Bluetooth 4.0 adapter with external antenna

Question

I'm looking for a bluetooth 4.0 (BLE) adapter for raspberry pi with an external antenna acting as a bluetooth signal booster.

My raspberry pi is inside locked booths of parking lot which senses the cars passing by. These guest cars are provided with bluetooth odb adapters. But the problem now is if the booth is closed (as it is unmanned), the bluetooth signal strength is not that great. I'm not interested in rssi adjustment solutions for proximity decisions. I've tried those.

I want to know if there are off the shelf bluetooth adapters with the external antenna.

Answer 1

Have a look at the Ubertooth One from Great Scott Gadgets; it accepts 2.4GHz antennas with RP-SMA connector - the type usually found on SoHo routers...

https://greatscottgadgets.com/ubertoothone/

https://github.com/greatscottgadgets/ubertooth/wiki/Ubertooth-One

At a glance, current consumption ranges from 90 to 220mA, so if not using a Pi 3 you may need a USB power injector, like this one:

https://www.eeweb.com/extreme-circuits/usb-power-injector-for-external-hard-drives

Answer 2

I've extensively used the Ubertooth One. It's a packet sniffer meant for debugging and hacking and requires a fair bit of Linux knowledge and time to set up.

As an alternative, I found this. It claims 300m range with +19dBm transmit power. That should suffice when the booth doors are shut.

It's advertised as 4.0 + EDR, which I've never seen before. This might be a Bluetooth Smart Ready device meaning that it supports Bluetooth Classic along with LE, but most people advertise a device as Bluetooth Smart, Smart Ready, or Classic.

Just make sure this isn't a $63 piece of junk.

I hope this helps.