PWM servo
ervie
Posts: 13
Hello,
I have a question about the PWM object. The following is said in the manual(p184, 204 in the PDF) about the PWM object :
To set the duty cycle to 50%, for example, you’d set the high time and low time to be 1 (or any two equal numbers from 1 to 255).
Why have servo's a larger lowtime than the maximum of 255 ? I'have always used 2304 as my lowtime and it worked perfectly.
I am asking this question because i am working on normal motor with the L298 controller, and it isn't working yet. The PWM seems to be the problem.
Thanks,
ervie
(I hope you understand my english...)
I have a question about the PWM object. The following is said in the manual(p184, 204 in the PDF) about the PWM object :
To set the duty cycle to 50%, for example, you’d set the high time and low time to be 1 (or any two equal numbers from 1 to 255).
Why have servo's a larger lowtime than the maximum of 255 ? I'have always used 2304 as my lowtime and it worked perfectly.
I am asking this question because i am working on normal motor with the L298 controller, and it isn't working yet. The PWM seems to be the problem.
Thanks,
ervie
(I hope you understand my english...)
Comments
The system tick for the javelin is 8.68 microseconds.
20msec/8.68usec = 2304
1.0msec/8.68usec = 115
1.5msec/8.68usec = 173
2.0msec/8.68usec = 230
Since pulsewidth is much smaller than 20msec, you can keep the low time constant.
regards peter
It really proved usefull, our L298 works good at the moment. The post gaves us more insight in the electronic device.
We made a mistake with the batteries, the were empty...