DMX Sequenced Servos - Animatronics Anyone?
I was inspired by the excellent work done by others on these boards using DMX sequencing and various parallax products to interface with them. I decided to take my crack at it using the propeller only with a slightly different spin, pun intended. I decided rather than control lights, why can't I control motors, solenoids, servos, or other kinds of actuators? I spent some time analyzing a free software called vixen which others have pointed out as a great tool. Since all I need are the sequencing signals and I don't really care or want to know about dimming or any other lighting related functionality I ended up writing my own c# plug-in called the SimpleSerial plug-in. It implements what I call the DIY protocol which, for now, gives motor positions for 2 axis (x and y). The position values are in the range of 0 - 255 and they represent the amount of movement past center for that transition. So, for example, if you wanted all the servos to center you would send all 0's (which is the default position). If you wanted to move the x axis completely clockwise you would send out a right movement command with the value of 255. You can use effects in the sequencing software to make the servos perform movements such as wagging and panning. I've posted a youtube video here. I also added an attachment for code. I'm tired and it's very late so I'll try to upload schematic tomorrow but if you have a prop plug then you are halfway there on the RS232. If you have an a RS232/TTL circuit built or know how to build one then you are completely done (If you don't care about the monitor then don't worry about the 2nd RS232 circuit - the software listens on the same pins as the programmer). Just hook up the servos data lines to P0 and P1 with a 4k7 resister in series with each pin. Again, I'll upload schematic in the morning - doing touch and goes on the keyboard now. Enjoy!
*** Update with Schematics ***
Power Supply:
Application Circuit:
Post Edited (soshimo) : 12/23/2008 4:55:27 PM GMT
*** Update with Schematics ***
Power Supply:
Application Circuit:
Post Edited (soshimo) : 12/23/2008 4:55:27 PM GMT
1620 x 1020 - 8K
683 x 341 - 4K
Comments
Will you also be posting the C# code and/or source? If it is an integral part of your project then others may appreciate having that if they wish to re-create the project for their own use.
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Chris Savage
Parallax Engineering
@Cole - absolutely you could easily adapt the plug-in to use for your own light controller if you have one. Say, for example, you have an application already built that drives lights from a prop or bs, it would be very easy to write a simple protocol to get what you need done. There is only one function in the Simple_Serial object that you need to change in that case - it's the Event function which is fired each time a sequence event occurs. If you aren't comfortable with C# I can help you out as long as you define the protocol the way you want it. At any rate, the SimpleSerial Plug-In allows for an easily changeable rs232 interface. Good luck and let me know if you have any questions or need any clarification.
Post Edited (soshimo) : 12/23/2008 3:45:25 AM GMT
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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto for SunSPOT, BitScope
www.tdswieter.com
Good job!
Just a suggestion... You can get around the 0.6V diode drop on J2 if you add a 4th diode on the 5V regulators GND terminal.· Otherwise you'll only get about 4.4V under a load.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
@Beau - Thanks again for another valuable tip! I had worried about that .6v drop across the diode and I forgot about that trick of biasing the ground on the regulator. Your feedback has been invaluable on this PS so I have to credit you with the design!