A small proof of concept has been done so far. Some extra items are missing:

• Shifting back to the 32u4 to benefit from the SD card and standalone FFT -> I need to have the ADC go faster for the acquisition, and to get the data compressed a way or another for longer acquisitions, but that should be feasible.
• Developing a more simple GUI for the OLED screen: I should be able to know when the signals are being recorded, and, if possible, how the beacon is encoded.
• Saving: when a signal is detected, the data should be recorded to the onboard SD card.
• Mapping: with a timestamped data, I'd be able to map on a geographical map the location of the beacons, and why not have a collaborative map ?
• Spoofing: when a beacon is detected, why not send a louder signal saying "HEY GUYS I KNOW YOU'RE LISTENING SO HEY THERE!", to outpower the actual beacon?