nRF51822 J-link Suppy Voltage too low. But firmware is running and connectable BLE

[Shey]

Hi,

I am having trouble in downloading firmware to my development kit. Previously, everything worked and the module already flashed with my BLE firmware. Today, as usual I power up the device and everything works well (detectable and connectable with my smartphone) but when I trying to download the firmware, the error prompted. It senses 0.0V instead of the normal voltage.

Normally this is caused by the power supply to the development board but my case seems to be different. I measure VTG pin on the board, it gives me 0V. I have tried to use another module (development kit came with 2 modules) the problem is the same. I also checked the downloader cable connectivity which is fine too. I wonder what reason causes this issue. J-link problem?

Hopefully someone can guide me out of this. Thank you very much in advanced

[FormerMember]

Hello,

As far as I understand the development kit board is not powered, and this board is mounted on a motherboard. Could you please verify if the mother board is powered "correctly"; measure the voltage between P7 (with jumper) on the mother board and GND on P5 (development kit board). When the motherboard is powered you should measure approximately 3.3 V.

If that is okay, you can measure the voltage on the development kit board; Pin 1 on K1 and GND on P5.

Regards, Kristin

[Shey]

Hi Kristin,

Thank you for your reply. I'm sorry, I think I should clarify that I do not have the motherboard. I power the development kit manually by my own board.

I did the measurement on my development kit between Pin 1 on K1 and GND on P5. I got 3V. At the same time the radio is on, I can connect my phone with it. However, the error persists.

[FormerMember]

Okay, I see. Which error message do get when you try to program the chip?