nrf52840 ncp bit rate

RE: nrf52840 ncp bit rate

Tiago Morais — Tue, 19 Mar 2019 11:12:57 GMT

Yeah! Once I created a topic about the spinel protocol, but I was able to solve that already :D

it took me a while, but I was able start a code using the spinel protocol to communicate the uController and the NCP. For a starter version, it works quite well

I wanted to decrease the bitrate because my team only had the nrf52840 dongle and wanted to try to increase its range. Instead we found another compatible device to work with ncp: BL654 that has a external antenna, and also I received the news, after doing some tests, that the distance we were able to communicate was over 1000 m using the ncp code and our mqttsn client.

Eventhough we were able to increase that range, I was still trying to decrease its bitrate just to test it :D, but since it's not possible to change the openthread's default bitrate, I'll keep that way for now

Thank you very much Edvin!

untill next time!

Best Regards,

Tiago

RE: nrf52840 ncp bit rate

Edvin — Tue, 19 Mar 2019 07:32:06 GMT

Ah. It didn't quite add up, but I saw we discussed spinel and UART in one of your earlier tickets, so I assumed it was the same.

But unfortunately, no. It is not possible to change the bitrate of IEEE (which is what OpenThread uses). It is by default set to 250kbps using 2.4GHz, and this is included all the headers. You will see that the payload bitrate is lower than this.

The only option if you want to change the bitrate between two devices is to run e.g. BLE concurrently. BLE or even ESB (Enhanced ShockBurst, Nordic Proprietary radio protocol, which would require Nordic chips in both ends). This will however not increase the throughput of the network, only between these two nodes.

Best regards,

Edvin

RE: nrf52840 ncp bit rate

Tiago Morais — Mon, 18 Mar 2019 13:57:37 GMT

Hello!

Thanks for your reply

I may have expressed myself badly ( first i talked about the uart, and then asked about the radio, without saying it... sorry)

what I do want to change is the radio bitrate. Is it possible to change it?

BR,

Tiago Morais

RE: nrf52840 ncp bit rate

Edvin — Mon, 18 Mar 2019 12:56:46 GMT

Hello,

So is it the UART bitrade that you want to change? Or the radio bitrate?

As you can see here, a handful of the peripherals such as the UART are set up and compiled in the openthread build that is included in the SDK. If you want to change the UART settings, you must rebuild the openthread library. As you can see from the link, the UART baudrate/bitrate is set in platform-config.h, on line 110. If you want the new openthread build to work with the current SDK, you should use the same build commit that was used with the SDK. The commit number is mentioned in SDK_for_Thread\external\openthread\project\readme.txt.

Best regards,

Edvin