BLE central low power

[herve bourricaud]

Hi,

I'd like to put a BLE central in low power between two scan. actually I use the example Ble_app_uart on a dk board PCA10028 and a second dk board as advertiser with ble_uart and the 2 bords can communicates !

measuring current with a multimeter:

on the advertiser: OFF mode -> 0.6uA advertising: 13mA

on the central:

• current in low power is 1.3mA
• current in scan mode is 7.5mA

in the main loop there is a call to sd_app_evt_wait witch supposed put the micro in low power mode

but , is there a way to do better than 1.3mA ?

my idea will be to put central OFF for long time (30s) and to be wake up by a timer and start scan for 1-2s

any help welcome !

[Kenneth]

Hi, it might be that the central is in debug mode, have you tried to power cycle the the central? Can it be that you have any peripheral enabled (e.g. UART) that is causing the 1.3mA between scan windows? Typically the idle current in system ON with RTC is about 4uA between BLE events.

[herve bourricaud]

thanks !

you find the 2 problems

• debug mode 1.4ma --> 1mA after power cycle
• uart stil lactivated --> small change to init/disable when connect/disconnect event

now average current scanning is 4.3uA !