Bluetooth Low Energy Proximity sensing less than 2 feet

arduinobluetooth low energydetectionproximity-sensorrange-detector

I am working on a project where I need a TX and RX to be able to sense if the modules are within 2 feet of one another. Ideally, we would like to only utilize BTLE 4.0 for both devices since power consumption is critical in the design. This is why BTLE was the ideal choice. However, it appears that within ranges less than 10 feet, BTLE becomes very inaccurate regarding proximity using path loss. We have been able to get it to detect within the short ranges we are looking for, however, to compensate for the inaccuracy we have to use averaging which makes it accurate but creates big delay times. We were looking at using IR but because IR is line of sight, this can be problematic for our use case. If anyone has any recommendations on how to perform proximity based services using BTLE within a 2 foot range with fast response times, i.e. within 1 second, it would be greatly appreciated. Please keep in mind that I am new to this technology and a novice at best. Thanks!

Best Answer

The fluctuation of the BlueTooth signal is probably too strong to get 60cm/2 feet precision. You could combine several sensors to create the effect, though.

  • Use BLE to discover that the object is within 10m, provide security and wake your device.
  • Work with light sensors, motion sensors, gyroscopes, etc to guess what is happening up close and animate/react.

Can you share more details about your project?