|
|
|
|
|
| |
Posted by Daniel Kalny on November 6, 2006, 3:03 am
Please log in for more thread options
Hello,
is there anybody who tried to construct encoders with QRD1114
reflective IR sensor? What is your experience? Is this component
suitable for encoders with segments cca 4 mm wide at the perimeter of
an encoder wheel (having diameter of 16 mm)? Thanks for any advice.
Daniel
|
|
Posted by Jon Hylands on November 6, 2006, 9:50 am
Please log in for more thread options
wrote:
> Hello,
> is there anybody who tried to construct encoders with QRD1114
> reflective IR sensor? What is your experience? Is this component
> suitable for encoders with segments cca 4 mm wide at the perimeter of
> an encoder wheel (having diameter of 16 mm)? Thanks for any advice.
Hi Daniel,
I've used the QRD1114 for this, as detailed on my page:
http://www.huv.com/roboMagellan
Specifically:
"For anyone wondering about the wheel encoders, it turns out if you use a
6.8K pullup resistor on a QRD1114 sensor, it produces what amounts to a
digital signal (about 0.15 volts for white, 4.95 volts for black)."
It seems to work quite well. My encoder wheels are somewhat more coarse
than yours (the encoder band is about 13 mm wide), but I did it that way
more to make the code simpler (I was sampling the 2 digital I/O lines on my
PIC, which was also busy doing a lot of other stuff). If you had it hooked
to an interrupt line (or you can poll a lot faster than I could), you
should be okay.
Later,
Jon
--------------------------------------------------------------
Jon Hylands Jon@huv.com http://www.huv.com/jon
Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
http://www.huv.com
|
|
Posted by Gordon McComb on November 12, 2006, 5:35 pm
Please log in for more thread options Jon Hylands wrote:
> I've used the QRD1114 for this, as detailed on my page:
>
> http://www.huv.com/roboMagellan
Slightly off-topic to this...
What was the reasoning behing using the pair of ultrasonic sensors? Was
it to broaden the beam a little more? Given both are on the same pan
mechanism, would that do anything that a slight shift in the horizontal
axis wouldn't do?
Just curious.
-- Gordon
|
|
Posted by Jon Hylands on November 12, 2006, 9:22 pm
Please log in for more thread options On Sun, 12 Nov 2006 14:35:14 -0800, Gordon McComb
> What was the reasoning behing using the pair of ultrasonic sensors? Was
> it to broaden the beam a little more? Given both are on the same pan
> mechanism, would that do anything that a slight shift in the horizontal
> axis wouldn't do?
All of my mini-sumos have two range-finder sensors on the front, mounted
side by side like this. It allows me to, in one time slice, see if the
thing I am sensing is directly in front, or off to one side. Theoretically,
you could figure out the same information with just one sensor, but it
would take a lot longer.
The other thing two sensors gets you, if they are offset and angled
correctly, is the ability to fake a pencil-beam sensor. Basically, you only
pay attention to stuff that shows up in both sensors, and you know when it
does that it has to be pretty much straight in front.
Later,
Jon
--------------------------------------------------------------
Jon Hylands Jon@huv.com http://www.huv.com/jon
Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
http://www.huv.com
|
|
Posted by Gordon McComb on November 14, 2006, 5:33 pm
Please log in for more thread options Jon Hylands wrote:
> The other thing two sensors gets you, if they are offset and angled
> correctly, is the ability to fake a pencil-beam sensor. Basically, you only
> pay attention to stuff that shows up in both sensors, and you know when it
> does that it has to be pretty much straight in front.
Aha! This makes a lot of sense. Thanks for the details.
-- Gordon
|
| Similar Threads | Posted | | Slowing down quadrature encoders | October 21, 2005, 10:47 am |
| Robot kit that includes wheel encoders? | October 4, 2006, 7:04 pm |
| steppers and DC motors as cheapo encoders ? | April 4, 2008, 6:26 pm |
| High resolution, low cost, quadrature encoders | August 30, 2005, 9:28 am |
|
|
|
XML site map
> is there anybody who tried to construct encoders with QRD1114
> reflective IR sensor? What is your experience? Is this component
> suitable for encoders with segments cca 4 mm wide at the perimeter of
> an encoder wheel (having diameter of 16 mm)? Thanks for any advice.