digital_output(THERMISTOR_ENABLE_PIN);
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}
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float thermistor_driver_get_temperature() {
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// set the enable pin to the level that powers the thermistor circuit.
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watch_set_pin_level(THERMISTOR_ENABLE_PIN, THERMISTOR_ENABLE_VALUE);
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// get the sense pin level
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uint16_t value = watch_get_analog_pin_level(THERMISTOR_SENSE_PIN);
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// and then set the enable pin to the opposite value to power down the thermistor circuit.
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watch_set_pin_level(THERMISTOR_ENABLE_PIN, !THERMISTOR_ENABLE_VALUE);
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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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}
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