so ive been sitting on this idea for a while and finally started messing around with it last weekend. basically i have a 4 port coax switch (the manual kind, nothing fancy) and im trying to figure out if i can drive the relays off an arduino uno so i can switch antennas from the shack PC instead of walking over to the shelf every time.

i've got some basic arduino experience from a few years ago, made a keyer once that kind of worked, and i know enough to not blow up a pin with too much current. my plan is to use a relay board, the 4 channel ones you can get off amazon for like $8, and just trigger each relay with a digital output pin through a simple transistor stage or maybe just direct if the relay board has the optocouplers built in.

the part im not sure about is the software side. i was thinking a raspberry pi zero w might actually be better for this because then i could just hit it over wifi from any computer in the house or even my phone and not have to mess with USB serial every time. has anyone gone down this road? curious if theres a simpler approach im missing or if this is basically the right way to do it.

yeah done something pretty similar for my HF station about two years ago. ended up going the pi zero W route for exactly the reason you said — wifi just makes it so much easier, especially since you can throw a simple flask web server on it and control everything from a browser. took me maybe an afternoon to get something basic running once i had the GPIO wiring sorted.

the relay boards with built-in optocouplers are definitely the move, saves you from worrying about the inductive kick from the relay coils frying your GPIO pins. most of those cheap chinese boards work fine, just double check the trigger logic — some are active low which trips people up at first. one thing i'd add is put a small cap across each relay coil anyway even with the opto, i had one board where the protection was kind of marginal and i was getting weird resets under RF. might have been a grounding thing too honestly, hard to say.

for the control side i just wrote a tiny python script and served it with flask, nothing fancy. you can also look into node-red if you want something more visual without writing as much code, works well on the pi zero.

dont overthink the software side of it, i'd just go arduino with a cheap ESP8266 or ESP32 instead of the pi zero. less moving parts, boots in 2 seconds, no SD card to corrupt, and the wifi is built right in. you can serve a simple html page straight from the chip. i use an ESP32 for a bunch of shack automation stuff now and honestly its replaced the pi for anything that doesnt need real computing power.