function_node

// Function node to parse VE.Direct data received from Node-RED serial node 

// Input: msg.payload contains the array of bytes
let data = msg.payload;

function parseVEData(data) {
    let parsed = {};
    let dataStr = '';

    // Convert byte array to string for easier processing
    for (let i = 0; i < data.length; i++) {
        dataStr += String.fromCharCode(data[i]);
    }

    // Split the raw data string into lines
    let lines = dataStr.split('\r\n');

    // Variables to hold intermediate values
    let panelVoltage = 0;
    let panelPower = 0;

    // Iterate through each line and extract key-value pairs
    lines.forEach(line => {
        let [key, value] = line.split('\t');
        if (key && value) {
            key = key.trim();
            value = value.trim();

            // Parse specific fields based on VE.Direct protocol
            switch (key) {
                case 'PID':
                    parsed.VictronProductId = value;
                    break;
                case 'FWE':
                    parsed.VictronFirmwareVersion = value;
                    break;
                case 'SER#':
                    parsed.VictronSerialNumber = value;
                    break;
                case 'V':
                    parsed.VictronBatteryVoltage = parseInt(value) / 1000.0;
                    break;
                case 'I':
                    parsed.VictronBatteryCurrent = parseInt(value) / 1000.0;
                    break;
                case 'VPV':
                    panelVoltage = parseInt(value) / 1000.0;
                    parsed.VictronSolarVoltage = panelVoltage;
                    break;
                case 'PPV':
                    panelPower = parseInt(value);
                    parsed.VictronSolarPower = panelPower;
                    break;
                case 'MPPT':
                    parsed.VictronTrackingMode = parseInt(value);
                    break;
                case 'CS':
                    parsed.VictronChargingMode = parseInt(value);
                    break;
                case 'ERR':
                    parsed.VictronError = parseInt(value);
                    break;
                case 'H19':
                    parsed.VictronYieldTotal = parseInt(value) * 10; // Adjust based on actual units
                    break;
                case 'H20':
                    parsed.VictronYieldToday = parseInt(value) * 10; // Adjust based on actual units
                    break;
                case 'H21':
                    parsed.VictronMaxPowerToday = parseInt(value);
                    break;
                case 'H22':
                    parsed.VictronYieldYesterday = parseInt(value) * 10; // Adjust based on actual units
                    break;
                case 'H23':
                    parsed.VictronMaxPowerYesterday = parseInt(value);
                    break;
                case 'HSDS':
                    parsed.VictronDayNumber = parseInt(value);
                    // Calculate solar current
                    parsed.VictronSolarCurrent = (panelVoltage > 0 && panelPower > 0) ? panelPower / panelVoltage : 0;
                    break;
                // Add more cases as needed
            }
        }
    });

    // Generate separate messages for each key-value pair
    let messages = [];
    for (let key in parsed) {
        if (parsed.hasOwnProperty(key)) {
            let message = { topic: key, payload: parsed[key] };
            node.send(message);  // Send each message separately
        }
    }

    return null; // No need to return a single object
}

// Parse the data
parseVEData(data);