CCS/LAUNCHXL-F28379D: Problem with FCL_379XL PWM generation

Mahdi Ranjbar

Prodigy 20 points

Part Number: LAUNCHXL-F28379D
Other Parts Discussed in Thread: DRV8305

Tool/software: Code Composer Studio

Hi,

My hardware: a LAUNCHXL-F28379D + 2x DRV8305 Booster boards + the TI's coupled PMSM motors

two boosters are connected to a 30V power supply.

I am trying to compile FCL_379XL example. In the manual, there are 6 levels of compilation and I'm stuck at level 1. At level 1 the program tries to check the correct operation of the PWM channels and SVGEN module. I was able to see the correct waveform for Ta, Tb, Tc, Tb-c in CCS. I was also able to capture the signals on the PWM DAC pins. But I cannot receive anything on the PWM pins.

I know that the driver is alright because it shows the error when I lower the input voltage but the microcontroller does not generate any PWM signal.

Any ideas?

over 5 years ago

0 Ramesh Ramamoorthy over 5 years ago

TI__Mastermind 27240 points

Surprising, check if the CMPA register is getting updated, or, if any trip has happened (TripFlagDMC in the motor1/2 struct). Reset ClearFlagDMC and try.

0 Ramesh Ramamoorthy over 5 years ago in reply to Ramesh Ramamoorthy

TI__Mastermind 27240 points

Let us know if your concern is resolved already, if so, you may close the thread.

0 Mahdi Ranjbar over 5 years ago in reply to Ramesh Ramamoorthy

Prodigy 20 points

Hi, no my problem is still present. We didn't want to spend more time on that and we ordered another board that has insta-motion capability.

I checked the trip flag and played with it. I played with the encoder calibration parts too to make sure it is not stuck there. I commented the place that calls the protection functions as someone said in another thread. Still not getting any PWM on microcontroller's pins. I have output on DAC pins which is surprising. Because it's just a low passed PWM and I am not getting any PWM on the PWM pins.

0 Ramesh Ramamoorthy over 5 years ago in reply to Mahdi Ranjbar

TI__Mastermind 27240 points

Well, you could pull out the booster packs and just try it with powering from the USB for build level 1. After commenting out the DRV8305 initialization, build level 1 should give out PWMs.

If you had already moved past this demo and are not going to evaluate this demo any further, pls close the thread. Thanks.

0 Pavel Grekov over 5 years ago in reply to Ramesh Ramamoorthy

Prodigy 60 points

I have the same problem. Help me please

0 Ramesh Ramamoorthy over 5 years ago in reply to Pavel Grekov

TI__Mastermind 27240 points

If you do not have the booster pack mounted, then the analog protectio may block the pulses. It looks for current feedback within a range of, say, 1.65V+/-delta, this delta is around 1V. If you dont have the booster pack mounted, it may bring down the voltages on the analog inputs of MCU to near 0V which is a fault indication.

You may want to comment out the protection function in the code and see if that helps.

0 Pavel Grekov over 5 years ago in reply to Ramesh Ramamoorthy

Prodigy 60 points

If you just comment on the protection function, BOOSTXL will not turn off, but THIS does not solve the problem with PWM.

0 Ramesh Ramamoorthy over 5 years ago in reply to Pavel Grekov

TI__Mastermind 27240 points

In the protection function, CMPSS is set up to monitor o/c conditions to generate TripFlagDMC. This is just to see PWMs showing up on the pins, which may be disabled in the flag is set to 1. Hope it helps.

From your other post, it appears that you found the solution. For the sake of others, am showing that thread here.

https://e2e.ti.com/support/microcontrollers/c2000/f/171/p/907971/3364576#3364576

With this, am clsoing it.

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CCS/LAUNCHXL-F28379D: Problem with FCL_379XL PWM generation