diff --git a/Browan/TBDW100/decoder.js b/Browan/TBDW100/decoder.js
new file mode 100644
index 0000000..c02f69f
--- /dev/null
+++ b/Browan/TBDW100/decoder.js
@@ -0,0 +1,49 @@
+/* 
+* Payload decoder for the Browan TBDW100 Door and Window sensor.
+*/
+
+function Decoder(bytes, port) {
+
+    // Decoder output
+    var output = {};
+
+    // Door open/close status in various formats
+    statusValue = bytes[0] & 0x1;
+    // 1: open, 0: closed
+    statusReadble = "open";
+    statusBoolean = true;
+    if (statusValue == 0) {
+        statusReadble = "closed";
+        statusBoolean = false;
+    }
+
+    // Battery voltage
+    batteryVoltage = bytes[1] & 0x0f;
+
+    batteryVoltage = (25 + batteryVoltage) / 10;
+    batteryCapacity = (batteryCapacity / 15) * 100;
+
+    // PCB temperature measurement
+    temperature = bytes[2] & 0x7f;
+
+    // Temperature in °C = t - 32.
+    temperature = temperature - 32;
+
+    // Time elapsed since the last event-triggered
+    time = (bytes[4] << 8) | bytes[3];
+
+    // Total count of event-triggered (since boot)
+    count = ((bytes[7] << 16) | (bytes[6] << 8)) | bytes[5];
+
+    // Output construction
+    output.status_raw = statusValue;
+    output.status_readable = statusReadble;
+    output.status_open_boolean = statusBoolean;
+    output.battery_voltage = batteryVoltage;
+    output.temperature = temperature;
+    output.time = time;
+    output.count = count;
+    output.port = port;
+
+    return output;
+}