diff --git a/Codec/Dragino-RS485-BL-PM.js b/Codec/Dragino-RS485-BL-PM.js
new file mode 100644
index 0000000..bc4b304
--- /dev/null
+++ b/Codec/Dragino-RS485-BL-PM.js
@@ -0,0 +1,46 @@
+// Decode uplink function.
+//
+// Input is an object with the following fields:
+// - bytes = Byte array containing the uplink payload, e.g. [255, 230, 255, 0]
+// - fPort = Uplink fPort.
+// - variables = Object containing the configured device variables.
+//
+// Output must be an object with the following fields:
+// - data = Object representing the decoded payload.
+// AT configuration for Dragino RS485-BL and RS485 PM 1.0/2.5/10 sensor
+// AT+5VT=3000
+// AT+MBFUN=1
+// AT+BAUDR=9600
+// AT+COMMAND1=01 03 00 00 00 03 ,1     AT+SEARCH1=0,0     AT+DATACUT1=0,0,0     AT+CMDDL1=2000
+function decodeUplink(input) {
+  var bytes = input.bytes;
+
+  // Only accept fPort=2. Ignore fPort=4
+  if(input.fPort != 2) {
+    return {"data": {}};
+  }
+  
+  var BatV = (bytes[0] << 8 | bytes[1]) / 1000 + 0.277;
+  var PayVER = bytes[2];
+  // If AT+DATAUP=1, PayloadCount=1 byte, payload#=1 byte
+  var PM2_5 = bytes[3] == 0xff && bytes[4] == 0xff? -1: bytes[3] << 8 | bytes[4];
+  var PM10  = bytes[5] == 0xff && bytes[6] == 0xff? -1: bytes[5] << 8 | bytes[6];
+  var PM1_0 = bytes[7] == 0xff && bytes[8] == 0xff? -1: bytes[7] << 8 | bytes[8];  
+    return {
+    data: {
+      "BatV": BatV, "PM2_5": PM2_5, "PM10": PM10, "PM1_0": PM1_0
+    }
+  };
+}
+
+// Encode downlink function.
+//
+// Input is an object with the following fields:
+// - data = Object representing the payload that must be encoded.
+// - variables = Object containing the configured device variables.
+//
+// Output must be an object with the following fields:
+// - bytes = Byte array containing the downlink payload.
+function encodeDownlink(input) {
+  return {bytes: []};
+}