@lora-contrib/node-red-contrib-payload-parser/nodes/node-red-contrib-payload-parser/helper/conversion.js

Parse Lora payload

function converter(buffer, type){
    var bufferValue = null;
    switch (type) {
        case 'int':
            if (buffer.length == 1){
                bufferValue = buffer.readUInt8(0);
            }else if (buffer.length == 2){
                bufferValue = buffer.readUInt16BE(0);
            }else if (buffer.length == 3){
                buffer = Buffer.concat([new Buffer([0x00]), buffer], 4);
                bufferValue = buffer.readUInt32BE(0);
            }else if (buffer.length == 4){
                bufferValue = buffer.readUInt32BE(0);
            }else{
                bufferValue = buffer.readUIntBE(0, buffer.length);
            }
            break;
        case 'sint':
            if (buffer.length == 1){
                bufferValue = buffer.readInt8(0);
            }else if (buffer.length == 2){
                bufferValue = buffer.readInt16BE(0);
            }else if (buffer.length == 3){
                buffer = Buffer.concat([new Buffer([0x00]), buffer], 4);
                bufferValue = buffer.readInt32BE(0);
            }else if (buffer.length == 4){
                bufferValue = buffer.readInt32BE(0);
            }else{
                bufferValue = buffer.readIntBE(0, message.length);
            }
            break;
        case 'float32':
        case 'float':
            bufferValue = Math.round(buffer.readFloatBE(0) * 100) / 100 ;
            break;
        case 'float64':
        case 'double':
            bufferValue = Math.round(buffer.readDoubleBE(0) * 100) / 100 ;
            break;
        case 'bin':
            bufferValue = hex2Bin(buffer.toString('hex'));
            break;
        case 'boolean':
            bufferValue = hexToBool(buffer.toString('hex'), 0);
            break;
        case 'hex':
            bufferValue = buffer.toString('hex');
            break;
        default: /* 'txt' */
            bufferValue = buffer.toString();
            break;
    }

    return bufferValue;
}

function hexToBool(hex, index){
	if (index >= hex.length*4) return null;
	return Boolean(parseInt(hex2Bin(hex).charAt(index)));
}

function hex2Bin(n){
	if(!checkHex(n))return null;
	return parseInt(n,16).toString(2);
}

function checkHex(n){return/^[0-9A-Fa-f]{1,64}$/.test(n)}

exports.converter = converter;