Adds decoder class for LSN50v2 (d20/22/23) devices

LSN50v2-D20-D22-D23/LSN50v2-D20.js

@@ -0,0 +1,100 @@
+// https://github.com/dragino/dragino-end-node-decoder/blob/main/LSN50v2-D20-D22-D23/LSN50v2-D20-Decoder.txt
+
+class LSN50v2 {
+
+    // Takes base64 encoded payload string
+    static decode(payload) {
+        let bytes = Uint8Array.from(Buffer.from(payload, 'base64'));
+
+        let mode = (bytes[6] & 0x7C)>>2;
+        let decode = {};
+
+        if ((mode != 2) && (mode != 31)) {
+            decode.BatV = (bytes[0]<<8 | bytes[1])/1000;
+            decode.TempC1 = parseFloat(((bytes[2]<<24>>16 | bytes[3])/10).toFixed(2));
+            decode.ADC_CH0V = (bytes[4]<<8 | bytes[5])/1000;
+            decode.Digital_IStatus = (bytes[6] & 0x02) ? "H":"L";
+
+            if (mode != 6) {
+                decode.EXTI_Trigger = (bytes[6] & 0x01) ? "TRUE":"FALSE";
+                decode.Door_status = (bytes[6] & 0x80) ? "CLOSE":"OPEN";
+            }
+        }
+
+        if (mode == '0') {
+            decode.Work_mode = "IIC";
+
+            if ((bytes[9]<<8 | bytes[10])===0) {
+                decode.Illum = (bytes[7]<<24>>16 | bytes[8]);
+            }
+
+            else {
+              decode.TempC_SHT = parseFloat(((bytes[7]<<24>>16 | bytes[8])/10).toFixed(2));
+              decode.Hum_SHT = parseFloat(((bytes[9]<<8 | bytes[10])/10).toFixed(1));
+            }
+        }
+
+        else if (mode == '1') {
+            decode.Work_mode ="Distance";
+            decode.Distance_cm = parseFloat(((bytes[7]<<8 | bytes[8])/10).toFixed(1));
+
+            if ((bytes[9]<<8 | bytes[10]) != 65535) {
+                decode.Distance_signal_strength = parseFloat((bytes[9]<<8 | bytes[10]).toFixed(0));
+            }
+        }
+
+        else if (mode == '2') {
+            decode.Work_mode = "3ADC";
+            decode.BatV = bytes[11]/10;
+            decode.ADC_CH0V = (bytes[0]<<8 | bytes[1])/1000;
+            decode.ADC_CH1V = (bytes[2]<<8 | bytes[3])/1000;
+            decode.ADC_CH4V = (bytes[4]<<8 | bytes[5])/1000;
+            decode.Digital_IStatus = (bytes[6] & 0x02) ? "H":"L";
+            decode.EXTI_Trigger = (bytes[6] & 0x01) ? "TRUE":"FALSE";
+            decode.Door_status = (bytes[6] & 0x80) ? "CLOSE":"OPEN";
+
+            if ((bytes[9]<<8 | bytes[10]) === 0) {
+                decode.Illum = (bytes[7]<<24>>16 | bytes[8]);
+            }
+
+            else {
+                decode.TempC_SHT = parseFloat(((bytes[7]<<24>>16 | bytes[8])/10).toFixed(2));
+                decode.Hum_SHT = parseFloat(((bytes[9]<<8 | bytes[10])/10).toFixed(1));
+            }
+        }
+
+        else if (mode == '3') {
+            decode.Work_mode="3DS18B20";
+            decode.TempC2 = parseFloat(((bytes[7]<<24>>16 | bytes[8])/10).toFixed(2));
+            decode.TempC3 = parseFloat(((bytes[9]<<24>>16 | bytes[10])/10) .toFixed(1));
+        }
+
+        else if (mode == '4') {
+            decode.Work_mode = "Weight";
+            decode.Weight = (bytes[7]<<24>>16 | bytes[8]);
+        }
+
+        else if (mode == '5') {
+            decode.Work_mode = "Count";
+            decode.Count = (bytes[7]<<24 | bytes[8]<<16 | bytes[9]<<8 | bytes[10]);
+        }
+
+        else if (mode == '31') {
+            decode.Work_mode = "ALARM";
+            decode.BatV = (bytes[0]<<8 | bytes[1])/1000;
+            decode.TempC1 = parseFloat(((bytes[2]<<24>>16 | bytes[3])/10).toFixed(2));
+            decode.TempC1MIN = bytes[4]<<24>>24;
+            decode.TempC1MAX = bytes[5]<<24>>24; 
+            decode.SHTEMPMIN = bytes[7]<<24>>24;
+            decode.SHTEMPMAX = bytes[8]<<24>>24;   
+            decode.SHTHUMMIN = bytes[9];
+            decode.SHTHUMMAX = bytes[10];    
+        }
+
+        if ((bytes.length == 11) || (bytes.length == 12)) {
+            return decode;
+        }
+    }
+}
+
+export default LSN50v2;