lightricity-decoder.js

function Decoder(request) {
	var payload = JSON.parse(request.body);
	var sensor_data;
	//refer page 3 for Lightricity data types and assigned numbers
	var Lightricity_data = [
		'Vendor ID', //0
		'Sensor ID',
		'Beacon Counter',
		'MAC Address',
		'TX Power',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'',
		'Temperature', //21 "Humidity", //22 "Pressure",
		'Lux',
		'Co2',
		'Acceleration',
		'Motion',
		'Button Event',
		'Battery Voltage',
	];

	var offset = 0;
	var valid_data_len, rawData_len, sensor_data, frame_type;

	for (var i = 0; i < payload.length; i++) {
		var deviceData = payload[i];
		if (deviceData.type === 'Gateway') continue;

		var rawData = deviceData.rawData;
		rawData_len = rawData.length;

		for (; offset < rawData_len; ) {
			valid_data_len = rawData.slice(offset, offset + 2);
			valid_data_len = parseInt(valid_data_len, 16);
			if (rawData.slice(offset + 2, offset + 8) == 'FF960A') {
				// Found Lightricity manufacturer specific data
				break;
			} else {
				//Discard non-Lightricity payloads offset += ((valid_data_len + 1) * 2);
			}
		}

		if (offset == rawData_len) {
			//No relevant data found
			return;
		}

		//Lightricity data found
		valid_data_len = rawData.slice(offset, offset + 2);
		valid_data_len = parseInt(valid_data_len, 16);
		offset = offset + 8;
		frame_type = rawData.slice(offset, offset + 2);
		if (frame_type == '01') {
			offset = offset + 2;
			//discard companyID, frame type, manufact flag valid_data_len = valid_data_len - 4;
			for (; valid_data_len > 0; ) {
				var dat_type = rawData.slice(offset, offset + 2);
				//extract data type from bit 0-5 dat_type = parseInt(dat_type, 16); dat_type = dat_type & 0x3F;
				if (dat_type == 21 || dat_type == 22) {
					dat_len = 2; //Temp and humidity always 2bytes
				} else if (dat_type == 26 || dat_type == 3) {
					dat_len = 6; //Acceleration/MAC always 6bytes
				} else {
					//extract data length from bit 6 & 7 dat_len = rawData.slice(offset,offset+1); dat_len = dat_len & 0xC;
					dat_len = (dat_len >> 2) + 1;
				}
				offset = offset + 2;
				sensor_data = rawData.slice(offset, offset + dat_len * 2);
				var sens_data_big_endi = '';
				var len = sensor_data.length - 2;
				for (; len >= 0; ) {
					//convert to big endian
					sens_data_big_endi += sensor_data.slice(len, len + 2);
					len = len - 2;
				}

				sensor_data = parseInt(sens_data_big_endi, 16);

				if (dat_type == 21 || dat_type == 22) {
					//refer page 3 for various data types and formats
					if (dat_type == 21) {
						//signed data
						if ((sensor_data & 0x8000) > 0) {
							sensor_data = sensor_data - 0x10000;
						}
					}
					sensor_data = sensor_data / 100;
				}
				offset = offset + dat_len * 2;
				valid_data_len = valid_data_len - dat_len - 1;

				//You have valid sensor data and data type in variables “sensor_data” and “Lightricity_data[dat_type]” respectively. Please use this as needed. “push_data_to_dashboard()” is an example API which pushes all sensor data and data type string to the dashboard. User can decide which data needs to be processed, and others can be discarded.

				push_data_to_dashboard(Lightricity_data[dat_type], sensor);
			}
		} else if (frame_type == '02') {
			/*
var vendor_ID = parseInt(rawData.slice(offset,offset+2),16); offset += 2;
//3 bytes sensor_ID
var sensor_ID = (rawData.slice(offset+4,offset+6)) + (rawData.slice(offset+2,offset+4)) + (rawData.slice(offset,offset+2)); sensor_ID = parseInt(sensor_ID, 16);
offset += 6;
var Beacon_Cnt = (rawData.slice(offset+2,offset+4)) + (rawData.slice(offset,offset+2)) Beacon_Cnt = parseInt(Beacon_Cnt, 16);
*/
		}
	}
}