NRF24L01+ STOP STATE

[sustek.vladimir]

Dear Nordic Semi, 

I play with NRF24L01+ shield and, what I control using STM32F411RE or ADuCM4050. 

Once a while, NRF24L01+ chip stops and on the MISO line with permanent 0xFF value.

To be precise, each SPI transaction NRF24L01+ should return content of STATUS register.
However, maximal returned value of STATUS register can be 0x7F (7th bit is reserved).


Is there any other option than power cycle, to leave this "stopped" state please ?

Chip enters this state especially after reset of MCU, when undefined logic value can be on 
the SPI lines (note that maximal voltage cannot be higher than 3.3V = VCC of system).


Thank you,
Regards,

Vladimir

[Kenneth]

Hello,

You should use a 100ms delay after power ON before you read and write to the nRF24L01. You may also try to pull CE low and write 0 the PWR_UP bit in the config register. Other than that I don't have any good suggestion, since I have not heard of this situation before. I guess it's always a possibility to control VDD through a transistor to power cycle the nRF24L01 from the MCU to recover also.

Best regards,
Kenneth