so ive been messing around with a raspberry pi zero w for a few months now, mostly just hobby stuff, but i finally got around to trying to tie it into my shack setup. the idea was pretty simple - i wanted something that would automatically pull my adif log from WSJT-X over the network and then cross-reference it against a couple of award tracking spreadsheets i keep, and then push alerts to a little 16x2 LCD when i work a new state or DXCC entity. seemed straightforward on paper.

anyway i got most of it working but the part thats killing me is the serial communication between the pi and my IC-7300. im using a cheap CH340 USB-to-serial adapter and the pi keeps either not seeing the port at all on reboot or assigning it a different device name like ttyUSB0 one time and ttyUSB1 another and it just breaks whatever script i had running. ive tried writing udev rules to lock it to a persistent name but honestly i followed three different tutorials and they all contradict each other so im not sure i did it right.

also thinking about adding an arduino nano to handle the LCD side of things since the pi's GPIO at 3.3v is kinda annoying to work with when most of the I2C display modules want 5v and i dont want to mess with level shifters everywhere. not sure if thats overengineering it or just practical. anyone gone down this road with similar gear?

yeah the udev rules thing is a pain the first time but once you get it right it just works forever. the key is you need to match on the serial number of the USB device, not just the vendor and product ID, because if you ever plug in two CH340 devices they'll have the same VID/PID and it won't help you at all. run udevadm info -a -n /dev/ttyUSB0 while the rig is plugged in and look for the ATTRS{serial} line. if the CH340 actually has a serial number burned in (some of the cheapo ones dont) use that. if not you might need to match on the physical port location instead with KERNELS which is a bit fragile if you ever change which USB port you use.

for the arduino/pi split i do exactly what you're describing on my shack automation box. pi handles all the logic and network stuff, arduino mega handles anything that needs reliable real-time GPIO or 5v signaling. way less headache than fighting level shifters everywhere and the I2C between them is only like 18 inches of wire so no issues there. the nano might be a tight fit memory wise if you want to do anything fancy with the display strings but for basic LCD output its fine.

i did something similar a while back, different radio but same general idea. one thing i'll throw out - have you looked at flrig as a middleman for the CAT control instead of going straight to the serial port from your script? that way flrig holds the port open and your pi script just talks to flrig over its XML-RPC interface on localhost. eliminates the whole device naming problem and you can even share rig control with multiple programs at once which is nice if you're running wsjtx and something else simultaneously.

also just curious what you're using for the adif parsing, doing it yourself or using a library? i tried rolling my own parser once and deeply regretted it when i hit some edge cases in how different logging programs format their records.