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?

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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.
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Thank you. Thank you. Thank you.

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

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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.

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@isyisy
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?
TIA
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.

Hey! so from the images bellow, it looks like you guys are soldering the antenna to the ground. How does this help? Shouldn’t the antenna be soldered on the feed, and also disconnect the old antenna?

  • It looks like I cant include images or links in my post, but from the schematics, the lower pin next two each other on the antenna chip is ground and the upper is the signal.

Hi there,

So , First I doubt the Juice is worth the squeeze… Results are hit and miss, not really meant for it, I think soon there will be another option that can choice between Internal or EXT, like on the C6. I wouldn’t waste my time the circuit has to be carefully tuned as not to damage the Xiao.

Not all those antennas’ are created equal, DON’T use one for Lora, meant for WiFI or visa-versa.

HTH
GL :slight_smile: PJ :v:

BTW, Nordic makes a range booster chip for BLE, seeed may offer a sandwich board for it would be great. :+1:

not to disagree but i have had success with using the white antenna above (2.4ghz) for LoRa… also the black (910 mhz)… they both seem to work equally well on my moonshots… I understand this should not be so

2.5 km Neighborhood Meshtastic Moonshot?

El cheepo antenna is way better than built in IMO

I’m making a project just for fun! So tinkering around is welcome!
That would be a solar lora node mount in my rooftop, which would need the extra bluetooth range if I can squeeze some! Soldering in these tiny contacts sounds fun!
Are my assumptions correct though?
Ie - remove the old antenna, and just solder the signal to “FEED” and the shielding to GND?

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Hi there,

Sure, I agree… Nothing ventured nothing gained, I would say Yes…
remove and replace. :crossed_fingers:

HTH
GL :slight_smile: Pj :v:

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the only thing i might do is solder the connector down so it doesnt pop off… otherwise you are wasting your time IMO


Am i coming in too late… but you wouldnt want to remove the PDM microphone Chip… you would want to remove the Antenna Chip right? this image is something else right? which side of the antenna chip is ground? left or right?