Measuring distance between two devices using puck.js

[espruino-discuss]

Posted at 2018-05-23 by Saurabh

Hi friends,

I am working on some project in which we have to measure the distance between two nearby device using puck.js . if distance is less then a meter . we need to emit LED.

One device is puck.js and other one is ESP32.
Help me to figure out this.

[espruino-discuss]

Posted at 2018-05-23 by @gfwilliams

Assuming the ESP32 is advertising, you should be able to use something like:

NRF.setScan(function(d) {
  if (d.addr=="...") LED.write(d.rssi>-70);
});

You'll need to change the address and probably the RSSI value as well, but that should be a good start :)

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Posted at 2018-05-29 by Saurabh

Thanks its working

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Posted at 2018-05-29 by @gfwilliams

Just a quick note that doing this does use a lot of power (as the radio is always receiving) so will run the battery down quite quickly - so you might want a way of only enabling it when you need it.

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Posted at 2024-08-17 by user158543

Hello, I am trying to do something similar but I have two puck.js how would this programming change? I am actually trying to get the signal and turn it into a distance, or just display the strength to eventually turn it into a distance?

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Posted at 2024-08-27 by @gfwilliams

The code should be exactly the same... You can just use setScan/requestDevice/etc and look at the rssi value in what's returned.

Or, if you've got an active connection between the two devices you can use setRSSIHandler (https://www.espruino.com/Reference#l_BluetoothRemoteGATTServer_setRSSIHandler) - with the active connection it is a lot more power efficient than constantly scanning for advertisments.