Timer unit initialization
Currently, the spin board (SPIN_v_0_9) can't use timer A and B to generate pwm signals. This PR will allow us to use the correct timer unit according to the hardware version :
- With O2 v1.1.2 we will use timer A and B.
- With SPIN V0.9 we will use timer A and C.
This PR will also add some minor functionality :
- Taking into account the case where the phase is negative in the function for the phase shift.