The first step for developers was to analyze how the VIO communicated with the smartphone. By setting up a "Man-in-the-Middle" (MITM) proxy, hackers could intercept the Bluetooth traffic between the phone and the VIO unit. This revealed the proprietary protocol TomTom used to send map data and turn-by-turn instructions to the display.
If you are attempting to hardware-hack or reverse-engineer the unit, these are the core specs: TomTom VIO discontinuation Tomtom Vio Hack
The Vio was unique for its round, glove-friendly touchscreen and its reliance on a smartphone app for GPS data. When TomTom pulled the app from stores and stopped map updates, the hardware became "bricked" for most users. The core of the "TomTom Vio Hack" movement is not about malicious intrusion, but about . 1. The Smartphone Connection Hack The first step for developers was to analyze