-I../watch_faces/clock/ \
-I../watch_faces/settings/ \
-I../watch_faces/complications/ \
+ -I../watch_faces/thermistor/ \
# If you add any other source files you wish to compile, add them after ../app.c
# Note that you will need to add a backslash at the end of any line you wish to continue, i.e.
../watch_faces/settings/preferences_face.c \
../watch_faces/settings/set_time_face.c \
../watch_faces/complications/pulsometer_face.c \
+ ../watch_faces/thermistor/thermistor_driver.c \
+ ../watch_faces/thermistor/thermistor_readout_face.c \
# Leave this line at the bottom of the file; it has all the targets for making your project.
include $(TOP)/rules.mk
// TODO: none of this is implemented
typedef union {
struct {
- uint32_t reserved : 15;
- uint32_t clock_mode_24h : 1; // determines whether clock should use 12 or 24 hour mode.
+ uint32_t reserved : 14;
uint32_t button_should_sound : 1; // if true, pressing a button emits a sound.
uint32_t to_interval : 2; // an inactivity interval for asking the active face to resign.
uint32_t le_interval : 3; // 0 to disable low energy mode, or an inactivity interval for going into low energy mode.
uint32_t led_duration : 2; // how many seconds to shine the LED for (x2), or 0 to disable it.
uint32_t led_red_color : 4; // for general purpose illumination, the red LED value (0-15)
uint32_t led_green_color : 4; // for general purpose illumination, the green LED value (0-15)
+
+ // while Movement itself doesn't implement a clock or display units, it may make sense to include some
+ // global settings for watch faces to check. The 12/24 hour preference could inform a clock or a
+ // time-oriented complication like a sunrise/sunset timer, and a simple locale preference could tell an
+ // altimeter to display feet or meters as easily as it tells a thermometer to display degrees in F or C.
+ uint32_t clock_mode_24h : 1; // indicates whether clock should use 12 or 24 hour mode.
+ uint32_t use_imperial_units : 1; // indicates whether to use metric units (the default) or imperial.
} bit;
uint32_t value;
} movement_settings_t;
#include "preferences_face.h"
#include "set_time_face.h"
#include "pulsometer_face.h"
+#include "thermistor_readout_face.h"
const watch_face_t watch_faces[] = {
simple_clock_face,
--- /dev/null
+#include "thermistor_driver.h"
+#include "watch.h"
+
+#define THERMISTOR_B_COEFFICIENT (3950.0)
+#define THERMISTOR_NOMINAL_TEMPERATURE (25.0)
+#define THERMISTOR_NOMINAL_RESISTANCE (10000.0)
+#define THERMISTOR_SERIES_RESISTANCE (10000.0)
+
+// TODO: we really need a math library.
+uint32_t msb(uint32_t v);
+double ln(double y);
+
+void thermistor_driver_enable() {
+ // Enable the ADC peripheral, which we'll use to read the thermistor value.
+ watch_enable_adc();
+ // Enable analog circuitry on pin A1, which is tied to the thermistor resistor divider.
+ watch_enable_analog_input(A1);
+ // Enable digital output on A0, which is the power to the thermistor circuit.
+ watch_enable_digital_output(A0);
+}
+
+void thermistor_driver_disable() {
+ // Enable the ADC peripheral, which we'll use to read the thermistor value.
+ watch_disable_adc();
+ // Disable analog circuitry on pin A1 to save power.
+ watch_disable_analog_input(A1);
+ // Disable A0's output circuitry.
+ watch_disable_digital_output(A0);
+}
+
+float thermistor_driver_get_temperature() {
+ // set A0 high to power the thermistor circuit.
+ watch_set_pin_level(A0, true);
+ // get the pin level
+ uint16_t val = watch_get_analog_pin_level(A1);
+ // and then set A0 low to power down the thermistor circuit.
