Servo troubles
Elie
Posts: 6
Hi
I wrote this program to turn a servo in one direction if a relay switch is turned on, and in the other direction if the relay switch is off.· Everything in the code seems to work the way I want it to, but the servo will not turn.· It just jerks left and right every once in a while and ends up staying in the same position.· Does anybody see anything wrong with the servo code?
Thanks for the help,
-Elie
Here is the program, the servo code is in the RotateNeedle subroutine:
' {$STAMP BS2sx}
' {$PBASIC 2.5}
'variable and constant declarations
DEBUG "initializing", CR
INPUT 0
relaySwitch VAR IN0
SwitchOn CON 0
SwitchOff CON 1
ConsumerLED CON 2
HippieLED CON 3
ServoPin CON 15
LOW ServoPin
MinRot CON 475
MaxRot CON 2750
MaxIncr CON 5
MaxDecr CON 2
increment VAR Word
MaxIndex CON 50
index VAR Word
currentRot VAR Word
currentRot = MinRot
'reset the gauge to its·start position
DEBUG "resetting", CR
FOR index = 0 TO MaxIndex
· 'DEBUG ? index
· PULSOUT· ServoPin, currentRot
· PAUSE 20
NEXT
'Main function
' checks if user is consuming and calls the appropriate subroutines
DEBUG "ready", CR
Main:
· DEBUG ? relaySwitch
· IF relaySwitch = SwitchOn THEN
··· LOW consumerLED
··· HIGH hippieLED
··· GOSUB Consume
· ELSE
··· HIGH consumerLED
··· LOW hippieLED
··· GOSUB Relax
· ENDIF
· PAUSE 50
· GOTO Main
'Consume subroutine
' gradually moves the needle towards the·maximum position until the user stops consuming
Consume:
· DEBUG "consuming", CR
· increment = 0
· DO
··· 'DEBUG ? "going up", CR
··· GOSUB IncrementRotation
··· GOSUB RotateNeedle
· LOOP WHILE (relaySwitch = SwitchOn)
· RETURN
'Relax subroutine
' gradually moves the needle towards the·minimum position until the user starts consuming
Relax:
· DEBUG "relaxing", CR
· increment = 0
· DO
··· 'DEBUG ? "going down", CR
··· GOSUB DecrementRotation
··· GOSUB RotateNeedle
· LOOP WHILE (relaySwitch = SwitchOff)
· RETURN
'IncrementRotation subroutine
'· increments the current rotation value of the servo taking into account another variable to slow down the movement
IncrementRotation:
· increment = increment + 1
· IF (increment >= MaxIncr) THEN
··· IF (currentRot <= MaxRot) THEN
····· DEBUG "incrementing rotation angle", CR
····· currentRot = currentRot + 10
··· ENDIF
··· increment = 0
··· DEBUG ? currentRot
· ENDIF
· DEBUG ? increment
· RETURN
'DecrementRotation subroutine
'· decrements the current rotation value of the servo taking into account another variable to slow down movement
DecrementRotation:
· increment = increment + 1
· IF (increment >= MaxDecr) THEN
··· IF (currentRot >= MinRot) THEN
····· DEBUG "decrementing rotation angle", CR
····· currentRot = currentRot - 10
··· ENDIF
··· increment = 0
··· DEBUG ? currentRot
· ENDIF
· DEBUG ? increment
· RETURN
'RotateNeedle subroutine
' rotates the servo to its current rotation angle
RotateNeedle:
· FOR index = 0 TO MaxIndex
··· 'DEBUG ? index
··· PULSOUT ServoPin, currentRot
··· PAUSE 20
· NEXT
· RETURN
I wrote this program to turn a servo in one direction if a relay switch is turned on, and in the other direction if the relay switch is off.· Everything in the code seems to work the way I want it to, but the servo will not turn.· It just jerks left and right every once in a while and ends up staying in the same position.· Does anybody see anything wrong with the servo code?
