so i've been messing around with a raspberry pi zero w for about 3 months now trying to get it to handle some basic shack automation stuff and honestly i dont know if im making this harder than it needs to be or if this is just how it is

the basic idea was to have it monitor my IC-7300's band activity via rigctld, then automatically kick on the amp and switch the antenna relay depending on what band i qsy to. seemed simple enough on paper. i got rigctld talking to the radio fine, python script is reading the frequency, but the GPIO side is where things keep getting weird. the relay board im using is one of those cheap 4-channel jobs off amazon and it seems like whenever the pi is under any load at all the relay timing goes wonky. like it'll fire 200-300ms late sometimes which isnt the end of the world but it means the amp is keying before the antenna is fully switched and i can hear it in the audio

ive tried moving the relay control to a separate thread, tried a small arduino nano as a dedicated relay controller communicating over serial from the pi, that actually helped a lot but now im dealing with occasional serial dropouts and i feel like im just adding complexity to fix complexity

anyone else running a setup like this or am i reinventing the wheel when there's already some smarter way to do it

yeah the timing issue with relay boards and the pi is a known headache, the OS scheduler on raspbian just isnt real-time so you'll always get that jitter under load. the arduino as dedicated relay controller is actually the right move honestly, most people end up there eventually. the serial dropout thing though — are you using hardware serial or the software serial library on the arduino side? software serial is garbage above like 9600 baud and even then it can get flaky. if youre on an uno or nano just make sure youre on the hardware UART pins and use a reasonable baud rate, 115200 should be fine. also double check your ground reference between the pi and arduino, ive seen weird serial issues that were just a floating ground between the two boards

the other thing id look at is whether your relay board is pulling more current than the pi GPIO can handle cleanly. some of those boards need a separate 5v supply for the relay coils, if youre powering the coils off the pi's 5v rail thats probably causing noise on the logic side too

i went down basically the exact same path a couple years ago trying to automate antenna switching for my 6m setup. ended up ditching the pi for that specific task and just using a standalone arduino mega with a ethernet shield so i could throw a simple web interface on it and control everything from any browser in the shack. way less moving parts than dealing with linux and rigctld and all that. pi is great but for something that just needs to flip relays reliably it feels like overkill sometimes

that said if you want to keep the pi in the loop the nano as a coprocessor idea isnt bad, lots of commercial stuff basically does the same thing with a microcontroller handling the timing-critical stuff and a bigger processor handling the logic. just gotta get the serial comm solid