servo motor resets 16f877a

[mackrackit]

The lower the voltage the slower the motor.

Are the values displayed on the LCD what you expect, are they in range?

[Macgman2000]

Most hobby servo's have a max voltage of 6v. The 450 mA should be OK for testing the servo unloaded.

If you have it turning a platform with large weight/mass then you can easily exceed 1A. A rule of thumb, the closer you get to maxing out the capabilities of your power supply the more noise you will see, especially true with motors, which could lead to glitches. I usually don't go over 50%, if I use a 2A supply for example, I only pull 1A.

Also, decoupling caps are a MUST! use inductors when feeding motors power with custom H-bridges. Use 0.1uf caps to filter out high frequency spikes at the motor and on your power supply to the PIC.

Do a search online for good engineering practice guides for dealing with inductive loads. There are tons of things that will go wrong working with inductive loads, you can solve most of them with well placed caps and careful layout.

Nick

[burak450]

The lower the voltage the slower the motor.

Are the values displayed on the LCD what you expect, are they in range?

Yes,I think,they are....

I follow t and j values by using lcd...

[skimask]

The lower the voltage the slower the motor.
Are the values displayed on the LCD what you expect, are they in range?

How many extra loops is he executing between servo updates?

[burak450]

thanks for the code.I am sorry it doesnt work properly..

First I get a error and I fixed code in compiler--------pauseus 20000-((t*10)+(j*10) you forgot a parenthesis

Servo stiil slower than usual mode

When I worked with your code even j values got out of range...Once I saw j as 195...

I might have another power problem like Macgman2000 said or something about code???

You are right above.I have too many extra loops.I am stuck dont know what to do

[skimask]

Servo stiil slower than usual mode

Does it speed up if you disconnect one at a time?
The PIC won't (i.e. shouldn't) care if there's 1, 2, or 3, or more servo's plugged in since it's not reading anything back from them.

[burak450]

Does it speed up if you disconnect one at a time?
The PIC won't (i.e. shouldn't) care if there's 1, 2, or 3, or more servo's plugged in since it's not reading anything back from them.

When I used single servo and used this code.Everything was perfect.Object followed by servo perfecly.(left-right position)

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS  4
DEFINE LCD_LINES 2
DEFINE OSC 4                                                                       
DEFINE ADC_BITS     8       'A/D çevirim sonucu kaç bit olacak
DEFINE ADC_CLOCK  3       'Clock kaynağı (3=rc)
DEFINE ADC_SAMPLEUS 100
SYMBOL F=PORTA.0
SYMBOL G=PORTA.1
alta var byte
usta var byte
altb var byte
ustb var byte
ADCON1=2
TRISA=3
TRISB=0
PORTB=0
TRISC=0
LCDOUT $FE,1 
pause 2000
adcin  0,ALTa
ADCin  1,usta

t var byte
i var byte
T=150

yap:




adcin  0,altb
ADCin  1,ustb






if  ((((usta+10)*100)/(ustb+10)))>130 and (not (t>194)) then 
T=T+15
endif

if (((alta*100)/altb))>130 AND (not (t<51)) then 
T=T-15
endif


gosub motor





  

LCDOUT $fe,2,#usta," ",#ustb," ",#altA," ",#altb
lcdOUT $fe,$C0,#T   

goto yap

motor:
for i=0 to 25
PAUSEUS 20000-(T*10)
PULSOUT PORTC.2,T

next
return

end

second servo and new code =trouble
Now i unplugged a servo ,left-right position servo stiill slower and worked not properly..

Something wrong about codes you and me wrote....

[mackrackit]

Swap servos? What happens?

[skimask]

second servo and new code =trouble
Now i unplugged a servo ,left-right position servo stiill slower and worked not properly..

still slower and worked not properly.
That doesn't tell me much. Is your servo spitting out banana's again? Or is it making breakfast? both of which are not proper actions for a servo...

[Macgman2000]

OK I have got to ask. What are you moving with your servo? As I said in my previous email, 450 mA is fine for testing UNLOADED servos. Possibly 2 servos. If you are using "standard" size servos then 450 mA is just adequate for turning 1 or 2 without a voltage compression under load. Again.....what are you moving with the servo?

Nick