WIP phototransistor stuff

watch-library/shared/driver/phototransistor_driver.c

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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 "phototransistor_driver.h"
+#include "watch.h"
+#include "watch_utility.h"
+
+void phototransistor_driver_enable(void) {
+    // Enable the ADC peripheral, which we'll use to read the phototransistor value.
+    watch_enable_adc();
+    // Enable analog circuitry on the sense pin, which is tied to the phototransistor's base.
+    watch_enable_analog_input(PHOTOTRANSISTOR_SENSE_PIN);
+    // Enable digital output on the enable pin, which is the power to the phototransistor circuit.
+    watch_enable_digital_output(PHOTOTRANSISTOR_ENABLE_PIN);
+    // and make sure it's off.
+    // watch_set_pin_level(PHOTOTRANSISTOR_ENABLE_PIN, !PHOTOTRANSISTOR_ENABLE_VALUE);
+    watch_set_pin_level(PHOTOTRANSISTOR_ENABLE_PIN, PHOTOTRANSISTOR_ENABLE_VALUE);
+}
+
+void phototransistor_driver_disable(void) {
+    // Disable the ADC peripheral.
+    watch_disable_adc();
+    // Disable analog circuitry on the sense pin to save power.
+    watch_disable_analog_input(PHOTOTRANSISTOR_SENSE_PIN);
+    // Disable the enable pin's output circuitry.
+    watch_disable_digital_output(PHOTOTRANSISTOR_ENABLE_PIN);
+}
+
+uint16_t phototransistor_driver_get_light_level(void) {
+    // set the enable pin to the level that powers the phototransistor circuit.
+    // watch_set_pin_level(PHOTOTRANSISTOR_ENABLE_PIN, PHOTOTRANSISTOR_ENABLE_VALUE);
+    // get the sense pin level
+    uint16_t value = watch_get_analog_pin_level(PHOTOTRANSISTOR_SENSE_PIN);
+    // and then set the enable pin to the opposite value to power down the phototransistor circuit.
+    // watch_set_pin_level(PHOTOTRANSISTOR_ENABLE_PIN, !PHOTOTRANSISTOR_ENABLE_VALUE);
+
+    return value;
+}

watch-library/shared/driver/phototransistor_driver.h

@@ -0,0 +1,39 @@
+/*
+ * 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 <stdint.h>
+
+#ifndef PHOTOTRANSISTOR_DRIVER_H_
+#define PHOTOTRANSISTOR_DRIVER_H_
+
+#define PHOTOTRANSISTOR_SENSE_PIN (A4)
+#define PHOTOTRANSISTOR_ENABLE_PIN (A0)
+#define PHOTOTRANSISTOR_ENABLE_VALUE (true)
+#define PHOTOTRANSISTOR_SERIES_RESISTANCE (1000.0)
+
+void phototransistor_driver_enable(void);
+void phototransistor_driver_disable(void);
+uint16_t phototransistor_driver_get_light_level(void);
+
+#endif // PHOTOTRANSISTOR_DRIVER_H_