1  # Example to receive addressed packed with ACK and send a response
 2  # Author: Jerry Needell
 3  #
 4  import time
 5  import board
 6  import busio
 7  import digitalio
 8  import adafruit_rfm69
 9  
10  # Define radio parameters.
11  RADIO_FREQ_MHZ = 915.0  # Frequency of the radio in Mhz. Must match your
12  # module! Can be a value like 915.0, 433.0, etc.
13  
14  # Define pins connected to the chip.
15  # set GPIO pins as necessary - this example is for Raspberry Pi
16  CS = digitalio.DigitalInOut(board.CE1)
17  RESET = digitalio.DigitalInOut(board.D25)
18  
19  # Initialize SPI bus.
20  spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
21  # Initialze RFM radio
22  rfm69 = adafruit_rfm69.RFM69(spi, CS, RESET, RADIO_FREQ_MHZ)
23  
24  # Optionally set an encryption key (16 byte AES key). MUST match both
25  # on the transmitter and receiver (or be set to None to disable/the default).
26  rfm69.encryption_key = (
27      b"\x01\x02\x03\x04\x05\x06\x07\x08\x01\x02\x03\x04\x05\x06\x07\x08"
28  )
29  
30  # set delay before transmitting ACK (seconds)
31  rfm69.ack_delay = 0.1
32  # set node addresses
33  rfm69.node = 2
34  rfm69.destination = 1
35  # initialize counter
36  counter = 0
37  ack_failed_counter = 0
38  
39  # Wait to receive packets.
40  print("Waiting for packets...")
41  while True:
42      # Look for a new packet: only accept if addresses to my_node
43      packet = rfm69.receive(with_ack=True, with_header=True)
44      # If no packet was received during the timeout then None is returned.
45      if packet is not None:
46          # Received a packet!
47          # Print out the raw bytes of the packet:
48          print("Received (raw header):", [hex(x) for x in packet[0:4]])
49          print("Received (raw payload): {0}".format(packet[4:]))
50          print("RSSI: {0}".format(rfm69.last_rssi))
51          # send response 2 sec after any packet received
52          time.sleep(2)
53          counter += 1
54          # send a  mesage to destination_node from my_node
55          if not rfm69.send_with_ack(
56              bytes("response from node {} {}".format(rfm69.node, counter), "UTF-8")
57          ):
58              ack_failed_counter += 1
59              print(" No Ack: ", counter, ack_failed_counter)