Hi, in your picture, the "PP" means most likely "PE", which is the protective earth, and the ground of both modules. According to the data sheet (https://www.codico.com/de/yellow-beet-e-1-1) the yellow beet does not have a PP (proximity pilote).
So I assume you connected the ground to ground, and ...

johu wrote: ↑Tue Aug 27, 2024 7:36 am Are the two modules on a common GND / PE?

EDIT: took the liberty to replace your google doc with an attachment. Linked docs have a tendency to disappear

Yes, I use the power supply for the microcontroller from my computer

I am researching about electric vehicle charging station (EVSE), I bought 2 Yellow beet boards from Codico (https://www.codico.com/en/yellow-beet-e-1-1) These 2 boards are based on Qualcomm QCA7K, actually I had problems with them because both boards have the role of EVSE, but after sending a mail ...