Abstract: An imaging capsule, including a radiation source, a collimator that provides a collimated beam from the radiation source, a detector configured to detect particles resulting from X-ray fluorescence and/or Compton backscattering in response to the collimated beam, a motor to rotate the collimator and detector around an axle to scan a partial or full inner circumference of a user's colon with radiation, wherein the motor comprises a segmented commutator that is fed with a power signal via brush contacts; and wherein the motor provides a pulsed output signal based on mechanical switching of the segmented commutator on the brush contacts, providing an indication of the rotation angle of the motor as a function of time.