TTN Smart Sensor (Elvaco)

Codec Preview

const difVifMapping = { '00': { '2f': { measure: '', unit: '', decimal: 0 }, }, '01': { fd17: { measure: 'error_flag', unit: '', decimal: 0 }, }, '04': { '00': { measure: 'energy', unit: 'kWh', decimal: 6 }, '01': { measure: 'energy', unit: 'kWh', decimal: 5 }, '02': { measure: 'energy', unit: 'kWh', decimal: 4 }, '03': { measure: 'energy', unit: 'kWh', decimal: 3 }, '04': { measure: 'energy', unit: 'kWh', decimal: 2 }, '05': { measure: 'energy', unit: 'kWh', decimal: 1 }, '06': { measure: 'energy', unit: 'kWh', decimal: 0 }, '07': { measure: 'energy', unit: 'kWh', decimal: -1 }, 11: { measure: 'volume', unit: 'm3', decimal: 5 }, 12: { measure: 'volume', unit: 'm3', decimal: 4 }, 13: { measure: 'volume', unit: 'm3', decimal: 3 }, 14: { measure: 'volume', unit: 'm3', decimal: 2 }, 15: { measure: 'volume', unit: 'm3', decimal: 1 }, 16: { measure: 'volume', unit: 'm3', decimal: 0 }, 17: { measure: 'volume', unit: 'm3', decimal: -1 }, '6d': { measure: 'datetime_heat_meter', unit: '', decimal: 0 }, }, '02': { '2a': { measure: 'power', unit: 'kW', decimal: 4 }, '2b': { measure: 'power', unit: 'kW', decimal: 3 }, '2c': { measure: 'power', unit: 'kW', decimal: 2 }, '2d': { measure: 'power', unit: 'kW', decimal: 1 }, '2e': { measure: 'power', unit: 'kW', decimal: 0 }, '2f': { measure: 'power', unit: 'kW', decimal: -1 }, '3b': { measure: 'flow', unit: 'm3/h', decimal: 3 }, '3c': { measure: 'flow', unit: 'm3/h', decimal: 2 }, '3d': { measure: 'flow', unit: 'm3/h', decimal: 1 }, '3e': { measure: 'flow', unit: 'm3/h', decimal: 0 }, '3f': { measure: 'flow', unit: 'm3/h', decimal: -1 }, 58: { measure: 'flow_temperature', unit: '°C', decimal: 3 }, 59: { measure: 'flow_temperature', unit: '°C', decimal: 2 }, '5a': { measure: 'flow_temperature', unit: '°C', decimal: 1 }, '5b': { measure: 'flow_temperature', unit: '°C', decimal: 0 }, '5c': { measure: 'return_temperature', unit: '°C', decimal: 3 }, '5d': { measure: 'return_temperature', unit: '°C', decimal: 2 }, '5e': { measure: 'return_temperature', unit: '°C', decimal: 1 }, '5f': { measure: 'return_temperature', unit: '°C', decimal: 0 }, fd17: { measure: 'error_flag', unit: '', decimal: 0 }, }, '07': { 79: { measure: 'serial', unit: '', decimal: 0 } }, }; function decode_cmi4160_standard(payloadArr) { const decoded_dictionary = {}; let error_state = false; let i = 1; while (i < payloadArr.length) { const dif = payloadArr[i].toLowerCase(); const dif_int = parseInt(dif, 16); let vif = payloadArr[i + 1].toLowerCase(); i += 2; if (payloadArr.length - i <= 3 && vif == 'fd') { // end of payload: error flag vif += payloadArr[i]; i += 1; } let bcd_len = 4; if ((dif_int >= 2 && dif_int <= 4) || dif_int == 7) { bcd_len = dif_int; } if (!(dif in difVifMapping && vif in difVifMapping[dif])) { throw 'Unknown dif ' + dif + ' and vif dif in difVifMapping' + vif; } const reversed_values = payloadArr .slice(i, i + bcd_len) .reverse() .join(''); //Little-endian (LSB) i += bcd_len; unit_info = difVifMapping[dif][vif]; if (unit_info['unit']) { value = parseInt(reversed_values, 16) / Math.pow(10, unit_info['decimal']); } else if (unit_info['measure'] == 'serial') { value = parseInt(reversed_values.slice(-8)); // byte 2-5 is serial number i += 1; } else { value = parseInt(reversed_values, 16); } if (dif == '32') { decoded_dictionary[unit_info['measure']] = 0; error_state = true; } else { decoded_dictionary[unit_info['measure']] = value; } } if (error_state) { decoded_dictionary['error_flag'] = 32; } return decoded_dictionary; } function bytesToHexArray(bytes) { return bytes.map(function (byte) { return ('0' + (byte & 0xff).toString(16)).slice(-2); }); } function hexToBytes(hex) { const hexArray = hex.match(/.{1,2}/g); return hexArray.map(function (byte) { return parseInt(byte, 16); }); } function decodeUplink(input) { switch (input.fPort) { case 2: const hex_array = bytesToHexArray(input.bytes); if (hex_array.length < 40) { return { data: {}, errors: ['payload length < 40 '], }; } if (hex_array[0] != '1e') { return { data: {}, errors: ['Payload type unknown, currently standard format supported'], }; } return { data: decode_cmi4160_standard(hex_array), }; default: return { data: {}, errors: ['unknown FPort'], }; } } // bytes = [30, 4, 7, 233, 28, 5, 0, 4, 21, 141, 103, 15, 0, 50, 47, 75, 51, 50, 61, 55, 51, 50, 90, 89, 4, 50, 94, 89, 4, 7, 121, 34, 152, 132, 97, 165, 17, 64, 4, 1, 253, 23, 4]; // bytes = [30, 4, 6, 143, 161, 1, 0, 4, 19, 132, 183, 30, 0, 2, 43, 207, 15, 2, 59, 93, 0, 2, 90, 16, 3, 2, 94, 152, 1, 7, 121, 130, 37, 50, 105, 165, 17, 64, 4, 1, 253, 23, 0]; // input = { fPort: 2, bytes: bytes }; // console.log(decodeUplink(input));