What is it
USE FOR https://www.pibot.com/cnc-laser-electronics/pibot-fluidnc-grbl-cnc-controller-v4-9
How it works
Connect1. Only 1 or 2 can be selected, one at a time, connected with a 0 ohm resistor.2. Option 1 is the onboard antenna mode (default)3. Choose 2 as IPEX external antenna
Spec..