Question regarding Toddler / BOE Servos

TTKoshi · 2006-09-19 21:00

Ok, so I picked up a BOE-Bot last week, and I've been experimenting with it. I know that when I do a PULSOUT 750 command to a "Parallax Standard Servo", the motor stops moving, as it should. Now, looking through the Toddler manual online, I found this little snippet of code:

' -----[noparse][[/noparse] Title ]-----------------------------------------------------------
' Toddler Program 1.1 - Servo Centering.bs2
' Electrically center Toddler servos during robot construction
' {$STAMP BS2}
' {$PBASIC 2.5}
' -----[noparse][[/noparse] Declarations ]----------------------------------------------------
TiltServo CON 13 ' Tilting servo on P13
StrideServo CON 12 ' Stride servo on P12
' -----[noparse][[/noparse] Main Routine ]----------------------------------------------------
Center: ' Center servos with 1500 us pulses
PULSOUT TiltServo, 750
PULSOUT StrideServo, 750
PAUSE 25 ' Wait 25 ms
GOTO Center ' Repeat

So, according to this, sending a PULSOUT of 750 to a toddler motor will center it. Does this mean that unlike the motors from the BOE-Bot, the motors in the Toddler have a "Center" position that is set electronically, that can be called up any time with PULSOUT 750? And is this something that is unique to the Toddler servos? The only reason I ask is because I'm curious to do a walker with the motors I have from the BOE-Bot, and wanted to know if there's a centering option for me using the standard servos. Any help would be appreciated, and hopefully translated into "idiotese", since I'm still fairly new to all of this.

Second follow-up question-
I just realized that the servos for the BOE-Bot are the continuous rotation servos, and the ones in the Toddler are the Mini Servos. Now, I have 2 continuous rotation servos from my BOE-Bot, and I also have a Standard Servo from a BOE-Discovery kit. I noticed that the Standard Servo is like the one above, with Pulseout 750 centering it, but that the 3-pin connecting end has a little plastic flange preventing me from plugging it into my BOE. Can I remove this flange, or is it there to prevent me from using the servo with the board and burning something out?

Many thanks!

-Tom

Post Edited (TTKoshi) : 9/19/2006 9:23:16 PM GMT

Mike Green · 2006-09-19 21:17

The program you've shown should center a standard servo. During construction, you would like to have the servo centered so that you can adjust linkages, mounting screws, etc. The BOE-BOT has continuous motion servos. These don't have a center position. They should stop with a 1.5ms pulse and there's an adjustment in the servo to get it to stop with this pulse width. You can use the same program to adjust the continuous motion servos. Standard servos don't have an electrical adjustment since you can mount the servo (and the "horn" for the linkage) to mechanically adjust for the center position.

allanlane5 · 2006-09-19 21:31

Yes, you should be able to remove the little 'flange'. Just make sure you don't plug it in 'backwards'.

bulkhead · 2006-09-20 03:14

If you don't want to remove the flange, you can plug it into the breadboard and wire it to the center power (not the stamp-regulated one), ground, and a signal pin, but it wont be controlled by switch position 2 (it will turn on with switch 1).

I found the easiest way to remove this flange is to sand it off because if you cut it off you'll need to stand it anyways.

Question regarding Toddler / BOE Servos

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