MCU restarts when waiting for a packet in RX state.

[MarcinB]

Hi,

I have a problem with nRF52832 after entering the radio RX state. I use a proprietary protocol with fixed packet length. Packet  transmission works fine, receiving the packet also works fine, when the packet is receivet within hundreds of microseconds after entering the RX state. But if the radio waits longer for a packet, the MCU restarts. The register RESETREAS contains zeros after restart, so the reason is unknown?? Does anyone have any ideas what may be the source of the problem?

Tahnks for any help in advance.

[Kenneth]

The register RESETREAS contains zeros after restart, so the reason is unknown??

What battery do you have? RESETREAS=0 should mean power on reset or brown out reset.

Kenneth

[MarcinB]

my circuit is powered from nRF52832-DK. Right after programming, the register RESETREAS has the flag SREQ set, others are cleared. After restart all flags are cleared.

Marcin

[Kenneth]

Hi,

Check if you have large dip on the VDD? Ref from datasheet:

"A step increase in supply voltage of 300 mV or more, with rise time of 300 ms or less, within the valid supply range, may result in a system reset."
From: https://docs.nordicsemi.com/bundle/ps_nrf52832/page/power.html 

Kenneth

[MarcinB]

Kenneth, you've led me right to the source of the problem. My circuit was powered from the development board, but I forgot that there was an ammeter connected to the circuit so that I could monitor the current draw. Apparently the ammeter's resistance was high enough to cause voltage drops on the CPU power supply, hence the restart.

Thanks a lot for your help!

Marcin