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TMS320F28379D: Using a third PMSM (inverter/eQEP) to the LaunchXL: is there a third set of all necessary peripherals?

Prodigy 155 points

Replies: 8

Views: 129

Part Number: TMS320F28379D

I asked this question in a resolved thread but I think it is a topic deserving of its own thread. Regarding the possibility of controlling a third PMSM with QEP, assuming it uses a 3-phase inverter, I have several questions:

  1. The LaunchXL BoosterPack for the TMS320F23789D has many interfaces (I2C, UART, SPI, ADC, DAC, PWM etc).  To build on the FCL code developed for the two-motor control and add commands for a third motor, do we need ALL of these interfaces on the third set of connectors?  Perhaps only some are needed to control the third motor?
  2. The TMS320F28379 has the capacity to connect to a third QEP channel, but what is the availability of the other interfaces?  For example, I checked the I2C, and it seems there are only 2 channels on the processor, so there is not a third channel for the third BoosterPack connectors. What about PWM; I know there are 24 ePWM channels (enough for 3 PMSMs) but only 16 HR-ePWM channels (not enough for 3 PMSMs). Which type of ePWM is being used for the PMSMs?
  3. Do you have (or have access to) the Dev board schematics and board layout?  I did see that there is a schematic and prints of the layers in the production data pdf, but having access to the original/latest design files form TI would be very helpful. (I see these are available for the BOOSTXL board, but couldn’t find them for the Dev board).

Thanks again.

  • 1. To control 3 motors, the Launchpad setup may not help. You may have to custom design a board. You need PWMS / ADC/ QEP for each motor. The lauchpad supports only two as you know already.

    2. If you are under the impression that an I2C is needed for each motor, then it is wrong. What is needed is given above. 

    3. What do you mean by dev board?  For the launch pad, the schematic files are available through C2000ware. If you did the latest install, you will find it at

    C:\ti\c2000\C2000Ware_2_00_00_02\boards\LaunchPads\LAUNCHXL_F28379D\R2.0\design files

  • In reply to Ramesh Ramamoorthy:

    Ramesh Ramamoorthy
    1. To control 3 motors, the Launchpad setup may not help. You may have to custom design a board. You need PWMS / ADC/ QEP for each motor. The lauchpad supports only two as you know already.

    Yes, I know this. I am talking about developing a custom board with a third set of connections to interface to the encoder and inverter of a third PMSM. 

    Ramesh Ramamoorthy
    You need PWMS / ADC/ QEP for each motor.

    I know the TMS320F28379D has enough QEP connectors, but does it have enough ADC and PWM connectors for a third motor?

    Ramesh Ramamoorthy
    If you are under the impression that an I2C is needed for each motor, then it is wrong

    Good to know, thanks!

    Ramesh Ramamoorthy
    What is needed is given above. 

    What do you mean "is given above"? As I asked previously, can you tell me if the TMS320F28379D has enough PWM connections for a third motor? I know there are 24 ePWM channels (enough for 3 PMSMs) but only 16 HR-ePWM channels (not enough for 3 PMSMs). Which type of ePWM is being used for the PMSMs?

    Ramesh Ramamoorthy
    3. What do you mean by dev board?

    I meant the Launch Pad.

    Ramesh Ramamoorthy

    For the launch pad, the schematic files are available through C2000ware. If you did the latest install, you will find it at

    C:\ti\c2000\C2000Ware_2_00_00_02\boards\LaunchPads\LAUNCHXL_F28379D\R2.0\design files

    Perfect! Thanks!

  • In reply to Zac Milne:

    Of course, it has enough pwms/adcs. 3 EPWM peripherals are needed per motor, and the device has 12. Two/three phase currents per motor need to be sensed through adc, there are more than 20 channels.

    HRpwm is part of the EPWM peripheral, sharing the same pin outs, but you don't necessarily need them if you don't need all that higher resolution. Hope it helps.

  • In reply to Ramesh Ramamoorthy:

    Great thanks! This resolved my issue.

  • In reply to Ramesh Ramamoorthy:

    One last question (hopefully). I want to simply customize a new board to be just like the LaunchPad and use it with the Booster Packs, preferably the BOOSTXL-3PhGaNInv, but potentially the BOOSTXL-DRV8301 or 8305. So, do these booster packs require I2C, UART, SPI, or DAC?

  • In reply to Zac Milne:

    Pls review the user guide for those information that are already there.

    Even if SPI port is not available, they work on default mode.

  • In reply to Ramesh Ramamoorthy:

    OK, but didn't you write the application report "Dual Motor Control Using FCL and Performance Analysis Using SFRA on TMS320F28379D LaunchPad" which uses the Booster Packs with the TMS320F28379D and thus you can tell me the answer? From the BOOSTXL-3PhGaNInv EVM block diagram (given here http://www.ti.com/lit/ug/sluubp1a/sluubp1a.pdf), I don't see any of those signals. Can i assume they aren't required?

    Thanks

  • In reply to Zac Milne:

    Hope you found the answer in the user guide. We are closing this thread.

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