This shows how to run the tests on a Raspberry Pi. On other platforms, things should be similar.

(to be extended)

First, clone the repository on the pi:

git clone https://github.com/dotnet/iot
cd iot

Now you can

• Either download and install the NET Core SDK from https://get.dot.net/ (the Raspberry Pi with the default 32 Bit Raspbian Linux requires the ARM32 version) or
• run ./build.sh in the checkout directory. This will install the correct NET Core SDK in the .dotnet subfolder of the working copy.

Build System.Device.Gpio.dll:

cd src/System.Device.Gpio
dotnet build System.Device.Gpio.sln

This builds the main System.Device.Gpio assembly together with its test assembly. Before running the tests, you need to:

• Connect BCM Pins 12 and 16 (physical Pins 32 and 36) with a cable. It is suggested to add a 1kΩ to 10kΩ resistor between the pins; this protects the Pi in the case of a misconfiguration (i.e both pins set to Out, one high, the other low).
• Leave BCM Pin 23 (physical Pin 16) open (not connected to anything).

After that, you can run the tests with the RaspberryPiDriver (which is the default low-level driver for the Raspberry Pi) like:

dotnet test --filter RaspberryPiDriverTests System.Device.Gpio.sln 

Depending on the version of the Pi and the installed Linux distribution, it may be required to run the tests as root:

sudo dotnet test --filter RaspberryPiDriverTests System.Device.Gpio.sln 

If everything went smoothly, the output should end with a success message.

Alternatively, you can run the tests using the xunit console runner, which allows for better control of what should be executed (see the next section).

XUnit.console.runner is installed as a nuget package on the system in your home directory during the build. From the root of the project directory, execute:

pi@raspberrypi:~/projects/iot $ dotnet exec ~/.nuget/packages/xunit.runner.console/2.4.1/tools/netcoreapp2.0/xunit.console.dll artifacts/bin/System.Device.Gpio.Tests/Debug/netcoreapp3.1/System.Device.Gpio.Tests.dll -notrait "SkipOnTestRun=Windows_NT" -notrait "feature=i2c"

This runs the tests excluding the I2C tests (-notrait "feature-i2c") and excluding the Windows tests (-notrait "SkipOnTestRun=Windows_NT").

Currently the full test suite requires following components, if you don't have one use following command line switches to skip (for the full command line, see above)

• Also inputs to ADC are required including one connected to PWM output through low pass filter, please refer to the schematics.

You can also run the SysFsDriver Tests (this uses a more generic approach). This driver requires root permissions to run, so you need to sudo the command:

sudo dotnet test --filter SysFsDriverTests System.Device.Gpio.sln 

To run the Libgpiod Driver test (a Linux Kernel Driver for the GPIO device), you need to first install the libgpiod package:

sudo apt install -y libgpiod-dev

These tests do not require root permissions to run:

dotnet test --filter LibGpiodDriverTests System.Device.Gpio.sln 

Our CI is currently using this schematics with Raspberry PI 3.

You can download gerber files if you'd like to manufacture PCB yourself (this is a 2 layer board).

Following list of components are needed for PCB:

All headers are standard 2.54mm headers. Male headers are usually sold longer and are breakable to size.

/boot/firmware/config.txt

# Enable I2C, SPI, PWM

dtparam=i2c_arm=on
dtparam=spi=on
dtoverlay=pwm-2chan