From: John G. Lussmyer
On Sun, 20 Aug 1995, Matthew Brady wrote:

Perchance has anyone come across any vendors that sell units or plans
for units for multi-channel proportional motion control systems
utilizing standard R/C transmitters for motion sequence programming and
standard R/C receivers & servos for repeatable sequence playback?
Ideally, the recording unit would allow editing, that is, combining of
separately programmed channels. I know, there's a runon sentence
there. Sister Mary Gregory would have given me a black eye for that one!

Have you looked into using the “Basic Stamp”? It is a tiny little computer that is easy to use to control servos. You could write a program to run through a sequence of events, possibly even record a sequence. It is cheap too, depending on model. I have a friend who uses them with servos quite a bit.

From: Lycanthrope (A.K.A Larry)
Hello everyone,
Thought I would break in for a quick offering. While i am not sure who is commercially making systems for recording and playing back movements, I could design, and build them custom if there is interest, and probably for a sight less money. If nothing else I could create the schematics for such a system and post them. If the interest is REALLY there, I could design printed circuit boards, and actually manufacture the devices, though admittedly this is were I would spend the majority of the time and money to create them. Still, i could produce circuits in surface mount, which for the average electronics hobbyist, is a frustration at best. I am guessing that a board capable of controlling 2 servos with 256K of memory (or 128,000 positions of storage per servo) would cost about 40-60 dollars to construct including the cost of a double sided PCB. Such a board could be configured to store multiple selectable programs, and could be modified to take input to select which program ran. Other options are to use micro processor based boards, but there are advantages to using dedicated hardware, especially for ease of programming and use.

Is anyone interested?

From: Joe Dunfee

from Larry Lyle


Thought I would break in for a quick offering. While i am not sure
who is commercially making systems for recording and playing back
movements, I could design, and build them custom if there is interest,
and probably for a sight less money. If nothing else I could create the
schematics for such a system and post them.

I have been thinking about what would be involved in such a system myself. I have seen a few hardware solutions for controlling multiple servomotors (ie. 8 to 16 servos) at relatively low cost. Scott Edwards sells one kit. However, the real problem is software. I have been thinking the best solution would be something that could utilize the vast collection of MIDI sequencing programs would be the easiest. The programs are multi-tracked and have extensive editing capability. Perhaps the note can signify a particular servo motor and the volume of the note the position of the servo.

I am guessing that a board capable of controlling 2 servos with 256K
of memory (or 128,000 positions of storage per servo) would cost about
40-60 dollars to construct including the cost of a double sided PCB.

I think that 2 servos is way too few. The other hardware controllers I have seen can do 8 servos. Also, if you come up with a fully integrated solution, you can and should charge more money.

Such a board could be configured to store multiple selectable programs,
and could be modified to take input to select which program ran.
Other options are to use micro processor based boards, but there are
advantages to using dedicated hardware, especially for ease of
programming and use.

I guess in the context of this discussion group, people would want a portable system that they can carry inside their costume. That would probably rule out carrying a laptop computer with you. So the dedicated hardware would probably be the best choice for this kind of use.

From: Joe Dunfee

On Sun, 20 Aug 1995, Matthew Brady wrote:

Perchance has anyone come across any vendors that sell units or plans
for units for multi-channel proportional motion control systems
utilizing standard R/C transmitters for motion sequence programming
and standard R/C

Have you looked into using the “Basic Stamp”? It is a tiny little
computer that is easy to use to control servos.

The problem with the basic stamp is its extremely small memory size. I am also told that the act of controlling a servo takes up alot of the processing time anyway. I just read the June “Nuts & Volts” magazine, they had an article by a guy who has a special circuit that will control 8 servos and itself accept signals from a serial port. It was $29. However, no recording software. I would hate to spend that kind of time writing software for a hardware product that may not be available in 1 year or so.

By the way, here is the guy who wrote the article. Scott Edwards E-mail 72037.2612@compuserve.com

From: John G. Lussmyer

Have you looked into using the “Basic Stamp”? It is a tiny little
computer that is easy to use to control servos.

The problem with the basic stamp is its extremely small memory size.
I am also told that the act of controlling a servo takes up alot of
the processing time anyway.

I think the basic stamp II gets around those problems. (8x the RAM, and 5x the speed). It is supposedly going to be out Real-Soon-Now. (I have a friend waiting for one….)

From: Lycanthrope
Hello again everyone,
Thought I would add some info to further clarify some aspects of my suggestion of creating circuit boards. I have been doing work with design and construction of circuits/circuit boards for a while and have some experience with what it costs to design/build them. A point to note in my experience is that the cost to build a larger circuit board when the number of boards to be bought is small, does not increase by much with increasing board complexity, as so much of the cost of production is in the initial design and setup cost. If you need a board which handles 8 or 32 servos, the initial cost will not very much over the 2 servo board. Right now i am trying to get a feel for what everyone needs, from this I would like to make a system which is compact, and very flexible such that it can be adapted to most anyones needs, and wont cost you any appendages or siblings. I have seen three things thus far 1) The need for 8 or more servos, 2) the ability to have input for synchronization and/or program access. 3) must be small enough to be warn in a costume. The basic system I have conceived would be programmable from a teach pendant (like a remote control) but could easily be adapted to accept input from a computer.

anyway.. send me more thoughts and suggestions.

From Marcwolf

I have been having a lot of success with a range of chips called PicAXE's. These are supplied from http://www.rev-ed.co.uk/picaxe/ are compaired to a Basic Stamp (I & II) are extremely cost effective.

There is a servo controller board called an SD21 which you can get from here http://www.robotshop.ca/home/suppliers/devantech-en/devantech-sd21-servo-controller.html and with it you can controll 21 servos. With this board its really is a 'set and forget' ad the servos will be continually refershed whislt the calling computer does something else.

You can plug an BasicStamp into the SD21, or a PicAXE 18X chip (worth about $15AUD) and you can program this directly on the SD21 board.

With a little work you can also add additional memory on it for sequencing too. As you are writing the code it is upto you to do what you want.. But as mention most of the servo housekeeping is taken care of for you.

If any of you have watches my tail wagging video http://www.marcwolf.org/picaxe/img/tailwag.wmv this was done using the little 08M prototyping board and about 5 lines of code.

Hope this gets some people thinking on what they can do.. On the cheap also :>