Receiving Tag position using a bridge

we would like to use DecaWave in a bigger environment where around about 20 to 30 anchors will be needed.
What I still not understand after reading some Documents and playing around with a Development Kit is how the Gateway gets to know the Tag’s position.
As I understand the Documentation, the position is calculated on the Tag itself. How is this position send back to the network and more important: How can I read out that position not using the Raspberry Pi Gateway?

In our use case I don’t like to use the Raspberry Pi Gateway since the System must be able to run stable for a longer time and I don’t trust a Raspberry Pi and its SD-Card (at least if the SD-Card is not read-only). So I tried to use a Tag and a Bridge (both MDEK1001) and send the Tag’s position manually using C code API (onboard user application) as IOT data and receive it on the Bridge by manipulating the “dwm-range-iot” example. So far I failed getting it working.
I also tried sending IoT data from a Tag to a Bridge using Uart Shell (I configured one node to be a bridge using Uart Shell l command “nmb”). But that also fails. What I am worried about is that the Bridge seems to not be known to the Tag, when running “lb” shell command on the Tag it does not show the bridge (Running “lb” command on anchers lists the bridge correctly).
Any ideas? Do I need some special configuration when using a Bridge?

Hi Macio,

You could calculate positions on a server/computer instead, after sending all distances to it from an anchor, over LAN (or USB). And then send it to the network of whichever protocol & format you need. But to have this anchor (the “bridge” or “listener” then) know all the distances etc. you might have to implement your own firmware all together. In any case, when scaling to a bigger setup the MDEK kit might not be sufficient for all your needs.

Kind regards!

Hi Macio,

The tag is calculating its position and sending it over UWB to surrounding nodes within a the first message of the next TWR exhange. (Poll message).

Anchors and gateway are listening to this message (but note the position cannot be retrieved from active anchors). If you don’t want to use gateway, you can use a passive tag or anchors (but it has to be passive - its also called “listener”). The passive device will report position of surrounding tags over the UART interface when using “les” commands in shell mode.

I Hope it helps,

Thank you! That helps a lot.

I still wonder why I can’t see the IoT on that passive device (I used “udi” set to “show on” command on listener, and “uui ABC” on tag).

Hi Macio,

A listener will only receive location data, it does not receive IoT data.