Direct addressing of GPIO board
Does anyone know or have figured out the I2C address for this board?
I have a number of these (4) and would like to utilize outside of the Mk3/4/C1 environment.
Thank you...
RE: Direct addressing of GPIO board
So if anyone is interested, I ran a serial scanner on the GPIO board. Turns out the address is 0x20. It responds nicely to commands from a RPi.
Now to find some use for it!
RE: Direct addressing of GPIO board
Additional info for anyone interested. The chip in question is a TCA6408ARGTR, and here is the link to the datasheet on TI's website (link copied from the DigiKey product page):
That should give you all the commands. There is an ADDR pin (pin 16) that on the I/O board is tied to ground. I don't have physical access to the board to see how Prusa did it, but if there is an accessible trace that can be cut and you are able to tie that pin to the VCC of the chip (3.3VDC) then the address will change to 0x21 and you could have two of these boards on the same I2C bus without any extra chips (like an I2C multiplexer). Would have been nice for Prusa to run that pin to a jumper where the user could easily change the address to allow two I/O boards on one printer, but I don't see any indication of that on the schematic. I have a suspicion that Prusa just tied that pin to the same copper fill that the middle pad is soldered to. In that case, there would be no way of isolating pin16 without SMT rework.
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE: Direct addressing of GPIO board
Good info - you do have one area where you can cut the trace, or sever the leg at the solder pad. Tricky but can be done. I'd load the picture but for some reason the 'add media' button doesn't work...