Hello Nordic Semi,
After being in production of a battery powered remote control for over a year now, we have found many batteries going flat in the field. I have been able to observe that sleep currents for the nRF24L01+ are normally fine (approx 1uA), but occasionally increase to 20-400uA depending on the unit. It seems that most units do not display this issue, only some (which is curious).
On initial power up a given unit may be fine, but once the button has been pressed a few times to transmit our short message it may enter the high sleep current. Pressing the button to transmit again fixes the sleep current.
I have observed on other posts that this sometimes caused by floating I/O pin connections to the micro-controller. Here are my I/O port settings for RF chip interface during sleep mode:
IRQ Input(high impedance) MISO Input (high impedance) MOSI Output asserted low SCK Output asserted low CE Output asserted low CSN Output asserted high
This would seem to match the nRD24L01+ datasheet specification? If I change these settings, the problem gets worse with many units drawing high sleep current all the time. Also, setting all interface pins to output asserted low does not solve the issue either.
Can you please advise exactly the correct microcontroller interface pin settings to ensure low sleep current 100% of the time?
Regards, Peter
