Servo troubles.

[Glenn]

Decrease the 100 until it starts pausing at one end (meaning the PIC is trying to over-drive the servo) and increase the 200 until it starts pausing at the other end (again, meaning the PIC is trying to over-drive the servo in the other direction).

Well, as you said before the values depends on which servo I use, I settled for the servo that I'm going to use (the brand new china-made) and with that 75 and 255 seem to be the correct values, however, when its 255, its still not at the endpioint, its a few mm more left. ..However this doesnt matter.

[skimask]

however, when its 255, its still not at the endpioint, its a few mm more left. ..However this doesnt matter.

Change your BYTE variable to a WORD variable and you'll be able to go beyond 2.55 ms. But that sounds a bit goofy since a 2.55ms pulse width is out of spec for most servo's. But hey, if it works for you, go with it...

[Acetronics2]

Hi, SKI

The maximum I ever reached is 250 µs to 2600 µs ... with a Futaba S3001 or a Robbe RS100 ...

not linear at all between 250 and 600µs !!!

regards
Alain

[Acetronics2]

Hi, Glenn

I Think I've found what looks "strange" to you ...

@ device HS_OSC,MCLR_OFF,LVP_OFF,WDT_ON,PROTECT_OFF
DEFINE OSC 4

CMCON = 7 ' Disable comparators

PORTA = %00000011
PORTB = 0

TRISA = %00000011
TRISB = 0

'Use b1 to hold pulse width variable for servo 1

b1 var WORD

'initialize variables
b1 = 150 << 4

low portb.0		' put the servoport low.
main:

        low portb.0
	pulsout portb.0, ( b1 >> 4 )	'send current servo 1 position out
	if porta.0 = 0 then left1	'check for pressed switch 0
	if porta.1 = 0 then right1	'check for pressed switch 1

bugtrap:

        if b1 > ( 150 << 4 ) then
               b1 = b1 - 1

        else
               if b1 < ( 150 << 4 ) then b1 = b1 + 1
              
        endif
        pause 18 : goto main

left1: 
         IF porta.1 = 0 Then bugtrap
         b1 = b1 + 1 
         if b1 > ( 3199 ) then max1
         Pause 8 : goto main

right1:  
           IF Porta.0 = 0 Then bugtrap
           b1 = b1 - 1 
           if b1 < ( 1601 ) then min1
           Pause 8 : goto main

max1:  b1 = ( 100 << 4 ) : goto main ; jump to other side

min1:  b1 = ( 200 << 4 ) : goto main ; jump to other side

END

This is not the "perfect movement" ... but the maximum to get from this coding style.

Alain

PS : Question : Why multiply b1 per 16 ( << 4 ) and divide it per 16 ( >> 4 ) when outputting the pulse.
The answer to last trouble is here !!!