pyrou/node-teleinfo-server

/**
 * Return the checksum of a value and label
 */
var checksum = function (label, value) {
    var data = ('' + label + value);
    var sum = 32;
    for (var i=0,l=data.length; i<l; i++) {
        sum += data.charCodeAt(i);
    }
    return String.fromCharCode((sum & 63) + 32);
}

var integerKeys = [
    'ISOUSC', 'BASE', 'HCHC', 'HCHP', 'EJPHN', 'EJPHPM',
    'BBRHCJB', 'BBRHPJB', 'BBRHCJW', 'BBRHPJW', 'BBRHCJR', 'BBRHPJR',
    'PEJP', 'IINST', 'IINST1', 'IINST2', 'IINST3', 'ADPS', 'IMAX',
    'IMAX1', 'IMAX2', 'IMAX3', 'PAPP', 'ADIR1', 'ADIR2', 'ADIR3' ];

/**
 * Read and verify Teleinfo datagram and return it as an object
 */
var parse = function (message) {
    var line;
    var data = {};
    var lines = message.toString().replace(/^[\r\n\x03\x02]+|[\r\n\x03\x02]+$/g, '').split("\r\n");

    for(var i=0,l=lines.length; i<l; i++) {
        line = lines[i].split(' ', 3);
        if(line.length !== 3) continue;

        if(checksum(line[0], line[1]) == (line[2]||' ')) {
            data[line[0]] = integerKeys.indexOf(line[0]) >= 0 ? parseInt(line[1]) : line[1];
        }
    }
    return data;
}

module.exports.parse = parse;