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F28069M: Resolver interface

Stark
Intellectual 420 points
Other Parts Discussed in Thread: DRV8301, PGA411-Q1, TMS320F28069M

Hello Tom,

I need you advice. can you please help me?



I want to control my outFlowValve and for that I am using 2 BLDC(Brushless DC) motors. Both the motors have Resolver for position feedback and I want to control my motors with Resolvers only. I am working on real time application and I need to have accurate position of motor at zero speed. So that is why I need to use both the motors with their resolvers as a position feedback.

I am using sin/cos resolver (Reluctance type Resolver).

Motor has 6 wires for resolver. Two for sin (SIN_HI & SIN_LOW), two for cosine (COS_HI & COS_LOW) and two for Excitation.



As I am going to use F28069M lauchpad with two DRV8301 booster pack to control two motors simultaneously, So I needed to connect both the resolvers of motor to that lauchpad .



My Launchpad has two QEP (quadrature encoder) interface so can I use for resolver? Now How can I connect both the resolver to both the QEP interface that is on Launchpad?



Can I use PGA411-Q1 chip, I am quite confused how to use it. So how can I use it to connect resolver to encoder? To use breadboard, can we use this chip to connect? I cannot solder it to my Launchpad even. I don’t know how to do it.



I am not the HW guy so I am sorry but if you can help me then it will be very helpful.



Is there any solution for regarding resolver interface for the products that I have?



Regards

Rahul Lukhi
  • 0
    TI__Guru**** 182421 points

    Hi Rahul,

    The QEP inputs of the TMS320F28069M are digital while the outputs of your resolver are analog, so you can't simply connect them together. The F28069M has the ability to simultaneously sample its ADC channels so I would start there - try to measure SIN and COS simultaneously and then do the math to get the position detail from the ADC results. I've never used the PGA411, but with a quick look over the datasheet, it appears to have a quadrature encoder emulation mode, so that may be an option for you. Bread boarding the PGA411 may be a bit optimistic - you would need to use the internal signal generator to get the excitation for your resolver and that might get messy without a proper printed circuit board.

  • 0 in reply to Tom Hendrick
    Intellectual 420 points

    Hello Tom,

    Thank you so much for advice.


    As you have said that i can take resolver's output and use ADC pins to convert Analog to digital value and then measure the angle. But can you tell me how would I excite the resolver from my F28069? can one use PWM channel to give 10kHz freq. to resolver?

    I am confused how to deal with this HW thing.

    Regrads,
    Rahul

  • 0 in reply to Stark
    TI__Guru 57255 points

    Hi Rahul,

    I've added some comments on potential implementation at the below:
    https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/641587


    Thank you,
    Brett