Installing .NET 6 on Raspberry Pi 4 and get CPU temperature via C#

How to setup .NET 6 on Raspberry Pi? Basically, it is just the same as what we have been done for .NET 5. The first thing you need to confirm is whether your Raspberry Pi is the 32-bit (current official version) or 64-bit (official beta) version. Please run the command below to check the version.

uname -a 

# Linux raspberrypi 5.10.60-v8+ #1449 SMP PREEMPT Wed Aug 25 15:01:33 BST 2021 aarch64 GNU/Linux
# Linux raspberrypi 5.10.17-v7l+ #1421 SMP Thu May 27 14:00:13 BST 2021 armv7l GNU/Linux

If the result is aarch64 GNU/Linux then you are using 64-bit OS, meanwhile armv7l GNU/Linux will be 32-bit OS. After confirmed the Raspberry Pi 32/64 bit version, let us head to Microsoft .NET website to download .NET 6 (https://dotnet.microsoft.com/download/dotnet/6.0). Please note as per current date, .Net 6 is in release candidate version.

We just need to download the SDK only if we want to build apps using .NET, the runtimes are already included inside the SDK. Arm32 is for 32-bit OS and Arm64 is for 64-bit OS, please download the correct version for yourself. You can download by clicking the link or you can use the wget command to download. E.g. if download the .NET 6 RC1 Arm32 binary.

wget https://download.visualstudio.microsoft.com/download/pr/5156a2cf-157d-4517-afb9-766699df8b74/077a3e0570f64d72ee2d2c72dd6b9c80/dotnet-sdk-6.0.100-rc.1.21458.32-linux-arm.tar.gz

After the download is completed, extract the downloaded file to $HOME/dotnet folder and set using export command so you able to execute the dotnet command from current session Terminal.

mkdir -p $HOME/dotnet && tar zxf dotnet-sdk-6.0.100-rc.1.21458.32-linux-arm.tar.gz -C $HOME/dotnet
export DOTNET_ROOT=$HOME/dotnet
export PATH=$PATH:$HOME/dotnet

If you want to permanently add the export command to the shell profile, so you don’t need to re-key in the export every time you log in Raspberry Pi or open a new Terminal, then you need to copy the commands to .bashrc.

# Run nano editor to edit the .bashrc
nano ~/.bashrc

# Copy the commands below to the .bashrc
export DOTNET_ROOT=$HOME/dotnet
export PATH=$PATH:$HOME/dotnet

# Run this command so the terminal session will use the new settings
source ~/.bashrc

After all setup have been done, run dotnet --info to verify your installation, you should get some thing like below:

Then, we can try to develop a .NET 6 get Raspberry Pi CPU temperature console app in Raspberry Pi now. Run the command below to create a dotnet new console app and switch to that folder once done:

dotnet new console -o GetCpuTemperatureOnPi && cd GetCpuTemperatureOnPi

You can execute dotnet run now if you want, you will get a Hello, World! message. To get the Raspberry Pi CPU temperature, we need to use System.Device.Gpio and Iot.Device.Bindings packages. Run the command below to get them from nuget.org (a .net package repository).

dotnet add package System.Device.Gpio
dotnet add package Iot.Device.Bindings 

After added, run nano Program.cs to edit the source code. Delete all the code inside and copy the code below to get the CPU temperature.

using System;
using System.Threading;
using Iot.Device.CpuTemperature;

using CpuTemperature cpuTemperature = new CpuTemperature();
Console.WriteLine("Press any key to quit");

while (!Console.KeyAvailable)
{
    if (cpuTemperature.IsAvailable)
    {
        var temperature = cpuTemperature.ReadTemperatures();
        foreach (var entry in temperature)
        {
            if (!double.IsNaN(entry.Temperature.DegreesCelsius))
            {
                Console.WriteLine($"Temperature from {entry.Sensor.ToString()}: {entry.Temperature.DegreesCelsius} °C");
            }
            else
            {
                Console.WriteLine("Unable to read Temperature.");
            }
        }
    }
    else
    {
        Console.WriteLine($"CPU temperature is not available");
    }

    Thread.Sleep(1000);
}

Run dotnet run again, and you will get the result like below:

Lastly, please do note you can edit the .NET project and C# source code using Visual Studio Code, which provides a better experience if compare to using Nano. Hope you will learn something new today, Happy Coding :).

Reference:
https://github.com/dotnet/iot/tree/main/src/devices/CpuTemperature