Thanks for the help,
-Elie
Here is the program, the servo code is in the RotateNeedle subroutine:
' {$STAMP BS2sx}
' {$PBASIC 2.5}
'variable and constant declarations
DEBUG "initializing", CR
INPUT 0
relaySwitch VAR IN0
SwitchOn CON 0
SwitchOff CON 1
ConsumerLED CON 2
HippieLED CON 3
ServoPin CON 15
LOW ServoPin
MinRot CON 475
MaxRot CON 2750
MaxIncr CON 5
MaxDecr CON 2
increment VAR Word
MaxIndex CON 50
index VAR Word
currentRot VAR Word
currentRot = MinRot
'reset the gauge to its·start position
DEBUG "resetting", CR
FOR index = 0 TO MaxIndex
· 'DEBUG ? index
· PULSOUT· ServoPin, currentRot
· PAUSE 20
NEXT
'Main function
' checks if user is consuming and calls the appropriate subroutines
DEBUG "ready", CR
Main:
· DEBUG ? relaySwitch
· IF relaySwitch = SwitchOn THEN
··· LOW consumerLED
··· HIGH hippieLED
··· GOSUB Consume
· ELSE
··· HIGH consumerLED
··· LOW hippieLED
··· GOSUB Relax
· ENDIF
· PAUSE 50
· GOTO Main
'Consume subroutine
' gradually moves the needle towards the·maximum position until the user stops consuming
Consume:
· DEBUG "consuming", CR
· increment = 0
· DO
··· 'DEBUG ? "going up", CR
··· GOSUB IncrementRotation
··· GOSUB RotateNeedle
· LOOP WHILE (relaySwitch = SwitchOn)
· RETURN
'Relax subroutine
' gradually moves the needle towards the·minimum position until the user starts consuming
Relax:
· DEBUG "relaxing", CR
· increment = 0
· DO
··· 'DEBUG ? "going down", CR
··· GOSUB DecrementRotation
··· GOSUB RotateNeedle
· LOOP WHILE (relaySwitch = SwitchOff)
· RETURN
'IncrementRotation subroutine
'· increments the current rotation value of the servo taking into account another variable to slow down the movement
IncrementRotation:
· increment = increment + 1
· IF (increment >= MaxIncr) THEN
··· IF (currentRot <= MaxRot) THEN
····· DEBUG "incrementing rotation angle", CR
····· currentRot = currentRot + 10
··· ENDIF
··· increment = 0
··· DEBUG ? currentRot
· ENDIF
· DEBUG ? increment
· RETURN
'DecrementRotation subroutine
'· decrements the current rotation value of the servo taking into account another variable to slow down movement
DecrementRotation:
· increment = increment + 1
· IF (increment >= MaxDecr) THEN
··· IF (currentRot >= MinRot) THEN
····· DEBUG "decrementing rotation angle", CR
····· currentRot = currentRot - 10
··· ENDIF
··· increment = 0
··· DEBUG ? currentRot
· ENDIF
· DEBUG ? increment
· RETURN
'RotateNeedle subroutine
' rotates the servo to its current rotation angle
RotateNeedle:
· FOR index = 0 TO MaxIndex
··· 'DEBUG ? index
··· PULSOUT ServoPin, currentRot
··· PAUSE 20
· NEXT
· RETURN
Comments
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Sid Weaver
New Combo LCD Backpack
http://hometown.aol.com/newzed/index.html
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Sid Weaver
New Combo LCD Backpack
http://hometown.aol.com/newzed/index.html
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Are you saying that I don't need that loop, I just send a PULSOUT command once?
Every other servo example I saw used a FOR loop and sent the PULSOUT at least 20 times...
pulsout servo, 850
The servo will go to 850 but it will have no holding power.· If you want it to maintin its position under load then you must write
for x = 1 to whatever
pulsout servo, 850
pause 20
next
If you want the servo to move slowly from 750 to 850 then you write:
pout = 750
pstop = 850
runit:
pulsout servo, pout
pause 25
pout = pout + 1
if pout = pstop then do something else
goto runit
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sid Weaver
New Combo LCD Backpack
http://hometown.aol.com/newzed/index.html
·