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receiving small up to 252 byte control messages and not large or high bandwidth amounts of data.

Here's a complete example of sending a message and waiting to receive and print any received messages. Save this

as main.py on your board and open the serial REPL to see it print data and any received messages. If you have two

boards and radios setup to run this code at the same time they'll send each other a message on start up!

# Simple demo of sending and recieving data with the RFM95 LoRa radio.

# Author: Tony DiCola

import board

import busio

import digitalio

import adafruit_rfm9x

# 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.D5)

RESET = digitalio.DigitalInOut(board.D6)

# Or uncomment and instead use these if using a Feather M0 RFM9x board and the appropriate

# CircuitPython build:

#CS = digitalio.DigitalInOut(board.RFM9X_CS)

#RESET = digitalio.DigitalInOut(board.RFM9X_RST)

# Initialize SPI bus.

spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)

# Initialze RFM radio

rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ)

# Note that the radio is configured in LoRa mode so you can't control sync

# word, encryption, frequency deviation, or other settings!

# You can however adjust the transmit power (in dB). The default is 13 dB but

# high power radios like the RFM95 can go up to 23 dB:

rfm9x.tx_power = 23

# Send a packet. Note you can only send a packet up to 252 bytes in length.

# 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.

rfm9x.send('Hello world!\r\n')

print('Sent hello world message!')

# Wait to receive packets. Note that this library can't receive data at a fast

# rate, in fact it can only receive and process one 252 byte packet at a time.

# This means you should only use this for low bandwidth scenarios, like sending

# and receiving a single message at a time.

print('Waiting for packets...')

while True:

packet = rfm9x.receive()

# Optionally change the receive timeout from its default of 0.5 seconds:

#packet = rfm9x.receive(timeout_s=5.0)

# If no packet was received during the timeout then None is returned.

if packet is None:

print('Received nothing! Listening again...')

https://learn.adafruit.com/adafruit-rfm69hcw-and-rfm96-rfm95-rfm98-lora-packet-padio-

breakouts

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