XIAO nRF52840 bluetooth antenna

I understand that the XIAO nRF52840 has a bluetooth antenna, but I am still looking for ways to improve its range. either ArduinoBLE (library tweaks) or hardware based.

can someone stir me to the right direction, please and thank you…

Also, is 5.5V its max voltage in?

1 Like

Hi, I don’t think there are additional places for additional bluetooth antenna for wider range, nor the software way. Sorry.
Also, the 5V and 3.3V will be the best input voltage. Otherwise the board might be damaged.
Hope this can help you!

You can improve the range by 10db by adding a small wire to the antenna post.

Make sure you only solder to one side of the unpopulated PDM pins. Or you can solder (carefully) directly to one of the two pins next two each other on the antenna chip.

Thank you. Thank you. Thank you.

It greatly improved and that its RSSI now is pretty much okay.

1 Like

Glad your setup worked! Even a small bare wire properly sized would yield good results. I got -75 vs -83 10 meters away.

How long should this bare wire antenna be? It‘s 2g4 right, so Lambda/4?

And can I also do this on the Xiao Sense, after desoldering the microphone (?) at these pins?

Had to do it like this because the PDM has a mic on the Sense-version. Works great so far, despite that I have bridged two pins on the antenna-chip by accident, doesn’t seem to make a difference. I used 0.5mm enameled copper wire ca. 30mm long.

1 Like

Did you solder it to the PDM pins or directly to the antenna feed?

If it’s on the PDM pins it’s rather a reflector than an antenna, correct?

Please explain much better what you do ? Please include a sketch with what you connect exactly!

If you solder the 3 pins from the MIC (PDM pins 4, 5, 6) to a wire, then these 3 pins are ground. So you only attach a wire to GND.

How shall this improve the Antenna ???

I did this as well. This thread saved my life.

I soldered a 5" piece of solid core wire to the left side of the existing antenna chip. The two pads on that side seemed larger to me. I did this on both of the Sense’s I’m working with and the range improved dramatically. They can even talk through the floor of a house.

Hi there,
Can you post a picture please?
GL :slight_smile: PJ

I don’t have the units anymore, but essentially, just solder a piece of wire to the right side of the blue BT chip. Right side assumes the USB connector is at the 12 o’clock position. When I soldered it to the left side as I mentioned above, the solder contacted the diode next to it. But the right side of the BT antenna chip has nothing close to it.