Setting up a Pi 4 as a dedicated contest automation controller to interface with my main Windows N1MM+ logging station. Goal is to handle antenna switching (SteppIR controller), band following for amplifier, and automatic recording of audio for later review.

Using Ham-Pi distribution with additional Python scripts for serial control of antenna controller and RF switching matrix. FLRIG handles CAT control of the IC-7610, works perfectly with N1MM+ via TCP/IP.

The trickiest part has been getting reliable PTT timing — there's about 50ms delay in the chain that's causing issues with voice keyer timing in rapid-fire contest exchanges. Anyone solved similar latency problems in Pi-based automation systems?

Also wondering about best practices for integrating GPIO-controlled relay drivers with contest software timing requirements.

For contest timing, bypass software PTT and use hardware VOX or direct relay control. I trigger PTT via GPIO immediately when audio starts rather than relying on CAT commands. Much faster response.

That 50ms delay sounds like audio buffering in ALSA. Try reducing buffer sizes in your audio config — I got it down to 10ms with proper tuning. Also consider real-time kernel for better timing precision.

I'm just getting into contesting and this sounds amazing! Are you planning to share the Python scripts? Would love to learn how you're handling the antenna switching logic — do you have automatic band plans programmed in?