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1066  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: February 01, 2012, 02:16:31 pm
Waiting for BL-5C.  Tried it with friends tiny camera.  First mounted tight against metal frame.  High frequency vibration in video.  Then tried loose rubberband to absorb vibration hanging it between struts.  Now low frequency like 30hz every other frame.  Something is mechanically unbalanced in the toy blades that I hadn't noticed before.  3rd tried soft foam peanut, tried both tight and loose rubberband squeezing it between the frame and camera.  Still vibration in video this time between the 2 other frequencies.  I bet it would work if I hang it by a string!  Allow it to rotate?  Any better ideas?

The problem is the heli is vibrating up and down in space.  I can show this by slowing down the video.  I can attach it in such a way that it cannot rotate the camera quickly.  Moving up and down 1mm on an axis does not change the image of a far away object.  So it must be changing the angle up and down?

At a low frequency about 30hz, and a high frequency near the motor speed.  No matter how I attach the camera...  IT IS TOO LIGHT!  It moves in space with the heli.  This is turning into a difficult mechanical engineering problem.  How do you design a spring or a foam pillow that absorbs the vibration?

I got it so it is just generally blurry inside, without enough light.  I think the light outside might solve the problem.  Depending on the camera it should change the virtual shutter speed?
1067  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 31, 2012, 11:01:42 am
23g is less than 43.  I think this will make a difference in how it flies.  Is this number correct?  Could it be?
If I cut your battery in 1/2 it would weight 22g.  Your price is not so different from $3 x2.
1068  Using Arduino / Programming Questions / Re: Code up for review... any (under)takers? on: January 31, 2012, 10:51:36 am
Can we have a summary of what it does?
1069  Using Arduino / Project Guidance / Re: Voice Scrambler on: January 31, 2012, 10:40:18 am
Certainly you could compress these MSBits of an audio stream like that.  But how about the next bit?  The LSB?  Wouldn't work.
1070  Using Arduino / Motors, Mechanics, and Power / Re: Help Microstepping! on: January 31, 2012, 10:18:54 am
Nice pseudocode Bettersense!
Try my code.  It's good to +-1/22 of a degree using half steps.
I tried microstepping with PWM, who would need 0.0004 degree steps?
0.0004 precision when stopping?
Can you think of an application for this?
Is there a narrow range of speeds where it would be smoother?
Under what mechanical circumstances would this matter?
I'd like to learn and add a feature to my library.
Can we see some example code?
I have seen that with a load, moving slow, with time between steps...
It gets stuck instead of moving 0.0004 degrees.
With less load it "jerks" moving nearly 1/11th of a degree at a time anyway, same as half steps.
Maybe someone might want 0.02 deg steps?
This would make it smoother at one specific speed only compared to half stepping.
I believe this technique is only useful with different hardware than 28BYJ.
Not sure what motor you have...
1071  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 10:35:11 pm
Nokia BL-5C is only $3 on Ebay.  23 grams.  3.7V.  Can't beat it for the price.
It seems to me that Ebay can solve most engineering problems for us!

How can that weight be correct?  I have a bunch of tiny cell phone batteries around the house, and they all weigh at least 100g, most of them 120g.  I guess mine are not Li-ion?  Just looked they are.  How can this one be so light, with the same capacity in mAh?  For $3?  Is it a typo?  Anyone know?  How do they do that?  When none of the other brands are as light?
1072  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 10:19:26 pm
It even works at 3.00V!  Unfortunately that's the loaded voltage of the Saft battery after 5 minutes...
It works IN the helicopter just fine with 1/2 a 9v battery.  I even got it off the ground.  But it's a little bit heavy.
I'm going to search for batteries online...
1073  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 08:01:40 pm
At 5V I get the same results as without the 1/6th 9v battery + 2 ohms.  As soon as I turn on the motor with the stick on the transmitter it's complete snow.  It can't be that sensitive to voltage, or I'd have to retune it every minute as the battery is used.  There's a dial on the video receiver.  No retuning is needed with a 3.7v battery.  Even after hours, without the motor running.  Let me see if it runs on 3.4v.  If so I know what to do!

