Maintaining Servo position

Joe Fishback

I am controlling a RC Servo by inputing the RC receiver signal into a BOE with a BS2. The BOE then outputs pulses to the servo. I have everything·working OK. But now I want the Servo to maintain its rotation position if I let the RC signal go back to center (750 pulses). Then if I move the RC transmitter so that the Servo reverses pass center, then it would go in·that direction. Likewise if I let the RC signal go back to center the Servo would maintain it position. What I am controlling is a Robotic arm. Attached is a pBasic program, but it does not do things right. Can anyone
help.

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······ Joe Fishback

-Robots are my friends-

metron9

I think this is what you are looking for?

' {$STAMP BS2}
' {$PBASIC 2.5}

'File name "C:\Robots\Moving Servo Position
'RC INPUT TO RECEIVER AND IF DIRECTION OR ROTATION POSITION IS CHANGED, SERVO WILL MOVE.
' IF UNCHANGED SERVO RETAINS POSITION.


'------Variables-------
reps VAR Word
RCpulse        VAR   Word
ServoPulseLast VAR   Word
ServoPulse     VAR   Word
ServoPulseLast = 750
ServoPulse = 750
tmprcpulse var word


DO

 tmprcpulse=rcpulse  'save last reading

 PULSIN 8,1, RCPulse   'RC receiver pulse is measured by pin 8 and stored as variable "RCPulse"

 DEBUG  DEC RCPulse, CR
 DEBUG  DEC ServoPulseLast,CR

 IF servopulselast>rcpulse THEN servopulslast=servopulslast-1         'move twards RCpulse
 IF servopulselast<rcpulse THEN servopulslast=servopulslast+1        'move twards RC pulse
 PULSOUT 15,servopulslast                                                             'every 20 mS will hold position if servopulslast  doesn't change
 PAUSE 20


LOOP

Maby you are trying to do this: (psudo code)

do
Read RCsignal
If iRCsignal>lastposition then rotate twards rc signal last=last+1
if rcsignal <750 then rotate twards rcsignal last=last-1
hold servo position at lastposition
loop