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Flowcode programming

Discussion in 'Microcontrollers' started by kokos, Mar 18, 2010.

  1. Gobbledok

    Gobbledok Active Member

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    Cool let me know how you go and we can troubleshoot from there :p
     
  2. kokos

    kokos Member

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    Hi again :p

    i constracted the circuit you posted above and placed the IR LED oposite to photodiode. when the power is on the LED is on and when i place my finger between the sensors the led turns off and i am trying to adjust the trimmer but i cant see any pulse. i also increased and decreased the values of R1 and R2 but still icant see any pulse. do you think that the signal need to be amplified first?

    Thanks
     
  3. Gobbledok

    Gobbledok Active Member

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    You may need to amplify the signal first. I really have no idea how the IR sensor will react with your pulse. It all depends on the difference of light when a heart beat occurs.

    Are you able to crudely measure with a multimeter the voltage at the top of R1 when the meter is on your finger?
     
  4. dave

    Dave New Member

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  5. kokos

    kokos Member

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    yeah i can do that. what voltage i should expect when my finger is between the sensors?
     
  6. Gobbledok

    Gobbledok Active Member

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    I have no idea. I don't know what to expect from the sensor.

    Just reading about it some people are saying that you have to use a red LED and an IR LED to measure pulse. Is it possible to measure pulse using the sensor this way? I was just going off what you had already done.
     
  7. kokos

    kokos Member

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    yeah i saw that somewhere.they used a red led and an IR led but also with only an IR led it can measure the pulse. do you know if i must use a current to voltage converter first after to amplify the signal and after to use the circuit that you posted? i am kind of confused here..
     
  8. Gobbledok

    Gobbledok Active Member

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    As it is you won't need a current to voltage converter.

    A photodiode will increase its current in the presence of light. That will create a voltage drop across R1 which is what the comparator reads.

    I really have no idea how sensitive your sensor needs to be, or what the photodiode on the other side of your finger sees. If the difference between pulse and no pulse is tiny, then it is only a tiny voltage change you are trying to detect.

    If someone else says you need a current to voltage converter, they might know more about using this sort of sensor than me.
     
  9. sharilewis

    sharilewis New Member

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    I've been meaning to have a play with flowcode for a while and so thought this would be a good time. I implemented your code without the LCD stuff but with a few changes. I've looked at the C code produced and it appears to be correct.


    Yuasa NP7-12
     
  10. Pommie

    Pommie Well-Known Member Most Helpful Member

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    That appears to be a direct quote of my post (#15). What was the purpose of doing that?

    Mike.
     
  11. Gobbledok

    Gobbledok Active Member

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    Spam by the looks of it.
     
  12. kokos

    kokos Member

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    hello Gobbledok
    finally my design works))
    i attached one schematic diagram and can you please tell me in which mode the photodiode works?(photovoltaic or photoconductive). also can you please tell me the first op-amp is inverting or non-inverting? and what about the second op-amp inverting or non-inverting?

    Thanks
    kokos
     

    Attached Files:

  13. eirah

    eirah New Member

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    hi, i want to make the heart rate counter to be my project in microcontroller and program it using flowcode, could you send me the schematic and how should i make the flowcode

    tnx in advance
     

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