Low Voltage (1.8V) on nRF52840 cannot program chip

[TasosR]

I have the USB Dongle (PCA10059) which after a full erase, has been giving only 1.8Volts to the GPIOs and the VDD OUT pin.

I am using the Segger j-link EDU progammer/debugger and I have connected it as:

VTref - VDD OUT

GND-GND

SWDIO-SWDIO

SWCLK-SWCLK

also I have connected the Dongle to the computer's USB port at the same time

I have searched the forum and the internet, the 2 possible solutions are:

Solution 1:

The command

(gdb) set *0x10001304 = 5

from here which doesn't see to work, I get the error:

Cannot access memory at address 0x10001304

Solution 2:

The command:

nrfjprog --memwr 0x10001304 --val 0xFFFFFFFD

which results:

nrfjprog --memwr 0x10001304 --val 0xFFFFFFFD

while dmesg command records the following:

[ 1972.462260] nrfjprog[3893]: segfault at fffffffffffffff9 ip 00007fede43f604f sp 00007ffd9c3bc450 error 5 in libjlinkarm_unknown_nrfjprogdll.so.9.8.1[7fede43ed000+15000]

The 2nd solution in a windows 10 machine  doesn't return any errors but never changes the Voltage to the desired 3-3.3V

[haakonsh]

The default value of REG0 output is 1.8V. When you erased the REGOUT0 register in UICR you accidentally removed your ability to program the device with your J-link EDU or OB.

There are two ways you can re-flash your dongle with a proper value for REGOUT0:

1) Get your hands on a J-link Pro.

2) Disconnect the dongle from the USB port and supply 3V externally to the VDD circuit of the dongle, then you should be able to program with the J-Link EDU or OB. 

[TasosR]

By VDD circuit we mean the pin "VDD OUT" which is connected to the processor,right ? wont it burn the processor? I will try it instantly to see what will happen ....

[TasosR]

same error again, device reports as 3 Volts

$ JLinkExe 
SEGGER J-Link Commander V6.42f (Compiled Feb 26 2019 17:01:38)
DLL version V6.42f, compiled Feb 26 2019 17:01:29

Connecting to J-Link via USB...O.K.
Firmware: J-Link V10 compiled Feb 21 2019 12:48:07
Hardware version: V10.10
S/N: 2601*****
License(s): FlashBP, GDB
OEM: SEGGER-EDU
VTref=3.006V


Type "connect" to establish a target connection, '?' for help

but nrfjprog gives the same error

$ nrfjprog -f NRF52 --program /peripheral/blinky/hex/blinky_pca10059_mbr.hex
ERROR: Cannot connect to any nRF device. Please make sure a device is
ERROR: connected to the debugger and supplied.

also, the segmentation fault remains

$ nrfjprog --memwr 0x10001304 --val 0xFFFFFFFD
Segmentation fault (core dumped)

[TasosR]

is there any way to check that the Dongle OR the chip are malfunctioning/burned/destroyed ?

[haakonsh]

Yeah VVD_OUT. REG0 might not like it, but I think it should be safe enough.