What is the 4 pin header?

[atchoo78]

Hi,

I just noticed that there's a 4 pin mystery header on the PCB hardware "blueprint" and even on all the pictures in the manual. However, it's not there on my board 😆 , and I can't seem to find any info on its purpose and what it's supposed to connect to. Am I missing out on anything?

[jamesbowman]

That's a picture of an early prototype. That is the development header for the onboard EFM8BB1 microcontroller. The header was removed from the production design.