+ watch_set_pin_level(A0, false);
+
+ double reading = (double)val;
+ reading = (1023.0 * THERMISTOR_SERIES_RESISTANCE) / (reading / 64.0);
+ reading -= THERMISTOR_SERIES_RESISTANCE;
+ reading = reading / THERMISTOR_NOMINAL_RESISTANCE;
+ reading = ln(reading);
+ reading /= THERMISTOR_B_COEFFICIENT;
+ reading += 1.0 / (THERMISTOR_NOMINAL_TEMPERATURE + 273.15);
+ reading = 1.0 / reading;
+ reading -= 273.15;
+
+ return reading;
+}
+
+uint32_t msb(uint32_t v) {
+ static const int pos[32] = {0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9};
+ v |= v >> 1;
+ v |= v >> 2;
+ v |= v >> 4;
+ v |= v >> 8;
+ v |= v >> 16;
+ v = (v >> 1) + 1;
+ return pos[(v * 0x077CB531UL) >> 27];
+}
+
+double ln(double y) {
+ int log2;
+ double divisor, x, result;
+
+ log2 = msb((int)y); // See: https://stackoverflow.com/a/4970859/6630230
+ divisor = (double)(1 << log2);
+ x = y / divisor; // normalized value between [1.0, 2.0]
+
+ result = -1.7417939 + (2.8212026 + (-1.4699568 + (0.44717955 - 0.056570851 * x) * x) * x) * x;
+ result += ((double)log2) * 0.69314718; // ln(2) = 0.69314718
+
+ return result;
+}
+
--- /dev/null
+#ifndef THERMISTOR_DRIVER_H_
+#define THERMISTOR_DRIVER_H_
+
+// NOTE: This implementation is specific to one prototype sensor board, OSO-MISC-21-009, but both
+// the sensor board design and this implementation are likely to change. Thermistor functionality
+// may even end up being baked into the Sensor Watch library. This is all by way of saying this
+// code is very temporary and the thermistor screens will likely get a rewrite in the future.
+
+void thermistor_driver_enable();
+void thermistor_driver_disable();
+float thermistor_driver_get_temperature();
+
+#endif // THERMISTOR_DRIVER_H_
--- /dev/null
+#include <stdlib.h>
+#include <string.h>
+#include "thermistor_readout_face.h"
+#include "thermistor_driver.h"
+#include "watch.h"
+
+void _thermistor_readout_face_update_display(bool in_fahrenheit) {
+ float temperature_c = thermistor_driver_get_temperature();
+ char buf[14];
+ if (in_fahrenheit) {
+ sprintf(buf, "%4.1f#F", temperature_c * 1.8 + 32.0);
+ } else {
+ sprintf(buf, "%4.1f#C", temperature_c);
+ }
+ watch_display_string(buf, 4);
+}
+
+void thermistor_readout_face_setup(movement_settings_t *settings, void ** context_ptr) {
+ (void) settings;
+ (void) context_ptr;
+}
+
+void thermistor_readout_face_activate(movement_settings_t *settings, void *context) {
+ (void) settings;
+ (void) context;
+ watch_display_string("TE", 0);
+ thermistor_driver_enable();
+}
+
+bool thermistor_readout_face_loop(movement_event_t event, movement_settings_t *settings, void *context) {
+ (void) context;
+ watch_date_time date_time = watch_rtc_get_date_time();
+ switch (event.event_type) {
+ case EVENT_MODE_BUTTON_UP:
+ movement_move_to_next_face();
+ break;
+ case EVENT_LIGHT_BUTTON_DOWN:
+ movement_illuminate_led();
+ break;
+ case EVENT_ALARM_BUTTON_UP:
+ settings->bit.use_imperial_units = !settings->bit.use_imperial_units;
+ _thermistor_readout_face_update_display(settings->bit.use_imperial_units);
+ break;
+ case EVENT_ACTIVATE:
+ // force a measurement to be taken immediately.
+ date_time.unit.second = 0;
+ // fall through
+ case EVENT_TICK:
+ if (date_time.unit.second % 5 == 4) {
+ // Not 100% on this, but I like the idea of using the signal indicator to indicate that we're sensing data.
+ // In this case we turn the indicator on a second before the reading is taken, and clear it when we're done.
+ // In reality the measurement takes a fraction of a second, but this is just to show something is happening.
+ watch_set_indicator(WATCH_INDICATOR_SIGNAL);
+ } else if (date_time.unit.second % 5 == 0) {
+ _thermistor_readout_face_update_display(settings->bit.use_imperial_units);
+ watch_clear_indicator(WATCH_INDICATOR_SIGNAL);
+ }
+ break;
+ case EVENT_TIMEOUT:
+ movement_move_to_face(0);
+ break;
+ default:
+ break;
+ }
+
+ return true;
+}
+
+void thermistor_readout_face_resign(movement_settings_t *settings, void *context) {
+ (void) settings;
+ (void) context;
+ thermistor_driver_disable();
+}
--- /dev/null
+#ifndef THERMISTOR_FACE_H_
+#define THERMISTOR_FACE_H_
+
+#include "movement.h"
+
+void thermistor_readout_face_setup(movement_settings_t *settings, void ** context_ptr);
+void thermistor_readout_face_activate(movement_settings_t *settings, void *context);
+bool thermistor_readout_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void thermistor_readout_face_resign(movement_settings_t *settings, void *context);
+
+static const watch_face_t thermistor_readout_face = {
+ thermistor_readout_face_setup,
+ thermistor_readout_face_activate,
+ thermistor_readout_face_loop,
+ thermistor_readout_face_resign,
+ NULL
+};
+
+#endif // THERMISTOR_FACE_H_
\ No newline at end of file
projects / sensor-watch.git / commitdiff