1  # Example to send a packet periodically between addressed nodes with ACK
 2  # Author: Jerry Needell
 3  #
 4  import time
 5  import board
 6  import busio
 7  import digitalio
 8  import adafruit_rfm9x
 9  
10  # set the time interval (seconds) for sending packets
11  transmit_interval = 10
12  
13  # Define radio parameters.
14  RADIO_FREQ_MHZ = 915.0  # Frequency of the radio in Mhz. Must match your
15  # module! Can be a value like 915.0, 433.0, etc.
16  
17  # Define pins connected to the chip.
18  # set GPIO pins as necessary -- this example is for Raspberry Pi
19  CS = digitalio.DigitalInOut(board.CE1)
20  RESET = digitalio.DigitalInOut(board.D25)
21  
22  # Initialize SPI bus.
23  spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
24  # Initialze RFM radio
25  rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ)
26  
27  # enable CRC checking
28  rfm9x.enable_crc = True
29  # set delay before sending ACK
30  rfm9x.ack_delay = 0.1
31  # set node addresses
32  rfm9x.node = 1
33  rfm9x.destination = 2
34  # initialize counter
35  counter = 0
36  ack_failed_counter = 0
37  # send startup message from my_node
38  rfm9x.send_with_ack(bytes("startup message from node {}".format(rfm9x.node), "UTF-8"))
39  
40  # Wait to receive packets.
41  print("Waiting for packets...")
42  # initialize flag and timer
43  time_now = time.monotonic()
44  while True:
45      # Look for a new packet: only accept if addresses to my_node
46      packet = rfm9x.receive(with_ack=True, with_header=True)
47      # If no packet was received during the timeout then None is returned.
48      if packet is not None:
49          # Received a packet!
50          # Print out the raw bytes of the packet:
51          print("Received (raw header):", [hex(x) for x in packet[0:4]])
52          print("Received (raw payload): {0}".format(packet[4:]))
53          print("RSSI: {0}".format(rfm9x.last_rssi))
54          # send reading after any packet received
55      if time.monotonic() - time_now > transmit_interval:
56          # reset timeer
57          time_now = time.monotonic()
58          counter += 1
59          # send a  mesage to destination_node from my_node
60          if not rfm9x.send_with_ack(
61              bytes("message from node node {} {}".format(rfm9x.node, counter), "UTF-8")
62          ):
63              ack_failed_counter += 1
64              print(" No Ack: ", counter, ack_failed_counter)