LoRaWAN Capacitive Soil Moisture/Water content, Temperature and EC sensor

The PM-WCS-3 family sensors is low-cost, accurate soil moisture sensor for monitoring water content, electrical conductivity and temperature of soil.

Features:

• Dust and water proof IP67.

• LoRaWAN class A device, may be activated with OTAA or ABP for any LoRaWAN network.

• Setup via USB CDC-ACM virtual COM port.

• Android application for USB setup.

Power Consumption

Sensor sleep mode consumes 0.15 mA. Active mode consumption 12-24 mA depending on sensor configuration and 150 mA in transmitting mode. Required battery is 3.7v 18650. Device may be powered from any 5v Micro-USB power source. After power up sensors wait 10 seconds for USB configuration session connection from android application or USB CDC terminal, if none is connected sensors turns off USB hardware and starts normal operation. Device should be restarted, before attaching to USB for configuration, it means battery should be removed

Sensor calibration via Android application

Get it on Google Play

1. remove battery, attach to phone
2. open application & wait for  USB connected status or connect
3. go to SETTINGS tab, 
4. hold sensor in the air - click button AIR
5. submerge sensor in the water or soil with water, click button WATER
6. go to MAIN tab, click "read" button to check calibrated values
7. To connect to LoRaWAN, disconnect from phone and connect to battery or any (other then android phone) Micro-USB power source.

TTN application payload format:

``` var bytesToInt = function(/byte[]/byteArray, dev) { var value = 0; for ( var i = 0; i < byteArray.length; i++) { value = (value * 256) + byteArray[i]; } return value/dev; }; var bytesToSignedInt = function(bytes, dev) { var sign = bytes[0] & (1 << 7); var x = ((bytes[0] & 0xFF) << 8) | (bytes[1] & 0xFF); if (sign) { x = 0xFFFF0000 | x; } return x/dev; };

function Decoder(bytes, port) { var decoded = {}; var pos = 1; decoded.valve=((bytes[0] >> 7) & 1); decoded.leak=((bytes[0] >> 6) & 1); decoded.bat = bytes[pos++]; if(((bytes[0] >> 0) & 1)===1){ //SOIL decoded.e25=bytesToInt(bytes.slice(pos,pos+2),100); pos = pos+2; decoded.ec=bytesToInt(bytes.slice(pos,pos+2),10); pos = pos+2; decoded.temp=bytesToSignedInt(bytes.slice(pos,pos+2),100); pos = pos+2; decoded.vwc=bytesToInt(bytes.slice(pos,pos+2),1); pos = pos+2; } if(((bytes[0] >> 1) & 1)===1){ //BME decoded.airTemp=bytesToSignedInt(bytes.slice(pos,pos+2),100); pos = pos+2; decoded.airHum=bytesToInt(bytes.slice(pos,pos+2),100); pos = pos+2; decoded.airPres=bytesToInt(bytes.slice(pos,pos+2),1)+50000; pos = pos+2; } if(((bytes[0] >> 2) & 1)===1){ //OPT decoded.lux=bytesToInt(bytes.slice(pos,pos+4),100); pos = pos+4; } if(((bytes[0] >> 4) & 1)===1){ //PULSE decoded.pulse=bytesToInt(bytes.slice(pos,pos+4),1); pos = pos+4; } return decoded; }

```