Device fails to advertise and has become non-responsive

[kumar narendra singh]

Hi,

I am using NRF52832 SOC for my application. I have developed application for beacon advertisement based on the nrf sdk. I am facing some issue in device advertisement and even gpio toggling. I have used seeger j-link flash lite application for flashing the binaries. I erase the flash,load the softdevice and then load the application hex file. programming says successfully done but my device is not advertising. I had selected 4000KHz as speed by mistake. i am facing issues in 4 of my devices for which i used 4000Khz clock. Even simple application for gpio toggling doesn't work and SOC chip seems to be non-responsive. The very first time i had flashed, all 4 devices were working fine i.e gpio was toggling, beacon advertisement was working but later it stopped working. Programming succeeds everytime i flash but my application doesn't run at all.

My question is can 4000khz speed setting cause this damage? If yes then is it permanent damage? If no then is there any way to recover from this condition. I repeat, i don't have problem in flashing application on these 4 boards and everytime flashing passes without any problem

[Kenneth]

Hi,

You can use any speed, there will be no damage. Some things to check:

- If you have enabled debugging (e.g. uart), make sure the RXD line is pulled high externally if no serial port is attached.

- Make sure you have the correct lfclk setting, for instance if your board does not have external 32kHz crystal, then you must use internal lfclk.

- Check if you may have (for instance by accident) enabled pin reset (CONFIG_GPIO_AS_PINRESET) or nfc pins (CONFIG_NFCT_PINS_AS_GPIOS) in your code (see system_nrf52.c), because then you will need to handle these pins correctly. For instance you may need to pull the reset pin high (to vdd) externally.

- Try 'nrfjprog --eraseall' to make sure UICR is erased before programming.

- Make sure you are programming correctly softdevice for the chip and sdk version.

Best regards,
Kenneth

[kumar narendra singh]

Hi Kenneth,

Thanks for your reply. i will check your recommendations. I have some updates about my device.

Initially 4 of the boards got problem and evenif i do erase all and loaded softdevice and application, device was not able to advertise as beacon or gpio toggling. Later i used nrfgostudio and loaded bootloader,softdevice and then application and all 3 non working boards started working i.e led started toggling and beacon works. But after i power reset, it stops working. This i have tested multiple times and everytime i program it works but not after reset. One of the board does work after power reset also. so 2 out of 3 boards have problem after reset i.e. led doesn't toggle and beacon doesn't work.

For test, i have tested led blinky application on all 3 boards and it blinks without problem even after reset.

Can you please tell me what could be reason for this behavior? The same piece of code works fine on development kit. I have attached schematic for your reference. 32.khz crystal and capacitors are placed on board.