Any nrf51 sample that consumes less than 0,500 mA?

[Alex Co]

Hi I am trying to optimize my nrf51 app for low power. However I can just reach 0,500mA when just advertising (advertisement only is ok for me). Do you know or do you have any sample that consumes less than that?

Thanks a lot

[bjorn-spockeli]

Hi Alex, 

I am assuming that you mean below 500uA in average current consumption while the nrf51 is advertising and not the TX peak currents. If you compile the ble_app_beacon example for the nRF51 in SDK v12.3.0 you get a current consumption of about 180uA, see screenshot below

Best regards

Bjørn 

[Alex Co]

Hi

0,500mA => 0.500mA !

Which kind of measurement instrument are you using?

I am using a multimeter. I set select button to 20mA and put is in series between 3.3v and nrf51 vcc input and I see 0.500 on the display (0.500 when sleeping ( sd_app_evt_wait ) and 0.565 when sending)

I am using sdk 7 and SD110...

Which type of power saving are you using: System OFF Mode or Low Power Mode?

(By the way, I am using 29 bytes of the advertisement array)

Thanks

[bjorn-spockeli]

HI Alex, 

I am using the Nordic Power Profiler Kit(PPK) to measure the current consumption of a nRF51 DK, but it also supports measurement of external boards, e.g. custom boards. What kind of dynamic range does your multimeter have? It needs to be accurate from a couple of  uA up to tens of mA. In general we recommend using the PPK or a proper power analyzer.  

The beacon example only goes to the System On: Low Power mode. 

I strongly suggest that you move to the latest SDK that supports the NRF51, which is v12.3.0 and the S130 SoftDevice. 

Best regards
Bjørn 

[Alex Co]

I tried already to move to s130 and v12 but then the compiled app does not run anymore and I can not figure out why (no nice debug (st-link based))

Can number of bytes beeing advertised influence the current consumption too much?

[bjorn-spockeli]

Did you make sure to point to the correct softDevice headers and take into account the increased size of the S130 over the S110? You should be able to debug the application and see if you enter main at all or if its some of the softdevice initialization functions that are asserting. Are you using Keil or GCC?

The ble_app_beacon example in SDK v12.3.0 use almost the entire advertisment packet, i.e. close to 30bytes with an advertisement interval of 100ms. So unless you're using a much lower connection interval then this should be comparable to what you're seeing. 

Best regards

Bjørn 

[Alex Co]

Usually when I am trying a new sdk I simple open ble beacon example, compile it and burn using stlink

I am using GCC

My app is advertising in periods of 10 seconds...