Timeline for Phase and frequency correct PWM mode Arduino Mega 2560
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 5, 2019 at 16:59 | comment | added | Vivek Vijayan | Thanks for your time. I am proceeding with it. Will try some RC filters to identify the output waveform. | |
| Jul 5, 2019 at 16:47 | comment | added | Edgar Bonet | @VivekVijayan: Your phase correct waveform is fine. It looks wrong to you only because you don't understand how your DSO sets its time axis. | |
| Jul 5, 2019 at 16:25 | comment | added | Vivek Vijayan | I don't know much about CRO. I am using an electronic module called Expeyes which basically acts as a DSO. I used the time reference axis to determine the triggering points. Expeyes doesnt have any option to control triggering. I generated Fast PWM using different code and compared it with the output from the above mentioned code. | |
| Jul 5, 2019 at 15:47 | comment | added | Edgar Bonet | @VivekVijayan: You would not get 1 kHz in fast PWM mode. Re "different starting points (in time)": What is your time reference for defining the starting points? Are you using an oscilloscope? If so, how did you configure its trigger? | |
| Jul 5, 2019 at 14:42 | comment | added | Vivek Vijayan | @Edger Bonet: I am getting the expected frequency. But when I observe the waveform all the waves with different duty cycle starts from the same point. I believe in phase correct pwm mode the OCnA or OCnB pins are set during upcounting. So I could expect different starting points(in time) for waves with different duty cycles | |
| Jul 5, 2019 at 14:19 | comment | added | Edgar Bonet | @VivekVijayan: Do you get the expected frequency? If so, how do you tell it is not phase correct? | |
| Jul 5, 2019 at 13:47 | comment | added | Vivek Vijayan | When I added interrupt service routine (ISR(TIMER4_COMPA_vect)) the output waveform acts exactly like fast PWM. It does not provide phase correct wave | |
| Jul 5, 2019 at 10:08 | history | answered | Edgar Bonet | CC BY-SA 4.0 |