RE: Using UARTE in nRF52832

dpalma — Tue, 29 Mar 2022 14:12:33 GMT

Hello,

Thank you very much for your response.

I get that developing an SDK for an SoC/SoP must be really tough. Some people want high-level libraries and others prefer functions closer to the hardware level. However, I think that even simple firmware development is quite hard on the nRF SDK. Maybe the whole product is targeted to actual firmware developers (I am not).

Getting to the actual point. I have a MATLAB app for passing some parameters to the nRF through UART. Then, the nRF programs and controls some electronics on my board. Also, I want to transfer some real-time data back to MATLAB. Thus, I guess that I better implement UARTE. I will take a look at the example in SDK\examples\peripheral\libuarte.

RE: Using UARTE in nRF52832

Edvin — Tue, 29 Mar 2022 13:42:50 GMT

Hello,

I am sorry that your first impression of the SDK is not good.

[quote user=""] I found that nrf_libuarte_async is the proper library for handling UARTE communications, right?[/quote]

That is correct. The libuarte library, which is demonstrated in the example found in SDK\examples\peripheral\libuarte is designed to collect multiple bytes into a string that either fills up the buffer size, or times out.

Remember that there is no "message size" in UART. It is just a "simple" protocol sending byte by byte. One way to work around this, which is probably the most common way, is to have either a set message length, that you know that the other device will send, or to use some special byte to mark as the end of the string ('\n' is commonly used). If you have an option to do that, since you are sending the data yourself from Matlab, I would recommend to just keep receiving bytes, and look for the "stop" byte that you have decided on. This is more or less what the ble_app_uart (SDK\examples\ble_peripheral\ble_app_uart) example is doing. It will trigger on either the stop byte or when the buffer is full.

If that doesn't suit your use case, then you can use the libuarte. Just note that this driver demands some more resources to run (more timers).

Best regards,

Edvin