still tryin to hack servo code

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Dr_Doggy

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between my receiver and the ESC is a 1-2ns pulse /20ns which sets the speed, say I wanted to "stretch" that signal so that its a little wider, so that it goes a little faster than the transmitter commands.

would a capacitor in parallel force that stretch? (just a little one(0.1ns additional))
 
No, a capacitor will not do anything. Note also that the figures should be milliseconds not nanoseconds.

Mike.
 
ya, ms, thnx,

what about if i put a cap on to quick charge then a resistor to slow discharge? maybe a diode in there?

is there a simple plan B?
 
im actually using a BLDC, but the controller uses the pulses similar to a servo, 1-2ms/20ms, actually im using 4 BLDC motors, so keeping them at the same speed is difficult, so i want to run them off the same pulse, , but then in order to balance my device i need to use a remote switch to give the motor a kick once in a while, off a trigger on the device, so when the trigger is hit it needs to take the input pulse then make it a tad bit longer,

i just want to stretch it out a bit...

I once saw in a radio tutorial a schematic that used a configuration as a hold latch (that holds a walkey talkie on TX when an audio signal is present..and a second after),,

I was hoping to do something similar here...?
 
You will never keep 4 BLDC motors at the same speed without separate feedback for each and a dedicated closed loop control system for the whole thing. You will never be able to balance them using standard servo signals, while the servo's themselves will drift from thermal effects and there is no feedback from outside the servo's themselves. You're trying to close the loop without feedback, a simply delay will NOT work.

You need a real control system not a hobby servo based one.
 
ya, servo signal it is, the hobby store gave me it, the receiver uses pwm. it is so that it can be universal for servos and BLDC controllers, when the throttle on transmitter is at low , receiver emits short pulse, as i increase throttle pulse widens.

I would hook up all motor controllers to one receiver channel to maintain balance but then they all do the same thing,but then i need a way to steer,

Ideally i'd like to use ch1 for my height, and channel 2&3 for my directions, maybe i could use logic gates to sum the 2 channels?

and whats this about feedback? what kind of signal is that>? how do i see what it is feeding back?
 
If you need precise mapping to the different ports like that the only pratical way is to use a micro controller, manipulating servo signals on a micro controller is not complicated and it alllowes a nearly unlimited ability to mix the channels any way you want with high precision. Feedback come from whever you get it, in the case of a hobby servo motor the feedback signal is internal and not generally accessable to you, it's the position of a potentiometer that is used to figure out what the position of the servo is. BLCD's generally don't have any feedback mechanisms at all.

The 'kick' you're talking about to keep your robot in balance is feedback, it just happens to be provided by you, in control systems you would use a sensor such as a rotary encoders or pots like servo's do to feed into an electronics circuit so that it knows it's own state and then it can adjust it's own motor signals to allow it to maintain whatever state you program it for.
 
lol, nope, my first step in robotics was just the other day, and i used steppers, I never knew there were so many types, before i thought it was just ac and dc motors!
 
Stepper do not have ANY feedback, you're trusting that the signals you're delivering will result in the correct position/number of steps. A servo requires feedback of position to the controller.
You can toss a rotary encoder on a stepper so that you truly know what the position is but it depends on your needs, steppers work quiet well in a large number of situations.
Keep in mind a fast feedback controller using good sensors on the motors or sensors themselves have allowed the development of things like the Segway and autonomous flying vehicles. Sensor technology has increased by leaps and bounds in recent years.
 
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lol,ima teach these lil guys to turn off televisions!
 

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I think you'll have problems with the control systems in the long term =) The motors specifically. nice goal though.
 
ya, cant fly it with the remote, each stick is per motor, thats why ima let it balance itself, use the remote for a command structure, so when i get PIC i can feed in on 1or2 channels instead of all 4

.......don't know how i'm going to automate height yet ........
 
what about this? would it work? I'm using J1 as my balance sensor, and the clock is my pulse signal
 

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.......ohya..... what would happen if i send pulses that have a low off time? ie; a 3ms +/-1ms clock with 50%duty cycle? could a servo keep up with the data with little off time?
 
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