1 files changed, 37 insertions, 0 deletions
diff --git a/apps/Light Meter/tsl2591.c b/apps/Light Meter/tsl2591.c
new file mode 100644
index 00000000..96c53159
--- /dev/null
+++ b/apps/Light Meter/tsl2591.c
@@ -0,0 +1,37 @@
+#include "tsl2591.h"
+#include "watch_i2c.h"
+
+bool tsl2591_init() {
+    uint8_t device_id = watch_i2c_read8(TSL2591_ADDRESS, TSL2591_REGISTER_DEVICE_ID | TSL2591_COMMAND_BIT);
+    if (device_id != 0x50) return false;
+
+    tsl2591_set_gain(TSL2591_CONTROL_GAIN_LOW);
+    tsl2591_set_integration_time(TSL2591_CONTROL_INTEGRATIONTIME_100MS);
+    watch_i2c_write8(TSL2591_ADDRESS, TSL2591_REGISTER_ENABLE | TSL2591_COMMAND_BIT, TSL2591_ENABLE_POWERON | TSL2591_ENABLE_AEN);
+
+    return true;
+}
+
+void tsl2591_set_gain(TSL2591Control gain) {
+    uint8_t control = watch_i2c_read8(TSL2591_ADDRESS, TSL2591_REGISTER_CONTROL | TSL2591_COMMAND_BIT);
+    control &= 0b11001111;
+    control |= gain;
+    watch_i2c_write8(TSL2591_ADDRESS, TSL2591_REGISTER_CONTROL | TSL2591_COMMAND_BIT, control);
+}
+
+void tsl2591_set_integration_time(TSL2591Control integration_time) {
+    uint8_t control = watch_i2c_read8(TSL2591_ADDRESS, TSL2591_REGISTER_CONTROL | TSL2591_COMMAND_BIT);
+    control &= 0b11111000;
+    control |= integration_time;
+    watch_i2c_write8(TSL2591_ADDRESS, TSL2591_REGISTER_CONTROL | TSL2591_COMMAND_BIT, control);
+}
+
+uint16_t tsl2591_get_visible_light_reading() {
+    uint16_t full = make_le_16(watch_i2c_read16(TSL2591_ADDRESS, TSL2591_REGISTER_CHAN0_LOW | TSL2591_COMMAND_BIT));
+    uint16_t infrared = make_le_16(watch_i2c_read16(TSL2591_ADDRESS, TSL2591_REGISTER_CHAN1_LOW | TSL2591_COMMAND_BIT));
+    printf("Full Spectrum : %d\n", full);
+    printf("Infrared      : %d\n", infrared);
+    int32_t result = full - infrared;
+
+    return (result > 0) ? (uint16_t)result : 0;
+}
+\ No newline at end of file