Asynchronously receive over UART

RE: Asynchronously receive over UART

Aadishri GS — Fri, 24 May 2019 07:39:10 GMT

Thanks for the much needed clarification.

[quote userid="14926" url="~/f/nordic-q-a/47630/asynchronously-receive-over-uart/188885"]you will have to call it again when you receive the event/interrupt that the operation completed[/quote]

...means, before I exit from the event handler, I understand I must call nrfx_uart_rx

I did try the CLI example but my application has a screen which gets updated with live data apart from menu options. I also looked into BLE over UART, UART and Serial examples as well. Am using the examples to only get ideas as my requirement is just tx/rx one character at a time

RE: Asynchronously receive over UART

Jørgen Holmefjord — Thu, 23 May 2019 14:55:19 GMT

If you provide a event_handler to nrfx_uart_init, nrfx_uart_rx will setup the driver for "background" receiving of data. Note that this function only setup a single receive operation, you will have to call it again when you receive the event/interrupt that the operation completed. It will not run in an infinite loop that will receive anything that is transmitted to the device. Did you try out the CLI example? It sounds similar to your application.

RE: Asynchronously receive over UART

Aadishri GS — Thu, 23 May 2019 07:48:10 GMT

Once I call the nrfx_uart_rx function, the Rx will happen continuously over the back-end(like a separate thread running continuously in an infinite loop) when interrupt arrives each time. It is non-blocking as I am providing event_handler(which acts like an ISR) in nrfx_uart_init.

Am I right?

I had confusions with the examples as everytime the 'read' or 'get' functions are called in the examples explicitly.

RE: Asynchronously receive over UART

awneil — Wed, 22 May 2019 14:18:23 GMT

There is already a CLI in the SDK.

The Nordic UART Example (among others?) illustrates asynchronous (event-based) receiving from the UART peripheral.