Flow control options for nRF52833

RE: Flow control options for nRF52833

Marshall — Wed, 11 Jan 2023 09:53:31 GMT

Hi Benjamin

I'm trying to develop a Zephyr Driver for the SC16IS752 which is functionally similar to the one you have used.

Would you be able to share your library for the device, along with overlays, yaml etc to help get me started,

It would be really appreciated.

Kind Regards

Marshall

RE: Flow control options for nRF52833

bfrottier — Thu, 13 Oct 2022 15:11:17 GMT

Perfect.

Thank you Einar!

RE: Flow control options for nRF52833

Einar Thorsrud — Thu, 13 Oct 2022 11:26:04 GMT

Yes, the part about enabling flow control in the overlay file applies to other samples as well. (You can see it used a lot in the SDK if you search for "hw-flow-control" in all "*.overlay" files.)

RE: Flow control options for nRF52833

bfrottier — Wed, 12 Oct 2022 12:38:25 GMT

Hi Einar,

[quote userid="7377" url="~/f/nordic-q-a/92684/flow-control-options-for-nrf52833/390011"]

You are right that HW flow control is what is supported, not software flow control.

You are right about the Kconfig configurations when using Zigbee. Note that CONFIG_ZIGBEE_UART_SUPPORTS_FLOW_CONTROL is just a configuration for the NCP sample, and and if you look at the implementation of the sample (nrf/samples/zigbee/ncp/src/main.c) you can see how it is used. Essentially it reads the pins from the device tree overlay file, and configures the UART accordingly by calls to uart_line_ctrl_set(). The pins come from the device tree (or rather board specific overlay files in the sample), from the UART that is referenced by "zigbee_uart", which for the nRF52833 DK for instance, maps to uart1.

[/quote]

thanks for the confirmation and clarification!

[quote userid="7377" url="~/f/nordic-q-a/92684/flow-control-options-for-nrf52833/390011"]As the above configuration is only for the Zigbee sample, you can ignore it when it comes to what is used in the bootloader. That will typically use what is in the DeviceTree directly, so you would just need to ensure that you have control set for the UART instance,[/quote]

Does this also apply for other samples?

For instance radio_test (nrf/samples/peripherical/radio_test) would only requires to add in the device tree (or overlay) rts-pin, cts-pin and hw-flow-control?

Thanks!

Benjamin

RE: Flow control options for nRF52833

Einar Thorsrud — Mon, 10 Oct 2022 12:06:47 GMT

Hi Benjamin,

You are right that HW flow control is what is supported, not software flow control.

As the above configuration is only for the Zigbee sample, you can ignore it when it comes to what is used in the bootloader. That will typically use what is in the DeviceTree directly, so you would just need to ensure that you have control set for the UART instance, by having something like this in an overlay file for instance:

&uart1 {
	status = "okay";
	hw-flow-control;
};

Einar