so ive been messing around with an arduino mega for the past few weeks trying to get it to handle antenna switching and also trigger my logging software when i key up. the antenna switching part works fine, got a bunch of relays on a board i etched myself and the arduino just reads the band data from my 7300 via CI-V and switches accordingly. that part was honestly easier than i expected.

the logging integration is where im losing my mind a little. im running N1MM and i know it puts out UDP packets but parsing those on the mega is kind of a pain because the string handling on these things is just not great. im wondering if anyone has bridged this with a Pi instead — like put the Pi in the middle to do the heavy lifting on parsing and just send simple commands down to the arduino for the relay control. seems like overkill but maybe thats just how it has to be done

also my relay board is getting warm which is probably fine but wanted to mention it in case someone tells me thats actually not fine

yeah the pi in the middle approach is exactly what i ended up doing after trying to wrestle with string parsing on an uno for way too long. the mega is better but honestly python on a pi zero just handles all that UDP and serial stuff so much more cleanly. i wrote a little script that listens for N1MM broadcasts, pulls the freq and mode out, and sends a two-byte command over serial to the arduino which just does a lookup table for which relay combo to fire. works solid, been running it for like 8 months with one reboot for a power outage.

the warm relay board thing — depends on what relays you're using and what voltage youre switching. if theyre just coax relays for HF and the coils are rated right it should be fine. if it's warm to the touch but not hot i wouldnt worry. if you can smell anything or its uncomfortably hot to hold your hand near, id check your coil voltage and make sure you have flyback diodes on all of them because without those the arduino pins will get cooked eventually even if it seems fine now

i did something similar-ish but way more janky lol. just used a pi 4 for everything including the relay driving through a ULN2803 chip, skipped the arduino entirely. worked until i somehow fried two of the GPIO pins and then spent a weekend figuring out why relay 3 and 6 stopped responding. not saying dont do it that way but the arduino as a dedicated IO controller is probably smarter just for the isolation