A stepper motor is used to rotate the lidar to perpendicular to its own movement, thus creating a three dimensional view for the lidar to record.
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The stepper motor is controlled via PWM on Timer 9, and the processor receives an interrupt for every step taken to keep track of number of steps (0 - 400). At every lap, a hall effect sensor gets triggered, which induces an extended interrupt on GPIOG Pin 3 to reset the step counter.
A stepper motor is used to rotate the lidar to perpendicular to its own movement, thus creating a three dimensional view for the lidar to record.
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The stepper motor is controlled via PWM on Timer 9, and the processor receives an interrupt for every step taken to keep track of number of steps (0 - 400). At every lap, a hall effect sensor gets triggered, which induces an extended interrupt on GPIOG Pin 3 to reset the step counter.
The transmitter sends radio signals to the receiver, which converts these into PPM signals
that the run on 8 different channels for controlling the copter. To be able to apply
automatic control to the quad, we need to modify these PPM signals as we'd like them.
PPM is basically pulses of different width, that correspond to different amplitudes of
input (throttle, pitch, yaw, etc). For this purpose of control, a separate timer (TIM2 CH1) for input capture is impemented. Pulse width measurement is accomplished in the same manner as with the sonars, Input capture interrupts call the function \emph{ppmDecode()}, which in turn
call the function \emph{computeWidth} and stores the pulse widths in an array, \emph{pulseArray}.
When the array is full (8 pulse widths), the function sends it to \emph{MSP\_newRCData} for
