nrf52 Low temperature issue

[jayesh]

I am using nRF52832 with SDK 11.0.0 and S132_V2.0.0 for my application. My beacon is inside Refrigerator where temperature varies from -2 to 20 degree.My Beacon code is in Pheripheral mode.

I have found following issue with my hardware.

If I put hardware in Refrigerator then I found that at low temperature(< 0 degree) after some time advertisement goes off. If I took out hardware out of cooler then after some time it starts advertisement again. Please note I have enabled internal DC to DC converter in nRF52. One thing i have done that i have disable DC to DC converter and test again in cooler then advertisement doesn't go off and works ok. But that to is not 100% reliable.

Same thing when i try with third party nRf51 module all is working good. I am keeping both nRf51/52 Beacons inside refrigerator. After sometime nRf52 stops advertising but nRf51 is working good whole day at +-2 Degree celsius.

Now when i expose this nRf52 hardware at room temperature then its working good. Its advertising as well as connecting whole day.

So i am bit confuse why this thing is not working at 0 degree celsius, Since as per data sheet it should work upto -40 degree celsius.

Even all the components which i have used in this Beacon Hardware all can work upto -40 to 75 degree celsius.

A quick reply would be quite helpful..

[jayesh]

Hi Aryan,

I have read the content of FICR resistor keeping my Beacon in debug mode. I an attaching Screenshot of FICR structure Watch window.

I am using 32MHz crystal for our Custom BLE module and 32 KHz for MCU.

For enabling DC - DC converter i am enabling DCDCEN register. I am using below line in my Initialization code for Enabling it

NRF_POWER->DCDCEN = (POWER_DCDCEN_DCDCEN_Enabled << POWER_DCDCEN_DCDCEN_Pos);

For disabling DC DC i am just commenting DCDCEN register line since by default DC DC mode is disabled.

Even i have tested this thing with 3 to 4 nRf52 Beacon board but same thing happens.

[Susheel Nuguru]

Hi Jayesh,

I cannot access that link. It is possible that the different crystal capacitor value is the issue here, Then you need to change the board CL value to suit it.