As the coronavirus pandemic continues, we’ve seen several social distancing, and contact tracing solution came in the market to stop the spread. Employers and businesses will want new devices to help keep social distancing when people return to work. In this case, Bluetooth technologies can be very useful.

When a Bluetooth device connects to another Bluetooth enabled device, it measures the signal strength as RSSI ( received signal strength indicator). The connection strength depends on the distance between the devices — The connection will be strong if two devices are nearby. As the device move apart, the connection weakens.

It is also possible to scan for nearby devices and read the RSSI value without establishing a connection, this makes it very suitable for looking after nearby devises as majority of people carries a smartphone with Bluetooth on.

BLE Measures Distance in 3 ways

Following are the three primary approaches to measure distance using BLE:

BLE RSSI (received signal strength indicator) Alone

This solution uses (Bluetooth Low Energy) BLE Received Signal Strength Indication (RSSI) to measure the distance between the receiver and the transmitter (scanner and advertising device) .

It is possible to increase accuracy by repeatedly scan the RSSI values and create an average over a fixed determined period.

BLE with Ultra-wideband (UWB)

Another likely option is the combination of BLE with Ultra-wideband (UWB). UWB is a low energy radiofrequency technology that can transmit short-range, high bandwidth messages over the radio spectrum. UWB is best suited for location tracking, data collection and short-range indoor application. Combining UWB with RSSI helps get highly accurate measurements, but it has a higher BOM (bill of materials) cost due to the UWB chip.

BLE Based Proprietary Distance Measurement Technologies

BLE-based proprietary technologies can add distance measurement capabilities which makes it more accurate. It can combine Bluetooth LE data packets with constant tone frequency exchanges in order to generate the strong signals needed for more precise ranging. This technology can also be more accurate than RSSI alone and BLE with Ultra-wideband.

Developers can use smartphones Bluetooth technology that is already installed in the devices to perform contact tracing, but this approach has some problems related to privacy. Therefore, a BLE device that does not require any information from users is the right solution. For instance, BleuIO can be used to measure the distance without having to worry about privacy and security. The BleuIO is Bluetooth low energy solution that can be used to create new BLE 5.0 applications in the fastest and easiest way. Just use the AT Commands available on the device. Details about the AT commands will be found on getting started guide which will help anyone make a fast peripheral or central application (or both), on an incredibly low power platform without having to develop a single line of embedded code.

We have created a sample project on Get Bluetooth Device Distance Using BleuIO.

The device can be bought from https://www.bleuio.com/, and it will only cost $15.99.