PINs for Wifi Cyan LED on Photon?

[rickkas7]

I just wrote this tutorial on using Serial2, but it also explains both options: how to access the pins on the bottom for using an external RGB status LED, and also how to redirect the LED in software to other pins.

Using Serial2 on the Photon

Normally, the Photon has one UART hardware serial port (Serial1) and the USB serial port (Serial). There is another hardware UART serial port (Serial2), but getting to it is a pain. I don’t recommend using it. Serial2 shares the same pins as the RGB status LED. This means that you have to disable to status LED. This will make debugging a pain in the future. If your code is running, you can mirror the status LED on another LED. Unfortunately that doesn’t work when your code is not running, which…