RE: Low Power UART migration

Kenneth — Thu, 24 May 2018 13:21:29 GMT

Hi,

So the problem here is in essence that the current consumption is high after calling:

NRF_UART0->TASKS_STARTRX = 1;

And the current consumption will go low only when calling:

NRF_UART0->TASKS_STOPRX = 1;

This means that you need some way for the application running on the nRF51822 to know/detect when to START and STOP the UART RX. The UART TX is no problem to use at any time, as it will only draw current while active transmitting data over UART.

My suggestion here is for the peer device to set a pin high or low when there is data to transmit to the nRF51822, then the application running on the nRF51822 can START and STOP the UART RX by calling above tasks to control the power consumption. It may for instance be possible by peer device using hardware flow control, then the nRF51822 can use the RTS pin as a normal GPIO input pin to know when to START and STOP the UART RX. In such case the application will use a software implementation of the flow control (for instance set CTS when there is TX data to send, and use RTS as input to start and stop RX data), instead of the hardware flow control.

Best regards,
Kenneth