diff --git a/.gitignore b/.gitignore
index 03f4a3c..e0db434 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
+.env
 .pio
diff --git a/platformio.ini b/platformio.ini
index 1d3415e..38b4de1 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -13,6 +13,11 @@ platform = espressif32
 board = heltec_wifi_lora_32_V2
 framework = arduino
 
+build_flags =
+  -D DEVEUI=\"${sysenv.DEVEUI}\"
+  -D APPEUI=\"${sysenv.APPEUI}\"
+  -D APPKEY=\"${sysenv.APPKEY}\"
+
 lib_deps =
   Heltec ESP32 Dev-Boards@1.0.9
   TTN_esp32@0.1.0
diff --git a/src/config.hh b/src/config.hh
new file mode 100644
index 0000000..dc8fef6
--- /dev/null
+++ b/src/config.hh
@@ -0,0 +1,24 @@
+// Logic: Below charging voltage deep-sleep is used, above delay as
+// battery is provided power
+#define BATTERY_LOAD_VOLTAGE  13.5          // 14V SHOULD be supplied during charge
+#define BATTERY_SLEEP_US      240 * 1000000 // 240s of deep sleep = 360 wake-ups / day
+#define CHARGE_SLEEP_MS       30 * 1000     // 30s delay between measurements during charging
+
+// Debug: Allow to enable / disable LoRa sending / deep sleep
+#define DISABLE_SLEEP         false
+#define ENABLE_SEND           true
+
+// PIN to which the voltage sensor is connected
+#define PIN_VOLTAGE_READ      32
+
+// Adjustments for the measurement to work around unstable measurements
+#define CORRECT_DIFF          0.90  // Measurement isn't fully accurate, lets adjust
+#define MEAS_COUNT            16    // How many readings to make for each measurement
+
+// LoRaWAN configuration
+#define BAND  868E6 // 868MHz = Europe transfer channel
+
+// Defined through environment variable during build, see platformio.ini
+const char* devEui = DEVEUI; // TTN Device EUI
+const char* appEui = APPEUI; // TTN Application EUI
+const char* appKey = APPKEY; // TTN Application Key
diff --git a/src/main.cpp b/src/main.cpp
index 86da80a..c526ab9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3,7 +3,7 @@
 #include <TTN_esp32.h>
 #include "heltec.h"
 
-#include "config.h"
+#include "config.hh"
 #include "main.hh"
 #include "math.hh"