Flashing pca10059

[Michal]

Hi, I have pca10059 dongle. I soldered goldpins to swdio and swdclk lines to be able to flash it using external nrf dk. So I connected external jlink programmer and was able to reset board. So I decided to erase it to flash my software. But right after erase command I was not able to do anything with dongle and I was just getting JLink errors. What is the solution are possbile problem?

Regards,

Michał

[Vidar Berg]

Hi Michał,

The problem is that UICR.REGOUT0 register got cleared once you did the chip erase.  Thus changing the I/O voltage from 3.3V to 1.8V . Unfortunately, the only way to re-program the chip is to use an external J-link programmer that supports 1.8V programming. The Jlink lite on the dev kit requires a target voltage of >3v. Do you have an external programmer you can use?

Our documentation should definitely include a warning about this. I will report it internally. 

[Michal]

Hi. No, I dont have access to external programmer, I only have nrf DKs. So what should I do ?

Why this does not happen on pca10056 or pca10040?

[Vidar Berg]

Hi,

The dongle operates in high voltage mode while the pca10056 is configured for normal voltage mode by default. If you have a pca10056 you can try to power it through nRF_USB instead as that should change the DKs VDD voltage to 1.8 V (measure to make sure).

nRF52840-DK Debug out

[uhrheber]

I ran into the same problem. Is it safe to power the dongle externally, when I close SB1? (without USB connection, of course)

[Vidar Berg]

Yes, as long as you remember not to plug it into a USB port. Sorry that you ran into this problem. We will include a warning about this next time we update the documentation. 

[uhrheber]

I could reflash the dongle, but the main voltage regulator is still at 1.8V. What's the easiest way to set it back to 3.3V