The detail of this project can be found at my personal blog
This Mecanum Wheel Robot car is based on an Android application that enables user to control its speed and direction. The PID control program can make sure the car can always maintain the required speed on any floor regardless of friction. Bluetooth HC-05 is used to communicate between the phone and main controller. As one of the field buses, CAN bus is used to communicate between main controller and 2 motor controllers.
You can watch the demonstration video here:
There are totally four buttons on the Android app. The left turn button and the right turn button on the left part are used to turn around the car, but the user needs to constantly press it. The 8 directional movement button is on the right part of the android app, each direction has 45° difference.
The Bluetooth button is on the top right corner of the app, which is a switch of the Bluetooth.
Main Control Unit (MCU) is responsible for establishing the communication link between the mobile application and the Motor Controllers (MC).