It runs on 3.3v, no re-tuning of the receiver needed as it goes down from 5v.  So I'm going to use the 3.6v Saft battery.  Then I will try a resistor between them to increase the life of it.  Ideas?
1074  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 06:55:48 pm
At 5.2v the camera does not work!  I've got a strong signal, a black screen.  Turning on the motor does not change the black screen, so that's good news.  0.3v = 150ma x 2 ohms.  Back in a flash!
1075  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 06:14:32 pm
Yes, but 1/3 of the power is wasted in the diodes.
Can't I add 1/6th of a standard 9v battery to the 3.7v battery in the copter in series?
Obviously it would continue to provide power to the motors.
Measuring them under load it should be 5.2v.  Why not?
Let me try it...
1076  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 05:57:48 pm
Is there any alternative to the chip I mentioned?
1/2 of the 7.4v Lipo is 22g?  Can anyone verify this is possible?
The battery in my plane runs for 5 hours powering the camera until I gave up waiting.
1077  Using Arduino / General Electronics / Re: 2.4ghz camera interference help please! on: January 30, 2012, 05:37:39 pm
1/2 a 9v battery is too heavy, even without the metal case.
This is better:
http://www.amazon.com/Saft-LS14250/dp/B002GJSQPO
But it's expensive, not rechargeable, and only 3.6v.
It seems to work at first, but not sure for how long as the voltage goes down.
I want lighter!  It's a small copter.  Do you think the DC-DC will remove the noise?

I can't believe your link weighs 43g.  I can read it says that.  My Saft is 43g.
Must be much more dense, it's tiny.
1/2 9v is 90g.
1078  Using Arduino / Motors, Mechanics, and Power / Re: New 28BYJ-48 library on: January 30, 2012, 04:33:05 pm
http://www.amazon.com/gp/product/B0000AUR21/ref=cm_cr_mts_prod_img
This is much better in the real world with big lenses making a GigaPan, it's sturdy.
I wrote a simple library for it. You just need a screwdriver to modify it.
I removed the internal stops and made a simple one on the outside.
You could design a bearing to use with our tiny motors.
But I just mounted my T2i on the shaft!  Made a wooden base for the motor.
It works fine so long as you have a level table or rock to set it on.
The Bescor goes 7deg/sec max.
Our stepper 30RPM which works out to 180deg/sec or 25x as fast.
Too fast to stop blur with a 200mm lens spinning on it.
That's why I wrote unramp() to stop and start.
With the Bescor I can take a panorama or Gigapan without stopping @300mm.
With the stepper I can capture 360 deg in 2 seconds.
I've been making endless panoramas, they just keep going and going, round and round...
Faster than this, 1/8th the price:
http://gigapan.org/cms/shop/epic-pro
1079  Using Arduino / Motors, Mechanics, and Power / Re: New 28BYJ-48 library on: January 30, 2012, 02:01:32 pm
Finally some feedback!  Thank you.  I tried to make it simple.  The 4 nowait functions might confuse someone.  All the functions are calibrated to be accurate according to RPM.  The torque is inverse to the RPM past the startup speed.  At slow speeds the Hot functions have more torque than the cold ones, especially with a 5v supply.  This is at the expense of power consumption.  Please ask if you want to know why I did something in the code.  Did you try the halt when there's too much load subroutine?  You can change it to print the load instead.  Did you see you can turn 1.00 deg 360x and it works!  Or 1.50 deg 240x.  3.00 deg 30x is 90.  Without microstepping.  You get the picture.

You can easily remove the floats to make the code size much smaller.  You only lose movedeg and err functionality.  Only the functions that you use are included in the executable.  Some of my sketches are 1.2K in size.  I think this will work on ATTINY85 with a few changes.

I was thinking of adding sleep between steps when you're going slow.  Anyone want it?
1080  Using Arduino / Motors, Mechanics, and Power / Re: New 28BYJ-48 library on: January 30, 2012, 01:24:16 pm
Download the zip file (attached above).  It's not a library yet.  Compile the entire file in IDE.  Uncomment one of the lines in loop() to test it with your motor. 
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