Bricked nRF51822

[GT]

Hello, I am asking for your help again.

I just managed to brick the chip that I am working with. The problem is that I am not able to erase or program the flash. However, other than that the firmware is running fine and I am able to event connect a central to the board.

The problem has something to do with the "pstorage" module and "sd_app_evt_wait" since I was working on module storing data in the flash.

I've tried this solution but it did't help.

Is there any other way to erase the flash?

Edit: Here is the sequence of commands that I have tried in the JLink console:

si 1 r h 
w4 4001e504 2 
w4 4001e50C 1 
w4 4001e514 1 r

[GT]

Solved!

The problems was low battery voltage. The datasheet of the chip says that the minimum operation voltage is 1.8 volts, however with target voltage of 2.17 volts, the J-Link can not establish a connection with the board.

Any comments on that?

[Stian Røed Hafskjold]

It depends on the J-Link you have. J-Link Lite does not support a target voltage of less than 3V (I think)

[GT]

I am using J-Link LITE. I just checked the specs and there is written that the "Target Interface Voltage" is 3.3 volts. In general a BLE peripheral is battery powered witch implies a target voltage lower than 3 volts. How these two facts fit together?

[Stian Røed Hafskjold]

Seems like the JLink Lite specs are a bit limited (maybe it just shows the typical value or something), and I couldn't find a proper datasheet for it either. But I did some testing now, and I am able to flash the chip all the way down to 2.3V using the JLink Lite. I also tested using a JLink Base, and I could flash the chip down to 1.8V.