Power consumption Problem in nrf51822

[Rahul Sahu]

hi, I am working with nrf51822 board using softdevice(s130).I am making ble initialization and continuously calling the power_manage() function in which sd_app_evt_wait() function is calling. I am getting 1mA current now but according to the document we will get less than 1mA.why it is so?

[Roger Clark]

Have you tried using the beacon example?

[Rahul Sahu]

Thanks Roger for the response.I tried but it's not work.

[Rahul Sahu]

hi Roger beacon example is working fine now. I am getting 400uA current. But I want to know how they optimize the power consumption in beacon.

[Roger Clark]

400uA seems far too high for the beacon, even assuming you are taking an average

I think the power should be something like 5uA all the time + 27uC per transmission (note this is uC not uA, so averged total current will depend on advertising period)

Try commenting out the line that starts the advertising.

I don't this this affects the power unless you want to keep time while in low power mode, but boards which have an external 32kHz crystal take less power to keep accurate time than if you just use the internal RC oscillator, as without the 32kHz crystal the MCU has to wake and calibrate its self from the 16mHz periodically if you use the RC 32kHz osc. But the calibration is stuff is configurable and for the beacon example, I think it isn't enabled as the code presume you have the external 32kHz osc

[Rahul Sahu]

Now I got 4uA current without changing anything in beacon example code. But if I try to change the flag (NRF_CLOCK_LFCLKSRC) to internal RC clock as CPU frequency after that the current consumption is 3mA. can you suggest me why?