Small range with OpenThread.

RE: Small range with OpenThread.

Jørgen Holmefjord — Tue, 18 Jun 2019 14:12:48 GMT

Hi,

Did you see this blog post?

If you are inside and you have a noisy environment, or have many obstacles between the devices, the range will be drastically reduced.

Best regards,
Jørgen

RE: Small range with OpenThread.

Kostiantyn Makhno — Tue, 18 Jun 2019 12:05:23 GMT

So, last measurements I had a range approximately 30 meters with 0dBm. By 8dBm I had ~32 meters. Although, perfectly I should get the range by sqrt(Transmitter Power) times more than by 0dBm.

RE: Small range with OpenThread.

Kostiantyn Makhno — Tue, 18 Jun 2019 10:43:23 GMT

I mean, that when I use multicast transmission I get better range than I use unicast. But I think it doesn't matter.

RE: Small range with OpenThread.

awneil — Tue, 18 Jun 2019 10:14:48 GMT

[quote userid="80635" url="~/f/nordic-q-a/48708/small-range-with-openthread/193367"]most significant influence has the direction of the antenna[/quote]

PCB chip antennas are often quite directional

The antenna datasheet will show the radiation pattern - ie, how the gain varies in different directions.

It might be included in the Particle documentation - otherwise you will have to google the particular chip antenna used ...

[quote userid="80635" url="~/f/nordic-q-a/48708/small-range-with-openthread/193367"]it seems to me that is strange behaviour[/quote]

No - it is perfectly normal & to be expected.

[quote userid="80635" url="~/f/nordic-q-a/48708/small-range-with-openthread/193367"]So, Is there a difference multicast or unicast I use[/quote]

What do you mean by that?

RE: Small range with OpenThread.

Kostiantyn Makhno — Tue, 18 Jun 2019 10:07:01 GMT

Influence on the range.
<So, Is there a difference multicast or unicast I use?

RE: Small range with OpenThread.

Kostiantyn Makhno — Tue, 18 Jun 2019 10:04:24 GMT

It is particle xenon board with nrf52840 chip with PCB antenna. Yes, I changed power at both ends. So, what I observed that is most significant influence has the direction of the antenna, and so example on distance 0.1m I got RSSI -28dBm, then I moved one of the boards on 0.5m and got RSSI -50dBm, it seems to me that is strange behaviour. So, Is there a difference multicast or unicast I use?

RE: Small range with OpenThread.

awneil — Tue, 18 Jun 2019 09:30:26 GMT

You need to give more details of what, exactly you used and how exactly, you performed your tests.

In particular:

Was this with two nRF52840 boards ?
Did you increase the Tx power at both ends of the link?

[quote userid="80635" url="~/f/nordic-q-a/48708/small-range-with-openthread"]How I can change IEEE802.15.4 i.e. to LR-BLE or BLE-1Mbit, is it possible[/quote]

They are entirely different radio links - so you would have to redesign & re-implement your entire system.

Yes, the nRF52840 can do both IEEE 802.15.4 and BLE.