PuckJS RSSI values issue

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  • Hi,

    I am trying to use PuckJS as BLE beacon(just advertise a mfg data at 750msec interval) for an indoor tracking POC. I am having another set of BLE modules as receivers that look for the RSSI from the PuckJS based on beacon advertising and transmit to a calculation server. What I observed is that the RSSI values of PuckJS change significantly though the PuckJS is stationary but there is slight change in orientation. @1meter distance, the RSSI values change from -74db to -84 to -89 or more with puckjs rotated from 0degree to 30degree and then 90degrees etc.

    Is there way we can avoid this fading behavior or boost the signal strength that can help on the output performance? Any code change or a hardware extension is suggested? If so, How do I do this?


  • Hi - is this with a Puck.js v1 or v2?

    On the v1 the NFC coil ran a little too close to the aerial and that affected the performance in some directions. On the v2 the situation should be better, but I'm afraid it's still going to be directional as there's a big metal battery in there which will shield the radio transmission in some directions, and even ignoring that the aerial itself doesn't have a very even transmission pattern (image attached).

    It's an unfortunate side-effect - the ceramic aerial gives you better signal strength vs a PCB one, but it's more peaky.

    I'm afraid there's not really a fix, apart from to position the Puck such that the angles you are at relative to it are where the signal strength doesn't change too much.

    Otherwise I do sell MDBT42Q modules with an antenna connector (https://shop.espruino.com/mdbt42q/mdbt42­q-breakout-ufl) and with the right antenna on them they'd be a lot less changeable based on direction

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    • Screenshot at 2020-12-03 16-35-16.png
  • hi @Gordon, thanks for the quick reply, appreciate it. We use V2, will look into options and explore on stable signals that can help our issues if any.

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PuckJS RSSI values issue

Posted by Avatar for user121987 @user121987