nRF51422 - no device detected

[Klemen]

Hi. I have a problem with programming brand new chips nRF51422. I have connected: Vcc (1, 12, 35, 36), Gnd (33,34,13), Swdio (23) Swdclk (24). christal on the board:   pin 45.46 -> 32.768kHz   pin 37.38 -> 16MHz

I program with nRF51-DK board -> external connector.

If i use some old chip, every thing works .. if i use brand new chip i get an error: No device detected, or readback protection May be set .. Recover button does nothing .. It says Erase completed, but nothing changed ..

I'm struggling with this for a very long time now .. Any suggestions?

Klemen

[Hung Bui]

Hi Klemen,

Could you update your schematic and layout ? Have you made sure you connect VCC to VTref on the Jlink connector on the nRF51-DK ?

How do you switch between old and new chip ? they were on the same board or you have different boards ?

Which software did you use for flashing ? Have you tried nrfjprog.exe ?

[Klemen]

Hi.

i use p20:

• DK --> my board
• 1 + 3 --> Vcc on my board
• 4,5 -> DIO/CLK
• 8 + GND (on the DK) --> gnd on my board

for programming i use nrfstudio.

If i solder on my board chip from some chinese beacon it works fine -> i can program the chip, but if i solder a brand new chip on my board -> no device detected?

Thanks, Klemen

This is what i get in nrfStudio

Blockquote

[Wojtek]

How does it say "erase completed" if you cannot click erase when no device is detected?

[Hung Bui]

I don't know what could be wrong here.

Could you read the laser marking on top of the new chip ? Have you measure the VDD on the board ? The onboard programmer only support 3.3V.

Have you tried with several chip or just one ?

[Klemen]

Hi.

New chip: N51422 QFACA1 1515AK Old chip (chinese): N51822 QFAAG3 1524FY

code "AC" does not exist in the datasheet? I tried with 2 new chips.. is maybe something wrong with this production line?