To use with CircuitPython, you need to first install a few libraries into the lib folder on the CIRCUITPY drive which appears on your computer when the Feather board is plugged in via USB. Then you need to update code.py with the example script.
Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory RP2040_Radio_Messenger/ and then click on the directory that matches the version of CircuitPython you're using.
Connect your RP2040 board to your computer via a known good USB data+power cable. The board should show up as a thumb drive named CIRCUITPY in Explorer or Finder (depending on your operating system). Copy code.py and the lib/ directory to your CIRCUITPY drive.
Your CIRCUITPY drive should now look similar to the following image:
# SPDX-FileCopyrightText: 2023 Eva Herrada for Adafruit Industries
# SPDX-License-Identifier: MIT
import time
import random
import board
import usb_cdc
import digitalio
import adafruit_rfm9x
spi = board.SPI()
# radio setup
RADIO_FREQ_MHZ = 915.0
LED = digitalio.DigitalInOut(board.LED)
LED.direction = digitalio.Direction.OUTPUT
CS = digitalio.DigitalInOut(board.RFM_CS)
RESET = digitalio.DigitalInOut(board.RFM_RST)
rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ)
rfm9x.tx_power = 23
# 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...")
MESSAGE = b""
ID = None
while True:
char = usb_cdc.console.read(usb_cdc.console.in_waiting)
if char:
MESSAGE += char
# print(char.decode('utf-8'), end="")
if char[-1:] == b"\r":
MESSAGE = MESSAGE[:-1]
ID = random.randint(0, 1000)
rfm9x.send(bytes(f"{ID}|", "utf-8") + MESSAGE)
print(f"{ID}|{MESSAGE.decode()}")
timestamp = time.monotonic()
sent = MESSAGE
MESSAGE = b""
continue
packet = rfm9x.receive()
if packet is None:
# Packet has not been received
LED.value = False
else:
# Received a packet!
LED.value = True
try:
PACKET_TEXT = str(packet, "ascii")
except UnicodeError:
print("error")
continue
print(PACKET_TEXT)
mess_id, text = PACKET_TEXT.split("|")
if mess_id != "-1":
rfm9x.send(bytes(f"-1|{mess_id}", "utf-8"))
print(f"Received: {PACKET_TEXT}")
else:
print(f"Delivered: {text}")
ID = None
rssi = rfm9x.last_rssi
print(f"RSSI: {rssi} dB")
Now, go into client.py and edit the NUMBER variable to the phone number associated with your Signal account connected to a GUI.
Page last edited January 22, 2025
Text editor powered by tinymce.
