====== Simple Raspberry Pi Control With .NET IoT and Python ======

Follow the “Prerequisites” and “Prepare the hardware” instructions [[https://docs.microsoft.com/en-us/dotnet/iot/tutorials/blink-led|here]]. (Note: These instructions specify .NET SDK 5 or higher. We’ll actually be using .NET 6.)

Assumes that you’re using Linux on your development machine as well.

===== .NET =====

On the development machine, create a console application:

<code bash>
dotnet new console -o BlinkTutorial

cd BlinkTutorial
</code>

Add the [[https://www.nuget.org/packages/Iot.Device.Bindings/|Iot.Device.Bindings]] package to the project:

<code bash>
dotnet add package Iot.Device.Bindings --version 1.5.0-*
</code>

Replace the contents of Program.cs with the following code:

<file csharp Program.cs>
using System;
using System.Device.Gpio;
using System.Threading;

Console.WriteLine("Blinking LED. Press Ctrl+C to end.");
int pin = 18;
using var controller = new GpioController();
controller.OpenPin(pin, PinMode.Output);
bool ledOn = true;
while (true)
{
    controller.Write(pin, ((ledOn) ? PinValue.High : PinValue.Low));
    Thread.Sleep(1000);
    ledOn = !ledOn;
}
</file>

Make sure the application builds without errors:

<code bash>
dotnet build
</code>

Publish it:

<code bash>
dotnet publish -c Release -r linux-arm --self-contained true /p:PublishSingleFile=true
</code>

Copy the application to the Raspberry Pi (adjust the remote machine name and path as needed):

<code bash>
scp -r bin/Release/net6.0/linux-arm/publish/* pi@raspi4-main:/home/pi/projects/BlinkTutorial
</code>

Log in to the Raspberry Pi, go to the publish directory, and run the application:

<code bash>
ssh pi@raspi4-main

cd projects/BlinkTutorial

./BlinkTutorial
</code>

Enjoy the blinking light!

Makefile, to simplify the steps:

<file make Makefile>
REMOTE_USER_MACHINE = pi@raspi4-main

default:
	@echo 'Targets:'
	@echo '  build'
	@echo '  publish'
	@echo '  copy'
	@echo '  ssh'

build:
	dotnet build

publish:
	dotnet publish -c Release -r linux-arm --self-contained true /p:PublishSingleFile=true

copy:
	scp -r bin/Release/net6.0/linux-arm/publish/* $(REMOTE_USER_MACHINE):/home/pi/projects/BlinkTutorial

ssh:
	ssh $(REMOTE_USER_MACHINE)
</file>

===== Python =====

Log in to the Raspberry Pi:

<code bash>
ssh pi@raspi4-main
</code>

Create a directory for the Python script:

<code bash>
mkdir blink_tutorial

cd blink_tutorial
</code>

Install the gpio packages:

<code bash>
sudo apt-get install python-rpi.gpio python3-rpi.gpio
</code>

Create the script:

<file python blinking_led.py>
#!/usr/bin/python3

import RPi.GPIO as GPIO
from time import sleep

gpio_pin = 18
pause_seconds = 1

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(gpio_pin, GPIO.OUT, initial=GPIO.LOW)

while True:
    GPIO.output(gpio_pin, GPIO.HIGH)
    sleep(pause_seconds)

    GPIO.output(gpio_pin, GPIO.LOW)
    sleep(pause_seconds)
</file>

Make the script executable, and run it:

<code bash>
chmod u+x blinking_led.py

./blinking_led.py
</code>

Enjoy the blinking light! (Again!)

{{tag>embedded_and_iot dotnet python}}