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31  Using Arduino / Project Guidance / Re: arduino uno sleep mode?? on: January 02, 2014, 10:33:34 am
I like this because it is simple:
http://code.google.com/p/narcoleptic/

The microcontroller uses almost no current compared to the supporting circuit.  Turn off the USB chip and LED.  Now you're left with the regulator idle current.
32  Using Arduino / Project Guidance / Re: Forty-two Unos in a row on: January 02, 2014, 10:30:44 am
Only one wire is needed for the entire length.  How about a really slow PWM.  Like count how long the pin is high every 30 seconds.  This would allow 31 values 0-30.  Why limit this to integers?
33  Community / Gigs and Collaborations / Re: looking for experienced code writer for joint work in movie replica creations. on: January 02, 2014, 10:21:41 am
I have written Arduino code to read a script to automate motion for the movie industry.  The same script format can drive multiple servos and cheap steppers at the same time with one microcontroller.  I do not have an easy way to generate the scripts.  If you can understand how to do this, the rest is easy.  A new idea is to use a special servo with feedback to generate the scripts by moving the unit by hand.  This will take some development effort buy maybe this is what you want?
34  Using Arduino / Motors, Mechanics, and Power / Re: Can a DC motor hold up a weight? on: January 02, 2014, 10:11:59 am
A 28byj-48 stepper motor can support a large weight without power because of the 64:1 gearbox.  Look on Ebay it is only $2.  Your challenge is to get enough torque to lift 2kg.  There are 2 methods.  Use 20v to drive a 5v motor.  Leave plenty of time for cooling.  Or use a small shaft as a drum to wind the string.  Have you seen my code to do this?
35  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: January 02, 2014, 09:52:38 am
There must be a problem or misunderstanding in the code.  Off the top of my head I have seen 30RPM.  At 20RPM for example the speed is almost infinitely variable.  Each step can be 800us or 801us.  So you can go 20.02 or 20.04RPM. 

We can conclude that most motors are 4076.xxx and not 4096.
36  Community / Bar Sport / Re: off planet robot wars! on: December 29, 2013, 01:46:17 pm
We are considering it for the entertainment value alone!
37  Community / Bar Sport / Re: 10 Year OLD resistors pack! on: December 29, 2013, 01:44:52 pm
No wait, sticks and Fire!
38  Community / Bar Sport / Re: 10 Year OLD resistors pack! on: December 29, 2013, 01:44:21 pm
When I was a kid...  There was no DTL...  no RTL...  We used lamps and switches!
39  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 29, 2013, 11:38:48 am
Darn, can't find them by Googling.  After 100 rotations of 4096 it should be off by about 180 degrees.  Is this what you're seeing?
40  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 28, 2013, 01:54:13 pm
Has anyone tested the same physical motor size with 16:1 ratio?
41  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 20, 2013, 02:42:57 pm
I don't have the code or the motors handy right now.  I'm away from my Lab.  I did the test almost 2 years ago.  Attach a pointer or stick to the motor.  Simply rotate 4096, then stop for 1 second.  Repeat.  After a few seconds, minutes, certainly hours the pointer will stop at a different place moving around like a clock.  20/4096 is 0.5% which is a lot!  More than 1 degree error for each revolution.  That's how I know mine are/were exactly 4096. 
42  Community / Exhibition / Gallery / Re: Lunar Module on: December 20, 2013, 02:35:16 pm
It's a Space Race to see who will be first!
http://www.popularmechanics.com/science/space/moon-mars/the-lunar-x-prize-heats-up-16278801
43  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 19, 2013, 07:40:45 am
They are ALL 4076?  Sounds like I'm the only one with 4096 motors?  It's a simple code to test them just keep spinning in the same direction stopping every 4096 for an hour.
44  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 18, 2013, 02:57:37 pm
I understand it's for Beginners but...  In your Wiki you didn't mention that it's possible some motor are NOT exactly 2048 steps per revolution.  This could be confusing for some beginners.  Maybe yours are 2048?  I have not seen any information online about how to identify these motors.  Which category are most popular.  Or where to buy them?
45  Using Arduino / Motors, Mechanics, and Power / Re: 28BYJ-48 5-Volt Stepper on: December 18, 2013, 02:41:37 pm
Thanks for including my code and input on these topics:

1) duty cycle within each step while turning
2) different ways to avoid overheating
3) turning off coils when idle with geared motors
4) non-blocking code can execute other tasks at same time
5) measuring torque simply, to avoid faults or detect end of travel
6) ramping to increase speed and stop skipping steps with a large object

Great Wiki and kit Terry!  Still nobody has documented which motors have exactly 2048 steps/revolution, and which have an odd number with a fraction to the right of the decimal point.  Anyone?
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