GPIO output levels won't go to 3.3V

[jala]

Hi all,

I'm working on the nrf5340 with a modified mesh light sample and nrf connect sdk 1.7.1

I'm measuring from P0.28 which is also LED1 to the GND.

After programming the zephyr.hex with Programmer v2.2.0, I run .\nrfjprog.exe --family nrf53 --memwr 0x00FF8010 --val 5.

I can read the 5 at that address with nrfjprog --family nrf53 --memrd 0x00FF8010.

Still get 3V.

Thanks

[Turbo J]

Try setting the pin to high drive mode (H0H1).

If the LED was still connected to the pin, it will "load" the pin down a bit due to the current flowing into the LED. Normal pin mode has a lower current limit, thus you see a voltage drop across the output.