== Quadrature Decode ==

The Quadrature Decode uses two eTPU pins to decode a signal from an [[https://en.wikipedia.org/wiki/Rotary_encoder#Incremental_rotary_encoder|incremental rotary encoder]]:

{{attachment:pdx_quadraturedecode_diagram1.jpg|Quadrature encoder and generated signals|width=500}}

=== How does quadrature decode work? ===

The OpenECU platform provides two blocks:
 * [[doc_user/openecu_user_guide_simulink_chunk/pdx_quad_input.html|pdx_QuadratureDecode]]
 * [[doc_user/openecu_user_guide_simulink_chunk/pdx_quad_freq_input.html|pdx_QuadratureDecodeAndFrequencyInput]]

These blocks will automatically decode the input and report the number of edges sensed. A positive number indicating forward rotation and a negative number indicating reverse rotation.  The Latter block also senses the frequency of the input waveform.

 * Click the links above for more details

If you are having difficulties, see [[Scope Trace Looks Good No Input|our page on troubleshooting PWM and frequency inputs]].