diff --git a/code/b-parasite/src/main.c b/code/b-parasite/src/main.c
index 4c49e45..5c8f055 100644
--- a/code/b-parasite/src/main.c
+++ b/code/b-parasite/src/main.c
@@ -26,7 +26,7 @@ static void log_init(void) {
 static void gpio_init(void) {
   nrf_gpio_cfg_output(PRST_LED_PIN);
   nrf_gpio_cfg_output(PRST_FAST_DISCH_PIN);
-#ifdef PRST_HAS_LDR
+#if PRST_HAS_LDR
   nrf_gpio_cfg_output(PRST_PHOTO_V_PIN);
 #endif
   NRF_LOG_INFO("GPIO pins inited.");
@@ -67,7 +67,7 @@ static void rtc_callback() {
   nrf_gpio_pin_clear(PRST_FAST_DISCH_PIN);
 
   uint16_t lux = 0;
-#ifdef PRST_HAS_LDR
+#if PRST_HAS_LDR
   nrf_gpio_pin_set(PRST_PHOTO_V_PIN);
   prst_adc_photo_sensor_t photo_read = prst_adc_photo_read(batt_read.voltage);
   nrf_gpio_pin_clear(PRST_PHOTO_V_PIN);
diff --git a/code/b-parasite/src/prst/adc.h b/code/b-parasite/src/prst/adc.h
index 2a733db..3b568b8 100644
--- a/code/b-parasite/src/prst/adc.h
+++ b/code/b-parasite/src/prst/adc.h
@@ -18,9 +18,8 @@ typedef struct prst_adc_soil_moisture {
 
 typedef struct prst_adc_photo_sensor {
   int16_t raw;
-  // A value from 0x0000 (no light) 0xffff (direct sun).
-  // Might need calibration.
   double voltage;
+  // Value in lux.
   uint16_t brightness;
 } prst_adc_photo_sensor_t;