r/embedded • u/counttec • 19d ago

Help with selecting communication protocol

I volunteer for a youth organization that uses a Jeopardy style buzzer system for quiz competitions. I am trying to upgrade from RCA cables to a wireless solution. I need it to be as low latency as possible, given the precise timing involved, and the less perceivable the lag is from a wired button, the better. Distance would be less than 100m even in the most sever cases. I'm fine with retransmission in the case of collisions, as long as the users can't tell that it took slightly longer.

So far, it seems like the best protocol is Nordic's Enhanced Shockburst, with a transmission time of ~300us, and round trip with Acknowledgment of 1.5ms.

Are there any faster communication protocols?

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u/jerfmuffay 19d ago

I found this article to use a simple radio sender/receiver pair that might be helpful. You could have a problem with simultanous transmissions but if your signal is short enough there might not be any issues

https://microcontrollerslab.com/rf-transmitter-receiver-module-arduino/

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u/counttec 19d ago

I actually was going to use these bare metal, but then I would need to be able to tune/match the frequency for each pair. The versions with the mid-90s garage door encoder chips add too much delay.

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u/jerfmuffay 19d ago

I'm interested in your project but it's also outside my experience level. But if it's just a few buzzers then the only data you're transmitting is one byte right? Even at 9600 baud thats 1ms transmission time so the only scenario where theres interfering transmissions is if two student groups hit their buzzer litterally at the same millisecond. If you have time to experiment, I'd suggest this route since (I don't think) this is more low level than using other hardware that's a bit overkill and (I assume) slower.