damn opto endstop

I don't get it... I have already bought 6 opto endstop, and i didn't managed to make any of them work. I have replaced them with conventional and simple contact switch.

Hmmm, all mine work.

Your saying the that the indicator led is also not working, or you just can't see them in the software?

on the first 3, the indicator led was allways on... On the last 3, the indicator led was allways off... we even bought 3 new sensors to try to find the problem. the solution was found only with the contact switch...

pctr Wrote:
-------------------------------------------------------
> on the first 3, the indicator led was allways
> on... On the last 3, the indicator led was allways
> off... we even bought 3 new sensors to try to find
> the problem. the solution was found only with the
> contact switch...

I have the same problem with my opto switches. None of the 6 works. Could you tell me what type of switch you used and how you wired them to the stepper boards?

Hmmm, all six of my opto stops work perfectly.

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Yep I have 12 fully working opto end stops.
They are very simple circuits so should be relativly simple to test.

Simple test to see if the emiter half of the device is working.

Apply power the opto end stop to be tested now take any kind of digital camera or video camera or mobile [Cell] with a camera look at the emiter end of the device the little V slit in the plastic of the inner face using an electronic camera you will see a bright light if it is working [transmiting infrared light] to check your camera point your TV or Hifi remote at your camera holding a key down. Cool trick..

Ok if its not alight its either wired incorectly at the RJ45 connector or the series drive resistor is the wrong value this should be redredbrown or 220 Ohms.

As the device is a diode even if you have had it wired incorectly once connected corectly it should work.

The only case where the IR led will not work would be if the resistor is less than 220 ohms or short circuit then it could have been cooked or the connection to the diode is shorted sulution remove the short.

By now you should have 50% of the device working.

Now find some material like a thin picee of tin or cardboard to block the IR beam check with the camera to be sure you have blocked the light.

On the new opto isolator boards there is a led that will indicate the gap has been blocked. If this led fails to light.

It could be several problems.

1/. The indicator led is in backwards they only work one way round if its in the wrong way round take it out and turn it arround.

2/. The Led is shorted out with solder remove extra solder between led pins.

3/. Like the infrared led on the sensor the indicator led has a series resistor this needs to be the correct value and not shorted out.

4/. One of the three pins on the opto sensor is shorted to one of the other pins.
remove the short.

5/. Check that the RJ45 connection has not got any shorts on the board. Remove any shorts

In theory by now the device should be working test it using the Aurdrino to read the state of the output pin.

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Bodge It [reprap.org]
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BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

it might not be a bad idea to check your cable. I cant tell you how many times I've changed out a component only to find out in the end it was a bad cable.

I think I saw a another post that might have suggested that a short cable was a patch cable with wiring that was reversed which might have burnt out the units during testing.

A normal straight though cable probally would have worked.

Another reason for not working that also appeared in a previous post is that if your work area is lit with a light that gives off a lot of IR, e.g. halogen bulbs, and you break the beam with something opaque but reflective, the receiver will see the ambient light and not turn off.

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[www.hydraraptor.blogspot.com]

Aside from direct sun light using an electronic camera pointed at any electronics that is near by should show any other IR source.

The Sensors will be made of a material with similar properties to the ICI 962 perspex. This is a special black perspex that effectively filters out all other light except the required IR. I used vacum formed 962 for high resolution IR touch screens around 1980-1984 1024 x 976 using a 64180 processor to perform two simultaneous equations on the averaged shadows of the all the IR beams from both axis using wide angle IR transmiters and recivers on 9" 14" and 21" monitors.
By using this method of calculation, a two finger interlock touch control was possible and used by the CEGB and other customers.

Edited 1 time(s). Last edit at 06/28/2009 04:10AM by BodgeIt.

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Bodge It [reprap.org]
=======================================

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BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]