Flexible / DIY (there is no company behind, that first needs to figure out if there is a market potential before creating a specialized sensor).
I can make whatever sensor that I want. For example, I have build mysensors into my garageport opener. And I have plans to sensorize the chicken coop, and the chickens themselves.. Monitoring stuff that you never knew was possible in your wildest fantasy..
I probably need to think about security, but that's not the top priority right now..
Well, it's more a bt distance monitor. It is only monitoring a single device, while you would need to keep scanning the surroundings at regular intervals and report all devices in range with signal level, then filter only the ones you registered
@Tmaster I am not doubting the principle of increasing effective radiated power by way of relocating the antenna, or improving the radiation lobe in a set direction. The additional gain is important with weak signals at both send and receive ends, but at 50m it should not be an issue at these frequencies unless there are major attenuations to the signal. I have to guess you already have a dipole at the receiver ?
I use the Easy Newbie boards for most of my projects. It is designed for the nRF24L01+, and it has space for the needed 3.3v regulator if you are running it at 5V. I don't know if he has a way of using it with the RFM69 radios, but you could check. Plus it has a small proto-board area for wiring your sensors. Kudos to @sundberg84 for the design.