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epicjr77
11-03-2009, 01:16 AM
Hello,

I am trying to use trunigy brushless motor/ esc combo to power my project.

If i give the command pulsout 14, 600 the motor doesn't spin

If i give it pulsout 14, 750 it does spin

It will not spin at anything higher than pulsout 14, 1100

my boebot with servos act completely different = puseout 750 is zero spin
anything low spins one direction anything higher spins another

any idea why?

allanlane5
11-03-2009, 01:27 AM
Because the "750" number is for a BS2 "plain", but you have some other "flavor" of BS2, like maybe a BS2sx?

The actual specification is a 1.5 mSec pulse is 'zero', where 1 mSec is "full reverse" and 2 mSec is "full forward" (I could have those backwards). The BS2 "plain" uses 2 uSec per count, so 750 * 2 usec == 1.5 mSec.
However, other BS2 "flavors" use different values, and so the 'count' number needs to be adjusted.

For instance, the BS2sx uses 0.8 per 'count', so 750 * 0.8 == 600 uSec, which is completely wrong. 1.5 mSec / 0.8 uSec == 1875.

Note you STILL have to maintain the 20 mSec delay between refreshes -- trying to reduce that 20 mSec doesn't help.

epicjr77
11-03-2009, 08:45 AM
i am using the regular bs2 , puslout 750 works with the BOE i think my esc might have some type of logic in it

icepuck
11-03-2009, 09:27 AM
Does your esc have any special setup requirements? such as being trained to a radio first or pc software?
If you can get a continuous rotation servo to work with your stamp you should be able to use an esc.
When I was trying to get my Novak roaster esc to work, the problem I ran into was with the bec. I removed the red wire so all I had was ground and signal, then everything worked just fine. The bs2 apparently didn't like the power coming from esc.
-dan

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Arguing with myself--sometimes me, myself, and I don't always agree.
(Former) Caterpillar product support technician

W9GFO
11-03-2009, 11:05 AM
epicjr77 said...
Hello,

I am trying to use trunigy brushless motor/ esc combo to power my project.

If i give the command pulsout 14, 600 the motor doesn't spin

If i give it pulsout 14, 750 it does spin

It will not spin at anything higher than pulsout 14, 1100

my boebot with servos act completely different = puseout 750 is zero spin
anything low spins one direction anything higher spins another

any idea why?


So 600 the motor is stopped, 750, it is turning, and by 1100 it stops? That sounds about right. A typical RC system will have pulse width from about 1.100 mS to 1.900 mS (give or take).

PULSOUT 600 is equivalent to 1.200mS where you say the motor is stopped. That makes sense.
PULSOUT 750 is equivalent to 1.500mS where you say the motor is running. That makes sense too. 1.500mS is the center of the range of pulse widths.
PULSOUT 1100 is equivalent to 2.200mS where you say the motor stops. That also makes sense because the ESC may consider that value out of range.

The other thing is, does your ESC have reverse? Many don't.

Rich H

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The Simple Servo Tester, a kit from Gadget Gangster. (http://www.gadgetgangster.com/206)

epicjr77
11-03-2009, 10:33 PM
I know my esc doesn't have reverse so I am assuming I have a working range between pulsout 500 to pulsout 1000

allanlane5
11-04-2009, 02:12 AM
The ESC (Electronic Speed Control) may also have a 'brake' setting -- but you'll have to check out the ESC documentation to be sure.