Anchor to Bridge distance reading


I am trying to solve a similar system to this post: Using an Anchor as bridge - #3 by elontech_jonas

I want to have one tag and one anchor/bridge.

I want to measure distance between the tag and the bridge/anchor. I want to connect to the bridge with a pi and talk UART to receive the user data sent from the tag to the bridge/anchor.

The user data will be sent by the tag and will include the distance from tag to anchor/bridge. The anchor/bridge will receive the distance in the user data (iot data) and then forward it via the uart user data API to the raspberry pi.

The end goal is that the pi can tell how far away the tag is from itself. I do not care about position, I only need distance between the two units.

Is this a valid approach? From what I can gather it seems like I would need a tag, anchor and bridge device. However it seems like this should be able to be done with only two nodes, a tag and a anchor/bridge.

Please advise, thanks.

Hi @mcelhennyi
the easiest way (but not power efficient) is to set TN as a static node (connected to RPi) and move with Anchor Initiator. In this configuration the TN can give you directly the distance.

The hardest way (but power efficient) is to move with TN an then you need anchor initiator and the bridge. There is no way how you can combine Anchor with the bridge into one device.


So if I go the first approach, can I sleep the anchor while it’s not moving? Then wake it up when it does move? Or would that only work for a tag node?

Why do you suggest it’s less power efficient to do it the first way?

Hi @mcelhennyi
the Anchor does not the power saving feature - it will remain powered on all the time. You can also power on/off the AN by external MCU - but it brings more complexity.

At the beginning I would start with the suggested scenario (TN static, AN moving) to test the system.

Regarding the final solution it is up to you and it depend on your use case.