Simple question OptoCoupler

Post here to discuss the 8x85 RGB LED POV Display.

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GedasK
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Simple question OptoCoupler

Post by GedasK » Thu Mar 10, 2011 8:23 pm

Hello, all. :) I have simple question, Brad creat "32X64 PIXEL RGB POV" in this project he use OptoCoupler(Opto switch) and he said "This photo shows the sensor circuitry and the nail that passes through the sensor to tell it when to start drawing each frame." So my question is: How work this OptoCoupler, where it connects.(maybe to RA5/MCLR, but then always microcontroller reset, program will start again to 000x0 address). And other question is: How to write in program to tell it when to start drawing each frame. ( I trying make similar project 8X85 RGB LED POV display). Thank you for your answers.



P.S. Sory for my english. GedasK

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brad
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Re: Simple question OptoCoupler

Post by brad » Fri Mar 11, 2011 5:17 am

You have have a look at the 8x85 pov schematic for how to make the opto coupler,
As far as how it works though is that it can connect to any input pin and in your code, once you have drawn one frame, you then stay in a constant loop where the only thing the micro controller does is checks for a logic 1 from the sensor.

When it does get that logic 1 it means it has just passed the sensor and it will then go out of the loop and then draw the next frame.

Hope tht helps!
:D

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Re: Simple question OptoCoupler

Post by GedasK » Fri Apr 22, 2011 10:28 pm

Hello, Brad thank you for your help and answer.
So my problem is:
1) Then i turn on PCB all leds turn on and not blinking.
Last edited by GedasK on Fri May 20, 2011 7:48 am, edited 2 times in total.

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Re: Simple question OptoCoupler

Post by brad » Sat Apr 23, 2011 9:21 pm

Hello, Brad thank you for the help and answer it's work then i try make in proteus program . But Today i almost finish the project and i have big problem. :) So maybe you or somebody can help and explain what is wrong (maybe you have the same problem then you first time start PCB). So my problem is:
First of all I use Switching power supply 7.5 V 1,2A. (Maybe problem is not enough power on PCB)
2) Then i turn on PCB all leds turn on and not blinking.
3)In PCB i use voltage stabilizator L7805CV. (then i remove this item, problem not disappear)
1) 7.5v 1.2 amps is plenty for this project :)
2) The LED's won't blink until you get a logic one to the sensor input pin (from the sensor) can you confirm that your sensor outputs a logic 1 when you place something in between the sensor?
3) Make sure you use your 7805 regulator! you don't want to blow up your microcontroller or chips :)

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Re: Simple question OptoCoupler

Post by GedasK » Mon Apr 25, 2011 8:22 pm

1) 7.5v 1.2 amps is plenty for this project
2) The LED's won't blink until you get a logic one to the sensor input pin (from the sensor) can you confirm that your sensor outputs a logic 1 when you place something in between the sensor?
3) Make sure you use your 7805 regulator! you don't want to blow up your microcontroller or chips
Thanks you again. :)

1) Yes i use Swithing Power suply and i can turn on 6V, 1500mA
2) Maybe i can turn off this, maybe i can clear from programing code few line and the microchip no need logic 1, just for check, because i really don't know i have logic 1 or no
3) Yes i really use 7805 i check with multimeter.

So then i turn on The PCB all RGB Led turn on, (1 - 2: RED and GREEN, 3-8: RED, GREEN, BLUE lights) but i think they can't turn on then the microship don't have logical 1. :?: :?: :?:

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Re: Simple question OptoCoupler

Post by GedasK » Mon Apr 25, 2011 11:36 pm

One more idea maybe microchip not working correctly, because in RA5/MCLR/VPP pin going 5Volts, and then the device will enter Programming mode. So maybe i need put in this pin less voltage and i got logical 1 and then microchip start blinking LED's?

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Re: Simple question OptoCoupler

Post by brad » Wed Apr 27, 2011 6:50 pm

GedasK wrote: 2) Maybe i can turn off this, maybe i can clear from programing code few line and the microchip no need logic 1, just for check, because i really don't know i have logic 1 or no

So then i turn on The PCB all RGB Led turn on, (1 - 2: RED and GREEN, 3-8: RED, GREEN, BLUE lights) but i think they can't turn on then the microship don't have logical 1. :?: :?: :?:
It should certainly work if you get rid of the code where it waits for the sensor. Although, do you have a logic probe to test the output of the sensor with?
One more idea maybe microchip not working correctly, because in RA5/MCLR/VPP pin going 5Volts, and then the device will enter Programming mode. So maybe i need put in this pin less voltage and i got logical 1 and then microchip start blinking LED's?
The MCLR pin should be disabled in the code so it should not actually reset.

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