Pulse-length vs degrees vs microseconds

(david) #1

The example code for the T100 with an Arduino specifies values in microseconds to program the ESCs for the motors. However, other SOC boards, with other libraries want degrees or pulse lengths. Having trawled the googles for a while I’m still not sure how to convert between them. Can someone please point to an understandable primer?

thx

(Richard) #2

Pulse length, or pulse width, is measured in microseconds. Pulse width or pulse length is the time in microseconds that the pulse is positive. Just google the terms and you will learn everything you ever wanted to know about pulse width modulation (PWM).

(david) #3

so when I program a value of 1500 to halt the T100, that is the microseconds and the pulse length? Too obvious for my little brain :-). Thanks!

However, that does not help me with degrees. A lot of libraries assume 0-180 degrees. That’s the one I’m having trouble finding a conversion discussion on.

(Richard) #4

David,

I am not familiar with using degrees to describe pulse length. It may be referring to phase shift, but that has to be measured relative to a reference signal. Perhaps you could post a bit of code using degrees to describe pulse width. What is an “SOC” board?

(Rusty) #5

Hi David,

The “degrees” unit for pulses is usually used to make it easy to control servos, which rotate and have a range of 0 to 180 degrees. I would stay away from that, but most libraries should translate 90 degrees to about 1500 µs.

-Rusty

(david) #6

SOC means “System On a Chip”. For example, an arduino is a SOC, as is a BeagleBone, C.H.I.P., ODroid etc. It’s not actually on a chip but that’s the way its used.

(Richard) #7

Okay, thanks.