Here is the part of the schematic that sequences one motor. After several attempts converting the schematic to an image (curse you, demo version!) and printing to virtual printers (who calls something an 'image writer' when it only works for text?) I finally hit the print screen button that few people know what it does, and cropped it in word. Also, if your robot (which is quite cool, I must add) is having jitter problems, use counter weights or springs. My useless machine has a spring to keep a servo from hurting itself driving too far, a spring for keeping the side door shut, and a spring to hold up the arm while the servo is not driving. It even reduced power consumption. You can also bend springs if you have pliers to the exact shape you need and they still work. I would also recommend reading the writing in the schematic before anyone attempts to build it. [attachment=0]
Isn't it possible to make your own pure H2SO4? You can get the hydrogen and oxygen in a large enough quantity if you pass a lot of current through water (I would think about a kilowatt, but you can use much less power for a longer amount of time). Then you get some sulfur, hydrogen, and oxygen in the correct ratios, ignite it, then you should have H2SO4 vapor. I am not entirely sure if this would work, but after reading it I am positive nobody should try it.
I know what you mean. I rarely use microcontrollers on projects. Come to think of it, I never have. I will have a schematic of just controlling one servo. would you like one for controlling multiple servos as well?
Thank you. I guess I kind of left out some very important information. I currently do not have a schematic, as I made this circuit on a wire wrap board with no planning because my breadboards were all taken up, but I can make one if you would like. I did use four servos, and a 555 circuit, which is the only part of the circuit that I got from online, because my original circuit did not work, but that was because of a wiring error, which I later proved because my design worked on a breadboard. I just used a 74hc4514 to switch power (through diodes) to resistors. The resistors are connected to the 555 circuit, and their value determines the position of the servo. The circuitry to sequence through the resistors is made of a 555 and a '161. This allows me 16 sequences, of which thirteen I used. To control which servo drives, I have 4x '151 multiplexers selecting data from four eight bit dipswitches. This is then fed into a '138 demux with the enable tied to the servo control output. One very important detail is that since I have the resistors driven through a diode, I have the 4514 that drives it at 5.6v, the rest of the circuitry is at 5v. I just used a diode to drop 5.6 to 5v. It will not work properly without the voltage difference. The attatched file is the servo control circuit, but the values I used are different. I will do some reverse engineering and create a complete schematic. [attachment=0]
I love seeing analog things done with digital chips. If I understand correctly, it should be very easy to amplify beyond this stage because it is a digital output? Interesting swaying components in the video, too.
I fine tuned the resistors, fixed it up, and made it work every time. And now, its USB powered! I actually grabbed a small 5v supply from my box of wall warts, and apparently it turned out to be a 110v to USB converter with a cord stuck in it. The cord comes from the most useless possible spot (on accident again, I thought the back went on the other way) but decided not to fix it because it just makes it even more useless. Nothing like a convenient one foot cord. And ping pong balls are very flammable. [attachment=1] [attachment=0]
Well, college is in four years, so that lets me use 36.25 motors per year so I do not have to leave any behind. By the way, whenever you get the chance, put 30v through a cd motor. The coils handle it, the bushings can't. :-) Back on topic, I will fix up the resistor values and complete the case after the competition is over.
Thanks. And I wish you didn't say that, because now I have to make some extremely over complicated thing next year. Maybe I will put my pile of 145 motors (I counted) to good use. 1:^)
This is a last minute (and very useless) entry. I wanted to make something that shut itself off, but I wanted it to be different than all of the other useless machines out there. I also wanted it to be fairly complicated for this contest. The result is an arcade shaped device that has one of those switches that your fan or grandmother's lamp might have, with an arm, gripper, and two doors to conceal the arm. There is a total of four servos controlled by eleven 74xx chips on a wire-wrap board. The servos are controlled by a 555 timer circuit, a decoder, diodes, and four dip switches. The dip switches select which servo is driven, and a resistor is switched into the circuit. A '161 controls the decoder, giving sixteen possible sequences, of which thirteen I used. I did not actually use the grandma-style switch, just the chain that I attached to a lever and a spring and used optical switches to trigger the circuit, because they take far more torque to switch than my servos could supply. The case is made of hardboard, and has a bunch of screws that were actually from plastic things I 'recycled'. Some sides of the case are off to see the insides. I did not prototype the wire-wrap board to save time, and I also have not fine tuned the resistor values so it currently likes to clunk into itself. Now it's off to clean my desk, which you can also see in the video. http://www.youtube.com/watch?v=TG-n48N2 ... tube_gdata [attachment=0][attachment=1]
