Problem programming xuntong external board (no device detected)

RE: Problem programming xuntong external board (no device detected)

Chris — Tue, 17 Nov 2015 22:38:03 GMT

One thing with the Xuntong boards is they only have one oscillator on there. You need to change the reference code to support the derived oscillator..

It's been a while since I used them but I had the same problem. Something to do with the LFCLK (from rough rough memory) but that'll likely be your problem.

RE: Problem programming xuntong external board (no device detected)

Petter Myhre — Fri, 06 Nov 2015 11:57:31 GMT

There is a PAN on first revision nRF51822, "Missing pull down on SWDCLK". The workaround is to add an external 12 kohm pull down resistor on SWDCLK pin.

RE: Problem programming xuntong external board (no device detected)

Fabri_Cortone — Fri, 06 Nov 2015 11:23:47 GMT

3 V is the voltage...now i'm trying to program it with another segger (J-link lite) but nothing...the segger is discovered but the chip no. Another question: the xuntong chip is a first revision of NRF51822 so it's necessary the pull-up resistor on SWDIO pin??

RE: Problem programming xuntong external board (no device detected)

Petter Myhre — Fri, 06 Nov 2015 11:12:53 GMT

What voltage? It should be around 3 V for the interface MCU to detect it.

RE: Problem programming xuntong external board (no device detected)

Fabri_Cortone — Fri, 06 Nov 2015 07:56:03 GMT

Yes, I have powered it.

RE: Problem programming xuntong external board (no device detected)

Petter Myhre — Thu, 05 Nov 2015 14:40:25 GMT

Have you powered the external board?