RE: Trying to shut down UART on 52840 running Zephyr

Simon — Tue, 11 Aug 2020 08:47:43 GMT

I don't think so. I don't have a complete overview of this, but I think the UART driver is by default not low power and expects that RX is always enabled on both sides.

The low power UART PR should fix this.

The commands for disabling UART are (e.g. for instance 0):

NRF_UARTE0->EVENTS_RXTO = 0;
NRF_UARTE0->TASKS_STOPRX = 1;
while(NRF_UARTE0->EVENTS_RXTO == 0){}
NRF_UARTE0->EVENTS_RXTO = 0;
NRF_UARTE0->ENABLE = 0;

In addition, you have to set CONFIG_SERIAL=n (disable UART) in MCUboot and SPM, and set CONFIG_CONSOLE=n (unhook UART printk calls from UART) in the applications prj.conf. But I don't think this will have any effect if the instance is enabled in prj.conf (e.g. CONFIG_UART_0_NRF_UARTE=y). Could you try to test this out and see if it works or not?

Best regards,

Simon

RE: Trying to shut down UART on 52840 running Zephyr

dboling — Mon, 10 Aug 2020 15:03:41 GMT

Thanks. I'll check it out. Is there no standard way to simply shut down the current UART hw?

Doug

RE: Trying to shut down UART on 52840 running Zephyr

Simon — Mon, 10 Aug 2020 12:09:21 GMT

Check out this pull request: https://github.com/nrfconnect/sdk-nrf/pull/2591

Best regards,

Simon