servo motor resets 16f877a

[skimask]

Hi skimask,
Maybe I am always wrong...
Maybe my english isnt good enough...
But I think, it is not shame not knowing it is shame not learning ...
If you wont help me ,dont reply my words please...
When I read your words,I feel like humiliated
Thats all...

Whoa, hey, back up a bit here... Your English is a lot better than my __________ (insert any language other than English here) and completely understandable (if not a bit grammatically incorrect, but that's ok).
What I'm saying is that you aren't listening very well. We believe the core of the problem to be power issues and you keep talking everything but power issues (i.e. code problems, etc) thinking that your power is infallible, when judging from the problems described, it looks like a power issue...for the last 60-ish posts. How long did it take you to finally add a capacitor?
Think what you want, but in the end, I'd bet on a power supply problem...

[burak450]

Whoa, hey, back up a bit here... Your English is a lot better than my __________ (insert any language other than English here) and completely understandable (if not a bit grammatically incorrect, but that's ok).
What I'm saying is that you aren't listening very well. We believe the core of the problem to be power issues and you keep talking everything but power issues (i.e. code problems, etc) thinking that your power is infallible, when judging from the problems described, it looks like a power issue...for the last 60-ish posts. How long did it take you to finally add a capacitor?
Think what you want, but in the end, I'd bet on a power supply problem...

It's not about not listening,its about not understanding..

Sometimes i dont get what all people said because i dont know too much about power issue...

I appreciated what you did for me up to now..But say your word please more polite...

I swap the servos and tried first program(single servo program) which worked perfect...

But stiill remained vibration on up_down servo.I think thats interesting..

There is no vibration or oscillation whatever you called, on left-right servo...

Is this servo broken?

I have to tell you another things...

I connected 9v battery same problems remained...

I tried two parallel 7805 and it makes servo slow because when I tried a single 7805 ,it worked fast...

Thats gonna be a weird question but i want to ask:

Second servo wanna have more current? Or is it broken?

I cant explain why it vibrates...

Finally I tried to connect two servo and tried to work with program which skimask wrote..

Speed was ok but up-down servo vibrated again.Left-right worked well...

I think there is no error in program that you wrote skimask...

But i dont know where the problem is...

[mackrackit]

Try tipping your gizmo on its side, up and down becomes left and right. If that helps then counter balance.

We realy need to see your power supply! Two 7805s slower than one?

Swapping the servos had no change? The up and down servo worked correctly as the left and right servo? If so, the servo is not broken, yet.

[burak450]

I swapped the servos and up-down servo didnt work correctly.It goes up and down but it makes vibriation...maybe that means its broken...

thats my power supply...




and thats 7805 circuit...



and thats two servos..



I think there are two possibilities about my problem
power problem or broken servo...

[mackrackit]

When I say swap the servos, I was meaning physically. If the up/down is used for the left/right, does the left/right action still work.

I I was wanting to see the 7805s in parallel.

But... I still think the problem is power.
The one 9volt 450ma source does not provide enough power for tho whole setup, I think.

That is 450 ma total, yes at 9 volt, start adding two or more 7805s to drop to 5 volt and try to run motors... the amps are just not available.

Do you have another source?

[skimask]

thats my power supply...

I'd get rid of that...and I'd be willing to bet if you hooked up an o'scope to the output under a load, the output would drop off like a rock and just plain look ugly.
You'd be better off with an 8 cell AA NiMH pack of batteries. I would definitely support the load of 2 servos a lot better.
A single 9V battery (the little square ones) or even 2 connected in parallel... That just isn't going to support the load either.

and thats 7805 circuit...

And again, I see the one capacitor across what looks to be the output power and ground lines....ONE capacitor. Are there any more around there? A small cap across Vdd/Vss on the PIC? Another one across Vin/Gnd on the 7805, one across Vout/Gnd on the 7805, one on the main power input? Maybe even one across V+ and Gnd for the servo?
You need more than one capacitor in a circuit for good performance...One somewhere in the circuit isn't good enough.
http://en.wikipedia.org/wiki/Decoupling_capacitor
http://www.repairfaq.org/sam/aapsfaq.htm

I think there are two possibilities about my problem
power problem or broken servo...

Well, you can waste your time by swapping servo's, trying different code, and so on...or you can get a better power supply and start making progress on your project. Your choice...

[Macgman2000]

I hope my explanation is helpful, it may be more than you are looking for but it is good to know why things are as they are.

The servo's you are using is standard size, under light load they draw about 150 mA. If you hang a 6kg weight on a cable and attach it to the servo horn (about 1cm radius) then you are drawing about 500~800 mA. Since in your setup you don't quite have that much weight, what you have is an extended mass, because of inertia the mass will resist moving at the speed that the servo circuitry is setup for. So the servo struggles to draw more current to compensate. This slowing down and speeding up causes current surges and voltage drops. That is why you see the oscillation.

The hobby servos are rated for 4.8v to 6v (grandfathered since NiCd 1.2v/cell). At 6v it will move faster than at 4.8v (0.20s/60 deg compared to 0.16s/60deg). So seeing a slowing down compared to using higher voltage is to be expected.

What test equipment do you have? Oscilloscope? Multimeter? etc...? What country are you in? is it difficult to get 9v @ 3A for example? If it is difficult then Skimask is correct in using NiMh or NiCd, or maybe even sealed lead acid (alarm system battery usually 3~6A)

Nick

[burak450]

First of all I read everything you wrote.I will go to buy a new power supply (9V 3A or more) and will use more caps as soon as possible...I havent got Oscilloscope,i have only a multimeter...

But tonight I found out a new thing...

I wrote a code to test servo broken or not....

TRISC=0
i var byte
BASLA:

for i=0 to 25
PAUSEUS 19500
pulsout PORTC.2,50

next 
pause 4000

for i=0 to 25
PAUSEUS 19000
pulsout PORTC.2,100

next 
pause 4000

for i=0 to 25
PAUSEUS 18500
pulsout PORTC.2,150

next 
pause 4000

for i=0 to 25
PAUSEUS 18650
pulsout PORTC.2,135

next 
pause 4000

for i=0 to 25
PAUSEUS 18000
pulsout PORTC.2,200

next 
pause 4000


GOTO BASLA
END

I connected first power supply 5.2V 2.5 A without 7805 and saw that...

Servo didnt vibrated at values pulsout 50 and 100 but at 150 and 135 made vibration and finally at 200 didnt make vibration...

Thats its video:http://www.dailymotion.com/burak450/...-52-v-25a_tech

Secondly,I connected power supply 9v 450mA with 7805.Servo came at 50 position and couldnt move 100 and 150 position.I was very very suprised here.After that servo moved 135 position and made vibration!!!!
Finally moved 200 with no vibration!!!

That its video http://www.dailymotion.com/burak450/...with-7805_tech

What do you think gentlemen?

Broken servo or only power problem???