Aconno ACN52840 module does not resetting after programming by J-Link, RTT not working.

[Grzegorz K]

After problems with the programmer I have successfully flashed simple custom board with ACN52840 module, but the unit does not resetting after flashing using J-Link Pro. Starting after grounding reset pin or "nrfjprog --reset".

Terminal show:
Enabling pin reset.
Applying pin reset.

Simple board configuration:

3xVCC shorted

3xGND shorted

470uF capacitor across supply

Reset pulled-up by 10kohm.

Jlink pro connected to SWDIO, SWDCLK, GND, Vcc.

Another maybe related is that there is nothing on RTT viewer, on the nrf52840DK RTT and reset after programing is working as it should.

[Jared]

Hi,

Are you able to do a recover with nRF Command Line tools:

nrfjprog --recover

Is any error returned?

If an error is returned, can you repeat it but with the --log command added:

nrfjprog --recover --log

regards

Jared 

[Grzegorz K]

Hi, recovered successfully without errors but it did not change anything.

Recovering device. This operation might take 30s.
Erasing user code and UICR flash areas.