def burst_write(addr, data):
    """Write multiple bytes to FIFO or registers"""
    BURST = 0x40
    spi.xfer2([addr | BURST] + data)


def send_packet(data):
    # Flush TX FIFO
    strobe(0x3B)  # SFTX

    # Load data to TX FIFO (fixed length)
    burst_write(0x3F, data)  # 0x3F = TX FIFO

    # Strobe STX to transmit
    strobe(0x35)  # STX

    print(f"Sent: {data}")