function decodeUplink(input) {
    const b = input.bytes;
    const pulses = (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3];
    return {
        data: {
            pulse_count: pulses,
            index_m3:    (pulses * 0.010).toFixed(3)
        }
    };
}