Early Warning for Protesters using Raspberry Pi

[loreanvictor]

Isn't it possible to configure a Raspberry Pi equipped with a microphone (something like this) to emit some radio signal (example) whenever say a bunch of motorcycles pass by? If so, such a device could be used by protesters as an early warning system (using a pocket radio like this).

Pros:

• All necessary hardware available in Iran, so with some easy to run processing code people can setup such devices easily.
• Radio seems like the only feasible method of communication for protesters, since internet access is cut off or severely limited in protest areas, bluetooth has an extremely short range, and it is a general security risk for protesters to keep their mobile data / WiFi / bluetooth turned on during protests.
• The board can automatically broadcast whenever it detects the signal from a safe distance, without requiring any human supervision, lowering its operational risk.

Cons:

• Requires technical knowledge to setup.
• It is not cheap to produce (around ~7M per device), and devices might regularly get lost / destroyed (would the security forces be able to locate the device during transmission?)
• In some situations normal traffic might result in false alarms (specifically for daytime protests in areas with lots of motorcycle traffic).

Steps

• Some processing code that can be cloned and run on a board
• Some nice instruction webpage to allow people not from a technical background to build their own boards
• Testing (obviously)