Hello,
I am playing a little with the pwm frequency for the motor in the arduino sketch. But I am not really happy with these options we have. At the moment I use 122.55 Hz. My motor does not make high frequency noise any more, but it does not seem to like that pwm-frequency as well.
So I took a look at the sketch and saw that there are 2 values that are used to change the pwm-frequency:
-TCCR1B for pin 9 and 10 and
-TCCR2B.for pin 3 and 11
But I use the cytron only on pin 3, so I think it should be possible to use the other pwm-frequency options like 245,10Hz fro TCCR2B?
Is that right? OR is there another rason why TCCR1B needs to be set to exactly the same frequency? Is it only for IBT2?
Update:
So I just tried out the TCCR2B frequencys and my thougt was right. For the cytron only this needs to be changed. The TCCR1B is obsolete.
So now I changed the value of TCCR2B to 31372 Hz and this works great with my motor. No more annoying sounds and perfect reaction.
The code that needs to be changed is easy to find on the internet.
Maybe this advise can help someone here.
PWM frequency is also discussed for hydraulic valves.
Hello ,
In your opinion, what would be the consequences for a brushed motor and autosteer to lower the pwm frequency to 30hz? Because at 490hz, it is really whistling. This is the type of engine I have in mind:
Maybe take a look here as well: INO for 10 bit PWM resolution on Cytron
I used the Timer1 library to increase the PWM resolution, as a side result you get an easy way to change the frequency without messing with the registers directly.
Hi Tooki,
maybe you misunderstood something. I raised the frequency to 31372Hz. I also tried with lower frequency than 490, but that didn´t work.
But your motor seems to be much too fast with 3000 rpm. It should be around 300 rpm.
Hello,
I understand what you have achieved, my question is more about the consequences for a motor of a change of pwm. Because on the test bench, low pwm is much less noisy and annoying.
Is it too fast? yes and no, the ideal is to turn the steering wheel correctly up to 100-150rpm. So everything depends on the gear ratio that we put between the engine and the steering wheel. I’m just doing some tests, I would like to succeed in putting a motor without reducer. because geared motors like the phidget or others end up wearing out slightly and making an unpleasant “ticking” noise at each change of direction.
Another solution would be a stepper motor.
Ok, I see, you have made yourself some ideas about it. That is good. Finally everbody who does not do Copy and Paste of the system, has to find out which way works. I tried out 3 different motors before finally taking the Trucomponents-motor. And you are right it depends on the gear-ratio, but how do you want to bring the rotation on the steering wheel?
By the way, I have no idea about the right frequency for the motors. I think in the manual to my motor was some information, but I also did “Try and Error”.