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View Full Version : How to control a servo with BS2p-24?!?



pcrobot
05-20-2005, 11:51 AM
I want to control a servo motor with my BS2p-24 & BS2p-24 Demo Board. I do not see any servo plugs http://forums.parallax.com/images/smilies/cry.gif I don't know how to wire it, like the BOE or maybe the homework board? My demo board doesn't specifically match anything from "What's A MiCon?" book. Please help!
Thanks!

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Robotics
ro-bot-ics (noun)
the science or technology of robots, their design, manufacture, application, use, etc.

Chris Savage
05-20-2005, 12:23 PM
Hello,

ии If you have a 3-pin header, you can connect the Servo through the breadboard.и Just connect the black wire to Vss, the Red wire to Vdd and the White wire to a Stamp pin.и Then, you can use the code from the "What's A Microcontroller?" text, but you must change the pulsout values for the BS2p, as they are different timing from the BS2.и If you don't have the 3-pin header, you may still be able to do it using wires carefully from the Servo plug to the appropriate connections on the Demo Board.




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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

pcrobot
05-20-2005, 08:51 PM
Yeah, I don't have any set apart servo plugs (I do have two columns of 5 pins, but I don't think that's for servos.) http://forums.parallax.com/images/smilies/burger.gif
I can wire it like the Homework board...but that means I need to purchase a 3-pin header...oh well. http://forums.parallax.com/images/smilies/sad.gif
Thanks for your help! http://forums.parallax.com/images/smilies/cool.gif

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Robotics
ro-bot-ics (noun)
the science or technology of robots, their design, manufacture, application, use, etc.

Forrest
05-20-2005, 09:06 PM
Use wires pressed into the servo connector to connect it to the wireless breadboard. If you haven't purchased any hookup wire for your project yet, Radio Shack has a nice hookup wire assortment for $6.29 P/N 276-173

Jon Williams
05-20-2005, 09:54 PM
Yes, I push 22-guage solid wire connections into servo connectors all the time -- this will work for testing.

For the BS2p, the pulsout values for the "standard" servo positions would be:

1.0 ms = 1250 (left)
1.5 ms = 1875 (center)
2.0 ms = 2500 (right)

The values are calculated by taking the servo position (in microseconds) and dividing by 0.8 (the PULSOUT unit for the BS2p).

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Jon Williams
Applications Engineer, Parallax
Dallas, TXи USA

pcrobot
05-20-2005, 10:32 PM
Okay, thanks for the pulsout values! http://forums.parallax.com/images/smilies/wink.gif Now, about that wire… I assume that will replace the 3-pin header, which would be great! Is that box of wires from Radio Shack the correct specs? (Solid, 22-gauge wire?) Thanks for all the help! http://forums.parallax.com/images/smilies/scool.gif

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Robotics
ro-bot-ics (noun)
the science or technology of robots, their design, manufacture, application, use, etc.

Jon Williams
05-20-2005, 10:40 PM
Yes, use solid 22-guage (24 is too small, 20 too big). Be very careful making your signal, Vdd (+5), and Vss (ground) connections to the servo.

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Jon Williams
Applications Engineer, Parallax
Dallas, TXи USA

Forrest
05-20-2005, 10:48 PM
The wire in the Radio Shack kit is the right size for connecting Parallax servo's to the breadboard - I just tried it.

pcrobot
05-20-2005, 10:54 PM
Okay...I was just checking...cool! http://forums.parallax.com/images/smilies/idea.gif
Thanks again! http://forums.parallax.com/images/smilies/roll.gif

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Robotics
ro-bot-ics (noun)
the science or technology of robots, their design, manufacture, application, use, etc.

"Steamboat Ed" Haas
07-21-2005, 03:43 AM
и Speaking of headers I've been trying without any luck to find some of the little "#610 header blocks" that are used on the BS2 to connect servos. I want to solder some of these onto one of the pre-tinned boards, to complete a project that will include several servos. Has anyone got a source? Google turned up zip.

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ииииииииииииииииииииииии Hacking the Trailing Edge!
ииииииииииииииииhttp://www.nmpproducts.com/intro.htm
ииииииииииииииии---Decks a-wash in a sea of words---

Forrest
07-21-2005, 04:28 AM
If you're referring to simple straight male headers with .1 inch spacing, then I've used P/N ACS1428 from www.bgmicro.com - they cost $.33 each (36 pin strip) or 4 for $1. Snap them apart you'll get (48) 3 pin headers for $1 + shipping.