treahuggs:
The project states i have to use angle.
If your solution design has be defined for you, that does rather change things. How much of the solution has been specified? I have doubts about the practical usefulness of the solution based on roll angle. What form does your solution need to take? Do you need to show it working on a physical bike? I think you will need to look for a solution using a gyro to detect roll. Depending how well you want this to work you mighty be able to get away with just looking for a change in the roll angle over a short interval, and the gyro will give you that. But you may well find you need to know the absolute roll angle as well, to detect crossing through straight ahead, and to deal with high speed situations where the roll angle and rate of roll are very small. In that case I suspect you'll also need an accelerometer to compensate for drift in the gyro output. Basically, you need to read up on the control algorithms that have been developed for flying drones such as quadrotors. There's been a lot of work done and people have solved the problem quite effectively, but the solution will take a lot of work just to understand let alone get working in your application.