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Advice on building a circuit from an IR receiver to a modified mouse.

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avz10

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I am busy converting an 8mm projector to capture single frames. I have started with this project, but am now stuck. I use a Eumig 610D projector.



The design of the system incorporates the facility for single frame capture using a computer and appropriate software (cinecap). The software receives an on / off signal every time a frame of film is in the gate. (Using a camcorder to capture the images via firewire). This is sent to the software by a modified mouse via usb and Cinecap forms an AVI file.


As the film is transported through the projector at 3 frames per second it causes the tensioner to trigger a microswitch.


This signal is passed to the microswitch in the modified mouse which in turn tells 'cinecap' to capture a frame of film.

The weakest part of the system is the microswitch triggered by the film tensioner of the projector. The micro switch does not always trigger, so I lose frames. Otherwise everything works fine.

Someone then suggested to build a circuit using an IR receiver and two resistors.


He then connected this small part to the mouse. He placed the reflective sensor (IR receiver) close to the shutter blades and by painting one of them white and the other two matt black he got a pulse once per frame.

He put the sensor on an L shaped piece of strip board so it can just fit in and used a tie wrap to hold it to a mounting post nearby. The screw on the board is used to protect the detector. He commented that he is not dropping frames.

I need a simple explanation what components I need and an easy diagram how to build the section starting from the IR receiver which will receive the impulse to the mouse which will be triggered..

Thanks for any advice
 

avz10

New Member
Perhaps my explanation is too long and tedious.
I am not into electronics, but will be able to build a small circuit.
I need help to build a circuit between an IR receiver and a modified mouse that will go to the PC via a USB. (The IR resceiver will be triggered by a rotating white blade)
 

avz10

New Member
I have contacted the guy who initially built the circuit. I have seen the article that he used, but it is too confusing for me. his is the reference: RevMaster - A Simple Tachometer
I think he used this circuit.


Now this is the first part of his circuit. Is this mainly for the IR, or what are the other parts?


Or to make my life easier, what are the components used, comparing to the diagram?

Same questions here:


Any advice will help
Thanks!
 

duffy

Well-Known Member
Not too long and tedious! Matter of fact, not long ENOUGH. Does your shutter assembly look like his? Going directly off that white-painted shutter arm like he did sure looks like a winner. The tensioner approach seems a little dicey. Get a shot of your shutter assembly, I've used a lot of opto's and may be able to suggest a good one depending on what's in there.
 

avz10

New Member
I posted the same post that I posted yesterday (18 April) on another electronics website. This is what a guy answered:

First, some of what you have posted does not seem to be related to what you want to do. Specifically, the schematic you posted is for a tachometer. It uses reflected IR to generate pulses that are counted with the microcontroller (16F84) and displayed on an LCD as RPM or some other function, such as cutting speed for a lathe. Your project seems much simpler.

Refer to a redrawn portion from the posted schematic:



The +5V and ground come from the mouse. R1 limits the current to the IR emitting diode (IRED) in the sensor device. As the reflected IR light hits the detector, it allows more current to pass. Voltage drop across R2 increases, and thus the signal goes from +5V (no current through R2) to some much lower value. NB: The part I picked for the schematic is an optocoupler. In your device, the IRED is not pointed directly at the detector, but rather is pointed perpendicular to it, so the detector sees only reflected light. In your picture, the sensor is the rectangular black device with 4 pins.

The rest of the schematic you posted is not related to your project. I believe the mouse modification you show in your earlier post simply takes that "low" signal and treats is as a "click", i.e., switch closure, for one of the mouse buttons. At least, that's what the picture of the modified mouse PCB looks like has been done. You may need some interfacing, but it may also just work as is. You also show a small interface box. It is hard to know what is in it from the picture.

The "mouse click" from the optical sensor then keys the camera via a program in your PC. R2 is probably a fairly high value, maybe 1K to 10K ohms. R1 is probably just 100 to 200 ohm. I could not find the part number you reference in the source of datasheets I use.
These are some of the photos I took:
Current setup:


Removing light and lens


Removing holder for diffuser (white spot on blade)



Blade in front of gate


I suppose it will not work to mount an IR detector here, as the light will always be shining.

Backside open. Photo taken from the front


Backside. Front to the left


Edge of blade visible. Taken from below


View from front (chalk on blade)




Cover over blade- marked with X


Cover removed Taken from front:




Hope this help.
Perhaps you can see the other guy's project in perspective


Thanks
Albie
 

duffy

Well-Known Member
Your friend on the other board is right, you only need the upper-right part of that schematic. The inside seems to be identical to the other guy's, may as well follow his technique.
 

avz10

New Member
Thanks Duffy
Do you mean the upper left side of the schematic?

Then it means that R1 is 270k and R2 is 10k?

Does it also means that this diagram

is equal to this?



What is that Q1?

You would not be able to draw a simple figure of how it should look?

I need to apologise for my total ignorance.

Thanks!!
 
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duffy

Well-Known Member
R1 is 270 ohms, not kilo-ohms. Upper left, yes. "Q1" looks like a an Omron EE-SY125 -
Digi-Key - OR557-ND (Omron Electronics Inc-ECB Div - EE-SY125)
- but the notch is on the wrong side. Looks like he might have used a bottom-view style and flipped it over. Check the spec sheet on that page for the pinout, hook it up like the diagram with the resistors. Have you identified the +5V, ground and signal point in your mouse?
 

avz10

New Member
From the initial article, it looks as if the Q1 is a Maplin SY-CR102 Reflective IR sensor.

