B4J Question How to use PI4J 2.4.0 library?

[Asdominik]

Hello, i search a library to power on and read on GPIO pins on Raspberry PI 4B.
I found and downloaded the PI4J 2.4.0 library in a zip file on the forum. When I unpack the zip on the PC, I get two folders lib and bin. When I copy them to the Library folder, the desired library is not displayed in the list of libraries.
I am using B4J v.10 application. I'm doing something very wrong but I can't get out of the problem. The bridge works fine as does the app itself on the Raspberry PI.
I only need this GPIO control addon.

Could someone help me step by step how to install and use PI4J library.

Thanks,

 

[hatzisn]

I could not get it to work either. I have found though a solution. You do not need the library. You can use terminal commands with jshell to set a pin HIGH or LOW. There is a terminal command but I do not remember it now (google it). Obviously this is not for i2c etc unless you want to get too technical but if you just want to send a HIGH/LOW signal to a GPIO pin it suits you perfectly...

 

[Cableguy]

Do note that, as in arduino, the pins are not referenced by pin number, but by reference, like A1 (analog 1) or sda1... you need to cross reference them

 

[Asdominik]

Thanks for the reply.

I can't get to the bottom of the matter either.

I saw a solution via the jsheel command directly on the Rapsberry PI, which works for me to turn the pins on and off. But I also have two pins configured as input where I would monitor the state of the inputs. And I have no idea how to do it via jshell command.

One solution is to use a py script, which I also call via jshell and enables switching certain pins on and off, as well as monitoring inputs. But I have to test both variants and I'll see how it works out.

I will let you know how both variants work.

 

[walterf25]

I have wrapped the I2C functions and work just fine on Raspberry Pi 4B, if I have some time I can try to expose all the other methods such as controlling GPIOs etc.

Walter