# SPDX-FileCopyrightText: 2024 Ladyada for Adafruit Industries # SPDX-License-Identifier: MIT # Simple demo of sending and recieving data with the RFM9x or RFM69 radios. # Author: Jerry Needell import board import busio import digitalio # Define radio parameters. RADIO_FREQ_MHZ = 915.0 # Frequency of the radio in Mhz. Must match your # module! Can be a value like 915.0, 433.0, etc. # Define pins connected to the chip, use these if wiring up the breakout according to the guide: CS = digitalio.DigitalInOut(board.CE1) RESET = digitalio.DigitalInOut(board.D25) # Initialize SPI bus. spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO) # Initialze RFM radio # uncommnet the desired import and rfm initialization depending on the radio boards being used # Use rfm9x for two RFM9x radios using LoRa # from adafruit_rfm import rfm9x # rfm = rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ) # Use rfm9xfsk for two RFM9x radios or RFM9x to RFM69 using FSK from adafruit_rfm import rfm9xfsk rfm = rfm9xfsk.RFM9xFSK(spi, CS, RESET, RADIO_FREQ_MHZ) # Use rfm69 for two RFM69 radios using FSK # from adafruit_rfm import rfm69 # rfm = rfm69.RFM69(spi, CS, RESET, RADIO_FREQ_MHZ) # For RFM69 only: Optionally set an encryption key (16 byte AES key). MUST match both # on the transmitter and receiver (or be set to None to disable/the default). # rfm.encryption_key = None # rfm.encryption_key = ( # b"\x01\x02\x03\x04\x05\x06\x07\x08\x01\x02\x03\x04\x05\x06\x07\x08" # ) # for OOK on RFM69 or RFM9xFSK # rfm.modulation_type = 1 # Send a packet. Note you can only send a packet containing up to 60 bytes for an RFM69 # and 252 bytes forn an RFM9x. # This is a limitation of the radio packet size, so if you need to send larger # amounts of data you will need to break it into smaller send calls. Each send # call will wait for the previous one to finish before continuing. rfm.send(bytes("Hello world!\r\n", "utf-8")) print("Sent Hello World message!") # Wait to receive packets. print("Waiting for packets...") while True: packet = rfm.receive() # Optionally change the receive timeout from its default of 0.5 seconds: # packet = rfm9x.receive(timeout=5.0) # If no packet was received during the timeout then None is returned. if packet is None: # Packet has not been received print("Received nothing! Listening again...") else: # Received a packet! # Print out the raw bytes of the packet: print(f"Received (raw bytes): {packet}") # And decode to ASCII text and print it too. Note that you always # receive raw bytes and need to convert to a text format like ASCII # if you intend to do string processing on your data. Make sure the # sending side is sending ASCII data before you try to decode! try: packet_text = str(packet, "ascii") print(f"Received (ASCII): {packet_text}") except UnicodeError: print("Hex data: ", [hex(x) for x in packet]) # Also read the RSSI (signal strength) of the last received message and # print it. rssi = rfm.last_rssi print(f"Received signal strength: {rssi} dB")