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EK-TM4C1294XL QEI

Maria Wahono
Prodigy 170 points


I never use LaunchPad before, but I am planning to after I look at the specs of this product. I am in need to use a rotary encoder and processing a huge matrix calculations controller simultaneously. This product seems to have the right specs, I have browse the videos on the QEI, but I am still confused. So here is my questions:

Does the QEI module have its separate pins, or i can just use ordinary I/O pins and use a provided library?

What exactly is the QEI? does it process the quardature inputs automatically? By what(a provided library or what)?

  • 0
    TI__Guru**** 244410 points

    Hello Maria,

    1. QEI Module pins are multiplexed with GPIO. it has to be configured in the GPIO Module so that QEI module pins can be available to be connected to the output of the rotary encoder

    2. There is gpio.h/.c library function along with pin_map.h that can be used to map the pins

    3. The QEI module can take two types of input: Quadrature inputs from an encoder wheel and compute velocity, direction and position OR it can take a Dir-Pulse input and use to compute the velocity, direction and position.

    Regards

    Amit

  • 0 in reply to Amit Ashara
    Prodigy 170 points

    Thanks Amit,

    I have another question, do the Hercules series the eQEP (Enhanced Quardature Encoder Pulse) does the same thing as QEI?

  • 0 in reply to Maria Wahono
    Guru 27285 points

    Maria Wahono said:

    Thanks Amit,

    I have another question, do the Hercules series the eQEP (Enhanced Quardature Encoder Pulse) does the same thing as QEI?

     A quadrature encoder work around two or three signals:

     Phase A (a square wave generating an integer number of pulse per revolution

     Phase B same sa A but but shifted 90°

     Home: is active when in a zero position.

    Every QEI work this way so c2000, TIVA and other processors work same way.