Hello @Embring - thank you for your comments, those are greatly appreciated.
As for the I2C communication: I have never tried taking from the Raspberry Pi to an Arduino (“slave”) over I2C. That said, this should work, so I’d be happy to help you debug this issue and make the necessary changes to the Hardware I/O library to support this.
The the read() method tells the kernel driver (via the I2C_RDWR ioctl) to read in the given number of bytes from the previously opened I2C device handle.
Do you have this type of communication working in any other programming environment?
Could you upload sketches for both Pi, as well as Arduino for me to test?