so ive been messing around with a raspberry pi zero w for a few months now trying to get it to handle some of the tedious stuff during contests. right now im running it headless and using a python script to pull data off my IC-7300 via the USB-serial connection, basically reading the frequency and mode and then pushing that into a simple sqlite database. nothing fancy yet but it works most of the time.

the part thats giving me grief is the timing. during a pileup things get hectic and the script sometimes drops a line or gets behind and i end up with duplicate entries or missed contacts. i think its a threading issue but honestly my python is only decent, not great. ive looked at asyncio a little but havent gone down that rabbit hole yet.

also thinking about wiring up an arduino nano as kind of a middle layer to handle the keyer input separately so the pi isnt trying to do too much at once. has anyone actually done something like this where the arduino handles the low latency stuff and the pi handles the logging and network side? curious if thats overcomplicating it or if thats actually the right way to split the work.

yeah ive done something similar with a pi 3B and a nano working together for a WSPR beacon a while back. the split you're describing actually makes a lot of sense — arduino is way better for anything timing critical, like keying or PTT, because the pi's linux scheduler just isnt deterministic enough. you'll get random 10-50ms jitter from the OS doing whatever it wants and that kills you for CW or anything that needs tight timing.

for the logging side the threading issue might just be that youre not using a queue properly. i had the same problem. what fixed it for me was putting a thread-safe queue between the serial reader and the database writer so they never block each other. the reader just stuffs things in the queue as fast as it can and the writer pulls from it at whatever pace it needs. dropped my duplicates to basically zero. look up the queue module in python if you havent, its pretty straigthforward once you see an example.

not done the contest logging thing specifically but i use a pi 4 for rig control and a small arduino mega handles all my antenna switching relay logic. works great and honestly once you get the serial comms figured out between them its not that complicated. i use a really simple byte protocol, just send a command byte from the pi and the arduino acks it, nothing exotic.

one thing to watch with the zero w specifically — the wifi on it can cause weird timing hiccups if its doing a lot of network traffic at the same time as the serial stuff. ran into that. might be worth disabling the wifi power management mode, theres a simple command for it. or just use ethernet with a little adapter if your setup allows it.