bjarne-hansen / py-nrf24

Library for NRF24L01 communication using pigpiod on Raspberry Pi.
MIT License
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arduino communication electronics iot nrf24l01 pypi python raspberry wiring

NRF24L01 for Python

This package implement 2.4Ghz communication using NRF24L01+ modules on a Raspberry Pi using Python.

Changes

Background

The code is based on a modified version of some example code found on StackExchange. The author of the original code is also the author of the pigpio library found here http://abyz.me.uk/rpi/pigpio/.

I have obtained the original authors approval to modify and distribute the code anyway I want. So, I have created a very basic Python package and published it on PyPI under a MIT license.

The nrf24 packages depends on the pigpio package that is available via PyPI as well. Before installing and running any of the code and examples below, please make sure you the pigpid daemon running on your Raspberry. This is a library/server that provides access to the GPIO ports of the Raspberry.

Details avalable at http://abyz.me.uk/rpi/pigpio/download.html

Quick installation of pigpio on Raspbian:

sudo apt-get update    
sudo apt-get install pigpio python-pigpio python3-pigpio

Installing

You may want to create a virtual environment before installing the nrf24 package which depends on the pigpio package.

$ pip install nrf24

Examples

All examples in the test folder can be run as command line programs. They all take optional command line arguments to specify the hostname (default: localhost) and the port (default: 8888) of the pigpio deamon. Most of them also takes one or more addresses to use. All should have sensible defaults, so running them without arguments should be an OK first approach to testing your setup.

All test have been run on a Raspberry Pi 4 and a Raspberry Pi Zero Wireless equipped with 2 x NRF24L01+ modules each.

The int-sender.py and int-receiver.py examples requires extra wiring connenting the IRQ PIN of the NRF24L01+ module to a GPIO on the Raspberry. This wiring is shown in "Raspberry Pi with Single NRF24L01+ Module (IRQ)".

The multi-sender.py and multi-receiver.py examples requires two NRF24L01+ modules. The wiring for that setup can be seen in "Raspberry Pi with Dual NRF24L01+ Modules" below.

The rest of the Raspberry Pi examples runs with the IRQ wiring as described above, or a simpler wiring like the one shown in "Raspberry Pi with Single NRF24L01+ Module" below.

Command Line Comments
python test/simple-sender.py Emulates a process sending sensor readings every 10 seconds using a dynamic payload size (default sending address is 1SNSR).
python test/simple-receiver.py Emulates a receiving process receiving sensor readings from the corresponding sender using a dynamic payload size (default listening address 1SNSR).
python test/fixed-sender.py Emulates a process sending sensor readings every 10 seconds using a fixed payload size (default sending address is 1SNSR).
python test/fixed-receiver.py Emulates a receiving process receiving sensor readings from the corresponding sender using a fixed payload size (default listening address 1SNSR).
python test/mixed-sender.py Shows an example of sending both fixed and dynamic payload sized messages. Suggested address for fixed messages is FTEST, and the suggested address for dynamic messages is DTEST.
python test/mixed-receiver.py Shows how to configure reading pipes using both fixed and dynamic message sizes at the same time.
python test/int-sender.py Shows how to use interrupt to detect that a message has been sent (default sending address 1SNSR).
python test/int-receiver.py Shows how to use interrupt to detect that a message has been received (default listening address 1SNSR).
python test/rr-client.py Shows example of how to send a request to a server with a reply to address included in the message, and then switching to RX mode to receive the response from the server (default server (TX) address is 1SRVR and default reply to address (RX) is 1CLNT)
python test/rr-server.py Shows example of a server listening for requests and returning a response to the client (default server (RX) address is 1SRVR).
python test/ack-sender.py Sends message to the receiver every 10 seconds, expecting a payload sent back with the acknowledgement (default sender address 1ACKS).
python test/ack-receiver.py Receives message and sends acknowledgement message with payload (default listen address 1ACKS).
python test/multi-sender.py Sends messages using 2 x NRF24L01+ modules connected to the same Raspberry Pi (defult send addresses 1SRVR and 2SRVR).
python test/multi-sender.py receives messages using 2 x NRF24L01+ modules connected to the same Raspberry Pi (defult listen addresses 1SRVR and 2SRVR).

If you do not have multiple Raspberry Pi computers, you can run some of the test programs on Arduino. In the arduino/ directory are sender programs equivalent with some of those described above. The wiring for the Arduino Nano can be seen in "Arduino Nano with DHT22 and NRF24L01+" below. Unlike it's Raspberry Pi counterparts the Arduino examples have been done with an actual DHT22 sensor connected so that we do not need to emulate sensor readings.

Arduino Code Comments
arduino/simple-sender Sends temperature and humidity readings to the simple-receiver.py counterpart.
arduino/fixed-sender Sends temperature and humidity readings to the fixed-receiver.py counterpart.
arduino/mixed-sender Sends temperature and humidity readings to the mixed-receiver.py counterpart.
arduino/rr-client Executes request/response calls against its rr-server.py counterpart.
arduino/ack-sender Sends temperature and humidity readings to the ack-receiver.py counterpart and receives acknowledgements with payload.

Wiring

Raspberry Pi with Single NRF24L01+ Module (IRQ)

Raspberry Pi with Single NRF24L01+ Module (IRQ)

Raspberry Pi with Dual NRF24L01+ Modules

The multi-sender.py and multi-receiver.py examples requires two NRF24L01+ modules wired to each Raspberry Pi.

Raspberry Pi with Dual NRF24L01+ Modules

Raspberry Pi with Single NRF24L01+ Module

All the examples, except the multi-sender.py, multi-receiver.py, int-sender.py, and int-receiver.py ones will run with the following wiring of a single NRF24L01+ module.

Raspberry Pi with Single NRF24L01+ Module

Arduino Nano with DHT22 and NRF24L01+

The Arduino examples in arduino/ can all run with the following wiring.

Arduino Nano with DHT22 and NRF24L01+