I am trying to build a simple LED strip driver with 2 PIR's on it. I created a little prototype board with some mosfets and a buck converter to go from 12v to 5v. The PIR sensors also need 5V so I thought it made sense to use that.
So eventually I want to hoop up a 12V power supply, so I won't be powering the Wemos through the USB connector.
I read about the pins that define how the wemos should be booted. So I connect D3 and D4 to 3.3V to have these pins high, and D8 to GND to have this low. This should enable boot from flash right?
I have tried three different Wemos board but they all won't boot. If I connect them with the usb cable everything is fine, esphome is started, to problem. But as soon as I want to use the external power supply it's all quited.
I measured between 5V and G on the wemos as well as D3 and G and D4 and G. All voltages seem to be good.
So what am I missing? Why wouldn't it boot?