I am waiting for my PCB to arrive. In the meantime, I want to test as much as the firmware that I made as I can. I am using 4 MUXs (TCA9548A) and a raspberry Pi, the slave devices are interchangeable via screw terminals. Does anyone know of possible simulators that don’t cost an arm or a leg or if this is even possible to do?

Any recommendations for would be great. I have done research online, but I haven’t seen anything yet. Even if I can only test part of my code, that would be great.