Ble_app_uart current consumption

[Punit]

I am developing a battery powered application using the Nordic UART Service.I intend to use the ble_uart peripheral example as it is , modifying it as per the application.The peripheral is battery powered and has to do both receive & transmit tasks intermittently.

My questions are:

1] Is the example application power optimized?Can i use it off the shelf? 2]If not, then how do i bring down the power to lowest values possible?

i wish to have the NRf51822 chip to wait to receive data as when it is available and i am not using flow control..

Any suggestions..

[bjorn-spockeli]

Hi Punit, are you only using the Nordic UART Service(NUS) to send data to and from a central? If your not using the UART peripheral(Hardware UART) then you can disable it to reduce the current consumption. If the UART peripheral is enabled it will keep the 16MHz clock on all the time which will add 500uA to the constant current draw.

[Punit]

Yes, i am using the Hardware UART...I plan to disable the TX by default & enable it when required...How much improvement can i expect with this...??I am awaiting new board and can only take a trial then...

[bjorn-spockeli]

Ok, do you plan on having the UART receiver turned on at all times? Or did you mean turning off the UART peripheral and then enabling it when you need to transmit data, if that is the case then you should see a reduction in the current consumption of 400uA (16MHz RC oscillator) + ~210uA ( UART run current) = 600uA whenever you turn off the UART peripheral.

[Punit]

Yes,..but RX will be enabled all the time....only TX will be disabled/enabled as per need..

[bjorn-spockeli]

The 16MHz RC oscillator will be running if the UART receiver is enabled, i.e. you will see an increase of ~400uA in the current consumption.