The Industrial Raspberry Pi Forum

I’m currently developing a C++ application that needs to control the output pin states of a RevPi DIO module connected to a RevPi Connect 5. The program runs directly on the RevPi Connect 5 under **Bookworm** (Debian GNU/Linux, kernel `6.6.0-revpi8-rpi-v8`).

Ideally, I’d like to use the symbolic pin names defined in the PiCtory process image (e.g. `"O_1"`) directly in my C++ code to set pin states. From the available documentation and prior discussions (including some with ChatGPT), this appears to be supported via the **`revpi-dev`** package, which provides headers such as `piControlIf.h` and the corresponding shared library (`libpiControl.so`).

However, I’ve been unable to locate `revpi-dev` (or any alternative development package providing those headers) in the Bookworm repositories. Could you advise on:

* How to obtain the necessary headers and libraries for **Bookworm**?
* Whether there is a **newer/recommended API** for accessing named pins in C++ on recent RevPi systems?

As a temporary workaround, I’m using:

```cpp
std::string cmd = "piTest -w " + identifier + "," + (state ? "1" : "0") + " > /dev/null 2>&1";
std::system(cmd.c_str());
```

—but this relies on `std::system`, which spawns a shell process for every call and is not ideal for production use.

Any official guidance or workarounds would be greatly appreciated!

Hi,

unfortunately that's made up by chatpt: there is no such thing like revpi-dev or libpiControl.so. Nevertheless you can find a C example of how to access the process image here https://gitlab.com/revolutionpi/revpi-pitest/ (should be relatively easy to transfer this to c++. It also includes the header file you have mentioned: https://gitlab.com/revolutionpi/revpi-p ... type=heads

Nicolai

Thank you for your response. Am I correct in my understanding that the repository you linked is the source for the `piTest` command on the RevPi?

Further, would I need to simply copy the files `piControlIf.c` and `piControlIf.h` into my project, and then use the functions they expose to update pin states?

Yes, this is the source code of the piTest application on your RevPi. The includes can be re-used for your application too. In the piTest source you can have a look which functions / how it does work.

Thank you, I have now managed to integrate this into my application.