BROWAN - Industrial Tracker

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/* eslint-disable no-bitwise */ function signed_convert(val, bitwidth) { const isnegative = val & (1 << (bitwidth - 1)); const boundary = 1 << bitwidth; const minval = -boundary; const mask = boundary - 1; return isnegative ? minval + (val & mask) : val; } function Decoder(bytes, port) { const decoded = []; if (port === 136) { decoded.push({ variable: "moving_mode", value: bytes[0] & 1 }); decoded.push({ variable: "no_gnss_fix", value: !!((bytes[0] & 0x8) >> 3) }); decoded.push({ variable: "temperature", value: (bytes.readUInt8(2) & 0x7f) - 32, unit: "°C", }); const battery = bytes[1]; // const capacity = battery >> 4; const voltage = battery & 0x0f; decoded.push({ variable: "battery", value: (25 + voltage) / 10, unit: "V", }); let accuracy = bytes[10] >> 5; accuracy = Math.pow(2, parseInt(accuracy) + 2); decoded.push({ variable: "accuracy", value: accuracy, unit: "m" }); // Mask off end of accuracy byte, so lon doesn't get affected bytes[10] &= 0x1f; if ((bytes[10] & (1 << 4)) !== 0) { bytes[10] |= 0xe0; } // Mask off end of lat byte, RFU //bytes[6] &= 0x0f; let lat = (bytes[6] << 24) | (bytes[5] << 16) | (bytes[4] << 8) | bytes[3]; let lon = (bytes[10] << 24) | (bytes[9] << 16) | (bytes[8] << 8) | bytes[7]; if (lat > 134217727) { lat = lat - 268435456; } lat /= 1000000; lon /= 1000000; decoded.push({ variable: "location", value: `${lat},${lon}`, location: { lat, lng: lon }, }); return decoded; } } const data = payload.find( (x) => x.variable === "payload" || x.variable === "payload_raw" || x.variable === "data" ); const port = payload.find( (x) => x.variable === "port" || x.variable === "fport" ); if (data && port) { const serie = data.serie || new Date().getTime(); const bytes = Buffer.from(data.value, "hex"); payload = payload .concat(Decoder(bytes, Number(port.value))) .map((x) => ({ ...x, serie })); }