Author Options:

can GPIO pins be used to communicate with a processor? Answered

I would like to know just curious as I would like to communicate with a ARM CPU (or more powerful processor) by using a GPIO expansion board plugged into a raspberry pi's GPIO.



4 years ago

its possible to use / create a software SPI interface that doesn't rely on the microprocessor actually having a hardware SPI interface. Checkout http://www.libstock.com/projects/view/105/software-version-max7219-seven-segment-wrapped-library for example C code on a PIC micro that actually does this.

no the site is nothing to do with me but it is a cool way of doing things if the hardware is lacking.

Ok well I lack both hardware and software skills when it comes to CPUs and processors in general

Yes, it would be entirely possible to use the SPI bus pins on the Pi to talk to an ARM

Do you have any info because I am interested... I would like to know where the SPI pins are. also would like to know how to possibly go about doing this. I am not good with circuits yet so I would need help with that.

Its a very advanced thing to try if you don't know how to handle circuits. The GPIO connectors are clearly marked here.


I have a cousin who is very good with computers and I also have the raspberry pi forums. but in the end I will need to design a circuit.

Get one of the standard I/O boards for the Pi, they'll begin to teach you about SPI.