• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 31 subscribers
  • Views 416 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV10983: Direction control over i2c?

Thomas Bewley
Expert 1030 points
Part Number: DRV10983
Other Parts Discussed in Thread: DRV10987Sec 8.1 in datasheet says that “ TI designed the interfacing to the DRV10983 to be flexible. In addition to the I2C interface, the system can use the discrete FG pin, DIR pin, and SPEED pin. SPEED is the speed command input pin. It controls the output voltage amplitude. DIR is the direction control input pin. FG is the speed indicator output, which shows the frequency of the motor commutation.” Sec 8.5.3 in datasheet then says that “If OverRide = 1, user can directly control the motor speed by writing to the register through I2C.” Clear enough. Based on the above high-level description in Sec 8.1, I was hoping the commanded motor DIRection could also be set over I2C, but based on what registers are available to write to this does not actually seem possible at this point, is that correct? Is this a feature that could be added to this IC via a simple firmware upgrade? It seems like it would only use a few bits, and there are already several available writable bits that are currently unused? I’m not clear why this isn’t already possible, you guys must have thought of this use case already? Thanks for the feedback. This seems like a pretty remarkable IC...
  • 0
    TI__Mastermind 18900 points

    Hello Thomas,

    Thanks for posting on the Motor Driver forums and taking interest in the device.

    The short answer is that it is not possible to override the pin functionality and control the logical input via I2C. 

    The longer answer is, to your point, the Override bit does this with the SPEED pin, the MotorSpeed and MotorPeriod registers do this with FG, but we have no equivalent with DIR. Because the device is fixed function and not an open core (and more of a state machine implementation) updating the device's aglorithm and functionality is not as easy as updating the FW in an MCU or processor. It requires reworking quite a few layers of metal in the actual design of the device. You can think of it as the flexibility in making changes has decreased, but the performance (speed and efficiency) has increased and cost to manufacture has decreased.

    The DRV10983 was made in 2014, which considered old by TI's standards (I suggest taking a look at DRV10987 which added some features and improved on the existing architecture and see if its worth to "upgrade to a newer generation"). We have heard about the kind of feedback, and our next generation will certainly have this feature as there is a lot of benefit to populating less traces and components around the device. 

    Best,

    -Cole

    P.S. This also includes the feedback for configurable I2C Secondary (formerly known as slave) ID, but I will let someone else comment on that thread.

  • 0 in reply to Cole Macias
    Expert 1030 points
    Hi Cole - Thank you for the detailed and clear feedback. I see that the DRV10983 was from 2014 and the DRV10987 from 2017. Is it possible to ask you a question (offline) about the likely timing of their next generation, which you hinted towards? I’d like this particular motor control board that I am designing (along with a family of several other voltage regulation + motor control boards highlighting TI ICs) to serve as a long-term reference solution (for RPi-based educational settings), and am not in a particular rush to get this particular one out the door. I’d rather not commit to a DRV that is effectively about to be superseded. (I am not sure the best way to share my email with you?)
  • 0 in reply to Thomas Bewley
    TI__Guru 65470 points

    Thomas,

    Please request my friendship on E2E and we can discuss in PM, I am not sure what I have to share but I would like to close this thread if you have no other questions other than roadmap.

    Regards,

    -Adam