Efficiency of the Async UART API

[blitz0145]

I would like to know how efficient it is in terms of power to use UART via the async UART API.

Does power consumption differ when its receiving data vs when it is idle?

Also, is there a power efficient way to detect connection and disconnection just by using the UART TX and RX pins? 

We could use LPUART but unfortunately we do not have extra pins left on our nrf52832.

[Kenneth]

Hello,

While UART is in receive mode it will use relatively high power consumption, it's only when you stop receive mode that the current significantly drop.

To be able to power optimize any application with UART, you need some external hand shaking signals (e.g. flow control) to turn the UART to receive mode only when there is data. I do not see any good way to avoid this, but I guess you can periodically (e.g. every 100ms) send some UART data to inform that you will now turn on the UART RX for a short period (e.g. 5ms) of time.

Kenneth

[blitz0145]

Makes sense; we'll try to free up two pins to get flow control going. If not we'll periodically send data- get some sort of a timing based control going.

Thanks for the help Kenneth! Closing this thread.