PAC ( Personal Anti-Collider ) is a small custom hardware device especially made for this Challenge ( in the last 1-2 weeks :) ) , which communicates in a mesh network by broadcasting kinematic parameters of a vehicle/pedestrian ( velocity vector ).

It is meant to prevent collisions in the blind spots, by using almost standard smart gadgets hardware.

Is fast, is personal, and is most useful in the future of a more messy/crowded traffic system! :)

Now you can see the first prototype of PAC and some tests into a web simulator here:


  1. works in blind spots ( the collision is detected by exchanging data over radio, so it can see "over the corner" )
  2. low latency ( because is working in a local RF mesh network, not depending on a remote server )
  3. generic algorithm ( it doesn't stick to a map or a localization service - that's why it can be used in "out of the grid" regions )
  4. is standalone ( can be integrated on vehicles, or older smartphones without WiFi P2P capabilities, just by using the Bluetooth connection; more, it has its own power supply - don't have to squeeze your phone battery to keep it alive ;) )
  5. is just making a broadcast'n'listen simple mesh network ( meaning that the communication is not needed to be full-duplex; it doesn't relay on specific addressing in the mesh, so the network layer is minimalist and the auto-discovery is easy to implement )
  6. more accurate then phone's sensors ( the orientation is given by dedicated IMU )
  7. open protocol, small payload ( now it sends only 16 bytes, LAT/LONG position and a relative to North angle )
  8. can be part of your smart gadget ( it just takes to integrate a mesh RF transceiver and an application that uses the protocol to raise warnings )
  9. is scalable ( it can use neighbourhood nodes as relays/cells so that it can expand interaction range )
  10. cheap ( the standalone prototype built on its own PCB will costs around $60 without the battery and case - so in production this cost will be even smaller )
  11. plug and play ( you are in traffic in your car, ridding a bike or just on foot? Is enough to have your PAC on you an connect by your phone to it )


  1. you must buy it as a separate device ( because the WiFi module in the smartphone is not powerful enough to broadcast in larger ranges, and for the lack of dedicated WiFi P2P capabilities in majority of wireless devices )
  2. usage not generic ( all the involved traffic participants must have PACs so that all can track each other )
  3. need of a secure protocol ( because all the data is transferred through radio, someone can hack it )
  4. it depends on GPS ( the location is given by GPS, so will not work without it; in the future by combining the GPS with IMU the device can estimate the location by inertia, starting for a known position )
  5. false positives ( because now is not taking in account the actual map's roads it can give warnings even if two velocity vectors can intersect in a imaginary place - like inside the liquor store from the street's corner :D )

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