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November 10, 2007
EdgeChem Jamaica LTD
University of Technology Jamaica
News - December Caption Contest |
about 3 months ago
Yep! we did say cross-platform.
Product ROB-10333 |
about 6 months ago
I have recently bought one of these motors and had some issues using it. Currently i am working with the EiBotBoard but based on the fundamentals all projects should be adaptable to it’s characteristics.
Its a funny motor, great but real funny.
As with any servo, the default position is at zero (used with hesitation). with a swing of 90 degrees to the left or right.
Now this is the important part, as we all already know you cant get an actual 180 degree of movement from this puppy so you will have to settle for the 162 degrees it can produce.
its only capable of a 81 degree swing clockwise or counterclockwise from the default 0 degree position.
If you try to get more than that it will start acting up, as many persons here have described, i.e. the shaft just keep swing from left to right like a mad cat, reason is that the controller inside doesn’t know know the limitations of the motor so when you give a degree turn it cant achieve it goes mad trying to find it (it never will).
If that happens, just issue a command telling the motor to go to a known position (-81 to +81) and it will calm down and regain its sanity.
In terms of using this motor with the EiBotBoard
My hats off to its creator, a great job but sparkfun needs to examine the documentation that comes with the product as most of it is incorrect (by far), especially the servo (S2) command.
the S2 command uses a resolution of 1/12,000,000 of a second to a single unit, works out to be 83.something uS.
This is fine, but the documentation states that the max value for duration is 32,000 which equals to 3 mS.
Simple math tells you this is incorrect as 83uS * 32,000 = 2.66 mS.
So here is how it works…tested and proven….
to have a servo go to the default (0 and in some cases 90 (for the people who prefer that)) you issue the SC command with a duration value of 15000.
each degree is a factor of 111, so if zero is the default position the 6000 = -81 degrees and 24000 = +81 degrees.
My calculations have proven to be spot on (for my application) but i do not know what your project is like so it may vary.
Let me know now it works.
News - Your June Caption Contest |
about 10 months ago
Lilli-Raptor, Size doesn’t matter.
News - According to Pete - Spect… |
about 10 months ago
Not sure if this was already posted already (A lot to read). Maybe looking at an interface of some kind where the user may apply it to a curved surface.
If what you are holding in hand is to be used in the design then it depends on what that soic-8 can do.
Am thinking a touch controller that reports to a master via i2c or spi. The coin cells can power the entire system (if it does not have any power hungry parts).
The problem is that we do not know what the (round looking part) is.
Another idea could be a control system for (anything) that can be fixed to the inside of a cap (hat).
As i said it depends.
I we can suggest an actual design then one could look at small data terminal (something to get people interested in doing more than just buttons and switched)., one that has a sort of hinge.
you could use one of the displays that you sell and make the keypad from a pcb similar to the simon, or even they could make a flex keypad that can be placed on a plastic surface (the inner side of the clam shell.
Something entry level (no need to be complex-ed) but something that does a bit more than the occasional arduino.
You could even power it by a Pi so you get some real punch out of it and maybe use one of the psp lcd’s
(Can the flex wires handle that high bandwidth?)
Maybe you could use a mall breakout board on top of the section that connects to the LCD so you dont have to do any fine pith soldering on it and the actual spots on the flex could be say (2mm apart each). something like that.
News - A Good Ol' Fashioned Capt… |
about 2 years ago
I wonder if we can open a store on Asgard……thinking……
News - What is it you say you do… |
about 3 years ago
Its not simple, but i’ve done it a few times.
For the most part my speech is somewhat like this, “
For newbies and young engineers, especially students it will be hard to know all you need and navigate your way around datasheets and complexed engineering designs.
For some parts, jacking on the wires and turning up the voltage wont work, even though these values are correct.
To get the information you need, the skills you need (tutorials), the tools you need, go to SparkFun.
They’ll Get you started.
And when you have designed your first prototype, go to BatchPCB.
They’ll get you started.
* The best thing since sliced bread (For us beginners, seriously, you are!)”
No public wish lists :(