so ive been messing around with a raspberry pi zero w for a few months now trying to get it to handle some basic automation in my shack and honestly its going better than expected but also hitting some walls. the main thing i wanted was something that would watch my radio (ic-7300) via USB, log contacts automatically to my logging software, and maybe eventually trigger a relay to switch antennas based on band. the logging part is mostly working, im using hamlib and a python script i cobbled together from like four different tutorials.

the problem im running into is the zero w just kinda chokes when im also trying to run the web interface i set up to control it remotely. not crashing exactly, just sluggish in a way that feels like its gonna cause problems during a contest or something. was thinking about throwing an arduino nano in the mix to handle the relay switching separately so the pi isnt juggling everything. does that setup make sense or am i overcomplicating this? i know some people just use a full pi 4 for this stuff but i have like 6 zero w's from a kit i bought and id rather use what i have

yeah that makes total sense actually, the zero w is kinda underpowered for running a web server and doing serial comms at the same time, especially if youre doing any real time stuff. offloading the relay control to an arduino is exactly the right call imo. the arduino handles that kind of low level IO way more reliably and you dont have to worry about linux scheduler messing with timing. i2c between the pi and arduino works fine for something like this, or even just basic serial over UART if you want to keep it simple. ive got a similar setup controlling a bandpass filter bank, pi does all the logic and the arduino just executes relay commands. works solid.

one thing to watch, make sure youre using optocouplers between the arduino outputs and any relay coils, especially if theres any chance of RF getting into the control lines. learned that one the hard way during a field day a couple years back, had a relay go haywire every time i keyed up on 40m.

im running almost the same thing but with a pi 3b+ and honestly even that feels a bit heavy sometimes for the shack automation stuff. your plan with the nano sounds fine, i think people overcomplicate the pi/arduino question -- they're just tools and mixing them is totally normal. the arduino is better at doing one thing reliably, the pi is better at the networky web stuff.

side note, have you looked at flrig for the rig control piece? it plays nice with hamlib and might save you some scripting headaches depending on what youre actually trying to do with the 7300