This guide assumes that you've gotten your Raspberry Pi up and running, and have CircuitPython installed.
Installing CircuitPython Libraries
We're running CircuitPython on the Raspberry Pi, installing the libraries for radio communication is simple.
To install the library for the display, enter the following into the terminal:
sudo pip3 install adafruit-circuitpython-ssd1306
You'll also need to install the framebuf module in order to write to the display.
sudo pip3 install adafruit-circuitpython-framebuf
To install the library for the RFM9x Module, enter the following into the terminal:
sudo pip3 install adafruit-circuitpython-rfm9x
You'll also want to download the font file, font5x8.bin, and copy it into the same directory as the script
wget https://github.com/adafruit/Adafruit_CircuitPython_framebuf/raw/main/examples/font5x8.bin
Make sure the font file is 1282 bytes long, if not something went wrong with the download
The following code is for checking if the RFM9x radio is set up for transmitting and receiving. Save the code on your Pi (save this to a location you can remember, like your Desktop or Downloads folder) as rfm9x_check.py.
# SPDX-FileCopyrightText: 2018 Brent Rubell for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
Wiring Check, Pi Radio w/RFM9x
Learn Guide: https://learn.adafruit.com/lora-and-lorawan-for-raspberry-pi
Author: Brent Rubell for Adafruit Industries
"""
import time
import busio
from digitalio import DigitalInOut, Direction, Pull
import board
# Import the SSD1306 module.
import adafruit_ssd1306
# Import the RFM9x radio module.
import adafruit_rfm9x
# Button A
btnA = DigitalInOut(board.D5)
btnA.direction = Direction.INPUT
btnA.pull = Pull.UP
# Button B
btnB = DigitalInOut(board.D6)
btnB.direction = Direction.INPUT
btnB.pull = Pull.UP
# Button C
btnC = DigitalInOut(board.D12)
btnC.direction = Direction.INPUT
btnC.pull = Pull.UP
# Create the I2C interface.
i2c = busio.I2C(board.SCL, board.SDA)
# 128x32 OLED Display
reset_pin = DigitalInOut(board.D4)
display = adafruit_ssd1306.SSD1306_I2C(128, 32, i2c, reset=reset_pin)
# Clear the display.
display.fill(0)
display.show()
width = display.width
height = display.height
# Configure RFM9x LoRa Radio
CS = DigitalInOut(board.CE1)
RESET = DigitalInOut(board.D25)
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
while True:
# Clear the image
display.fill(0)
# Attempt to set up the RFM9x Module
try:
rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, 915.0)
display.text('RFM9x: Detected', 0, 0, 1)
except RuntimeError as error:
# Thrown on version mismatch
display.text('RFM9x: ERROR', 0, 0, 1)
print('RFM9x Error: ', error)
# Check buttons
if not btnA.value:
# Button A Pressed
display.text('Ada', width-85, height-7, 1)
display.show()
time.sleep(0.1)
if not btnB.value:
# Button B Pressed
display.text('Fruit', width-75, height-7, 1)
display.show()
time.sleep(0.1)
if not btnC.value:
# Button C Pressed
display.text('Radio', width-65, height-7, 1)
display.show()
time.sleep(0.1)
display.show()
time.sleep(0.1)
To use the code, copy and paste the following command into your terminal:
python3 rfm9x_check.py
Now to check the setup:
If the RFM9x/RFM69 is detected, the OLED will display Detected. You can test the buttons by pressing them.
If the wiring of the radio module is incorrect - the display will show ERROR. Check over your wiring on the Wiring Page and re-run the test. You may also need to ensure the correct CircuitPython library is installed for the module.
If the OLED does not turn on - first check that it is wired correctly. Then, make sure you enabled I2C from raspi-config and installed the required libraries (adafruit-circuitpython-framebufand adafruit-circuitpython-ssd1306).
With everything working, let's move on to using the radio.
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