I treid to use GPIO4 as an interrupt input. Just configuring it as an input, and connecting a switch and a pull-up resistor (100k) increased the power consumption from around 25uA to around 25mA.
I’m using GPIO1 now instead, and everthing seems fine, but I’d like to know why I had the problem with GPIO4, as I wasted a lot of time.
Are there any other GPIO pins to avoid?
Just me being an idiot. GPIO4 is the serial input to the RGB LED.
There seems to be an issue in the documentation. GPIO4 and GPIO5 is swapped on the board compard to the docs. From bottom to top it should be RST, GPIO4, GPIO5, GPIO0, SDA, …
Look at this topic
Or this github issue
In my case, it was just me being an idiot, and forgetting that GPIO4 was the serial in to the LED.
Nothing to do with incorrect labelling…
On https://heltec.org/project/htcc-ab01/ there is also a wrong pinout diagram.
@johnarnoldbrown
In know, but from the topic I tought I could add my comment here.