Jeff Martin and the Free Energy Quadrature Decoder.

rjo__

Thank you, Jeff Martin, for you free energy quadrature encoder object http://obex.parallax.com/objects/24/. I was about to run out of cogs... and was beginning to wonder if I was ever going to build
my own electric car. Jeff Martin to the rescue... freed up my cogs and restored my faith in my future.

Here's the story ... I was building the worlds cheapest telepresence robot, Zippy http://www.peanutbutter.com/, entirely out of peanut butter lids, 2 falhaber motors, a Chinese bluetooth and a wireless camera that I picked up a one of the unofficial Propeller meetings... total investment (excluding controller) , $16. The motors require two counters each, the serial com 1 cog, and the quad encoders two counters each. Not really a problem, but for my personal vehicle, I'm going to want 4 motors and encoders... hopes wained... until I found Jeff's ancient object, written in the early days.... all the encoders I want... 1 cog.

Hooked everything up... except I forgot the 5V and ground to the encoders... and one of the encoders still worked:) No kidding, swear to God, hope to die if I lie.

That is one hell of an object there Jeff.

Hey guys, what's up with this?

Rich

Jeff Martin

rjo__ wrote: »

Thank you, Jeff Martin, for you free energy quadrature encoder object http://obex.parallax.com/objects/24/.

...

Hooked everything up... except I forgot the 5V and ground to the encoders... and one of the encoders still worked:) No kidding, swear to God, hope to die if I lie.

That is one hell of an object there Jeff.

Hey guys, what's up with this?

Rich

You're welcome Rich! Glad my object helped you.

I certainly didn't design it to be a "free energy" object. It's hard for me to say why one of the encoders worked without power and ground. But to solve that mystery, here's what I'd suggest exploring:

1. Are they both the same kind of encoder? If not, what are the differences between them that might account for the behavior.
2. Are they both wired essentially the same way?
3. Is there any power on the lines that could be supplying just enough to power one encoder and not the other. Some devices will naturally end up working by parasite powering themselves from power that is present on I/O pins.
4. Use an oscilloscope if you can to monitor the power and ground lines as well as the I/O lines of the encoders.

rjo__

Jeff,

Thanks for the response, that is one beautiful object.

1. The two encoders WERE identical. They are part of a Faulhaber geared motor from the Electronic Goldmine (thank you erco). There is now a generic form of it for $3. I have fifteen of them lying around:)
David Cook has a nice write up: http://www.robotroom.com/FaulhaberGearmotor.html. The motor and encoders
are supplied by separate sources and have separate connections. I had the motor power supplied with 7.4v and running full tilt, but the 5v supply for the encoders was not hooked up at all
(no wires present!!!).

2. I hacked one apart, and it appears to be a magnet based sensor... so, I was wondering if a current was being generated by the spinning magnet, with my input pin acting as a drain or maybe there is a short...

3. I don't see how... they weren't hook up:) This was a first for me... usually I hook them up backwards. This time, I just forgot about them altogether.

4. I don't have an oscilloscope... gave it away since I never seemed to need it:) Have my eye on a PropScope for Christmas.

Regards,

Rich