Difficulty in generating PWM pulse with conditions

ashish ahir

I have generated SPWM wave in F28335 delfino using simulink. Duty cycle is varying continuously in that wave. But, now i want to generate wave as shown in figure.
(1)For half period, it is SPWM
(2)For another half period, it is constant at high or low level.
How to do this?

over 8 years ago

0 Gautam Iyer over 8 years ago

Guru 192875 points

Hi Ashish,

This would depend on your SPWM algo. Also the above waveform is nothing but to modify the CMPx value to max or min of TBPRD value.

Regards,
Gautam

0 ashish ahir over 8 years ago in reply to Gautam Iyer

Expert 1020 points

Hi Gautam,
Thank you. As you said, i did some modification in SPWM algo.
can you please help me with following query.
e2e.ti.com/.../1589823

0 Gautam Iyer over 8 years ago in reply to ashish ahir

Guru 192875 points

Replied :)

0 nadia smith over 7 years ago

Prodigy 80 points

Hello ashish. I'm having difficulty generating a spwm wave in Simulink for the F28335 delfino. I'm using a discrete sine and triangular wave and I do get pwm pulses but when I load the program onto the dsp I'm getting noise and I don't see any pulses on the oscilloscope. I'm not using the EPWM block just the GPIO DO block. Can you show me how to implement the spwm correctly so I can see the pulses on the oscilloscope? Thanks!! you can email me at nsmith242@gmail.com

0 nadia smith over 7 years ago in reply to ashish ahir

Prodigy 80 points

Hi Guatam,

Are you familiar with designing a sinusoidal pulse width modulation in Simulink using the epwm blocks? I went on the matlb forum but I haven't received any responses to my question. I'm using a sine wave and triangular wave and I send the outputs to the gpio d0 block. I was reading through this thread and it looks like you're recommending using the epwm block to design the spwm.

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Difficulty in generating PWM pulse with conditions