No, I still need to identify those on my mouse.
 

duffy

Well-Known Member
Maplin's a distributor - if you can lay your hands on those optos, more power to you. I couldn't find them.

Power supply and Ground are easy enough to identify in the mouse: thicker traces, probably a helpful electrolytic or tantalum cap working as a filter across +5V and gnd with a handy polarity mark telling us which is which.

The signal line will be a switch contact, of course. On the switch you want (left, I would assume) it will be the contact with the resistor that leads straight back to the chip on the mouse board. The other switch contact will probably be a ground connection, and common to all the switches, and to Mr. Handy Helpful Power Supply Filter Capacitor.
 

avz10

New Member
Just to see if I am heading the right direction:



If I connect my multimeter to the mouse with the black cable connected to "E" and the red cable to "F" and the reading is +3.3 Volt, does it mean that E is the signal or F is the signal? Does this mean that E is 0 Volt and F is the signal?

My next question is about finding a 5 Volt spot. "A" is connected to the red mouse cable and from what I have read is 5 Volt (??)

And then some help with the Photo reflector. What would be similar products that I can try and found in South Africa?

Thanks for any advice
 

duffy

Well-Known Member
Not sure what's available in S. Africa, but what you are looking for is a "vertical reflective type opto sensor with transistor output". Also, remember that Digikey and others ship around the world.

Tough to tell from that picture what's what. See that huge area of copper on the right? That's probably the ground. If F connects to that, you're good. The other one on that switch will be the signal.

Really need a picture of the top of that mouse board. Red is usually +, but not always. There is almost always a cylindrical electrolytic capacitor across the + and - (ground) power supply lines, and the negative side will be clearly marked. This is the power supply filter cap I was referring to earlier. Look for that thing, it's a good marker for the power supply, and there won't be one across the mouse data lines.
 

avz10

New Member
Sorry that I'm only replying now, but I was away for the week.

Here are some photos. Let me know if you need more detail. (Please be very specific/clear, I'm very new to this!!)







Thanks for any advice
 

duffy

Well-Known Member
Yeah, red's actually (-) on this. White is (+). C4 is that cylindrical electrolytic capacitor I was talking about. See that stripe on the right of it with the "-" symbol? That's the negative. C7 and that other one are also filter caps on the regulated supply for the imaging chip (probably 3.6V).

And, according to that, you have signal and ground backwards on those two black wires. "E" is actually ground.

You probably want to take that 10K pullup out of the circuit completely. The Elan mouse chip uses a current source for those switches (around 50µa), and that +5V bias from your 10k resistor looks like it will do more harm than good.
 

avz10

New Member
Hi Duffy

Thanks for your reply

I also got this from another guy- can you check if you agree:


I can get hold of this sensor in South Africa:



Website
Optek | Optoelectronics and Displays | Optoelectronics | Reflective Optical Sensor | Slotted Optical Switches & Reflective Sensors

So, to summarise:
I have a 5 Volt point
My signal is "F" as in the previous post
Ground goes nowhere
and I need a 270 Ohm and 10 KOhm resistor.

Is this right?

From the specs, can you make out to what pins in the sensor the wires should go?

Thanks
Albie
 

duffy

Well-Known Member
No, ground goes to 0V. You probably don't want the 10k resistor - won't hurt to leave it in, but if it isn't working take it out.

I agree with those markings.

Get that opto, look at the picture of the bottom of the part (the beveled edge indicates orientation), the numbers correspond to the schematic, follow that with your schematic - pins 4 & 2 are ground (0V), pin 1 is signal, pin 3 goes to the 270 ohm resistor.
 

avz10

New Member
Reuben in the Videohelp forum gave this advice:
"I've been looking further at the Optek OPB608A. You can get a more up to date spec sheet for it here http://www.electro-tech-online.com/custompdfs/2009/05/OPB608PDF.pdf. As you found earlier the input from your mouse switch is normally at 3.3 V, the spec sheet for your mouse controller confirms this http://www.electro-tech-online.com/custompdfs/2009/05/eKM8065.pdf. Because of this I think it is safer if the transistor part of the detector uses 3.3 V, while the LED part carries on with 5 V. Again there is an empty hole on your mouse where you can pick up the 3.3 V. "

This was his advice, what I did:


I started to build this afternoon, but might have burnt the IR receptor, as I do not get any signal when I wave white paper/use a fluorescent tube, switch the light of the room on and off, etc.
I do get readings at the different points. I'm not sure if I did anything wrong. (The IR receiver is very cheap and I can easily buy another one)

See what values I'm getting:



Did I overheat the IR receptor with the soldering, or did I do something wrong?

(Other site: Having Trouble with DIY Telecine (8mm) System - VideoHelp.com

Thanks

Albie
 

duffy

Well-Known Member
I suggested you get rid of that 10K resistor - but you made it lower. Who told you to make it 6k? That's just making the situation worse. Remove it completely. The only thing connected to your pin 1 should be that switch line from the mouse.

Shine a flashlight (old fashioned incandescent bulb type, not LED) at the IR receiver and see if that 3.4V on pin 1 drops close to 0V and triggers the mouse switch. If THAT doesn't do it, there may be some other problem.
 
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