Compiler/TMS320F28035: How I can load LUT to create a sinusoidal with ePWM outputs

S.Ibarra

Intellectual 655 points

Part Number: TMS320F28035
Other Parts Discussed in Thread: CONTROLSUITE

Tool/software: TI C/C++ Compiler

Hi All

I need to load a Look-up table in flash memory to generate a sinusiodal signal with the ePWM outputs.

I am using the TMS320F28035 microcontroller and CCS V7. I read several references but this don´t say how to do that.

Thank in advance.

Sebastian

over 8 years ago

0 Long MaX over 8 years ago

Intellectual 270 points

Hi Sebastian,

You can use Excel or other tool to precompute the values of sinus table for 0 to 2π. The step depends on your need. Declare a constant array containing these values in a source file. Use this array when computing the pulse width of the ePWM outputs after normalising the time within the interval 0 to 2π.

Regards,
Long.

0 S.Ibarra over 8 years ago in reply to Long MaX

Intellectual 655 points

Hi Long

My issue is how I can load the 500 values that syntesis the sinusoidal signal. I have that values but I need to load such 500 values to memory then put them to ePWM registers.

Thanks for your answer.

Sebastian

0 Cody Watkins over 8 years ago in reply to S.Ibarra

TI__Mastermind 42195 points

Sebastian,

look at this post to see how to load the LUT into memory.

https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/205736?tisearch=e2e-quicksearch&keymatch=creating%20a%20look%20up

You won't be able to just simply "put them to ePWM registers" you will need to preform a small amount of math, use the LUT and update the PWM's period. You can update the PWM many different ways depending on how you have configured the PWM.

The PWM module is complex, but if you read through the user guide and look at the examples provided in controlSUITE then you should have it working in no time!

Regards,
Cody

C2000™︎ microcontrollers

C2000 microcontrollers forum

Compiler/TMS320F28035: How I can load LUT to create a sinusoidal with ePWM outputs