Flowcode programming

[Gobbledok]

Thanks Gobbledok i will build and test the circuit you posted above with IR LED 940nm and a photodiode.

Thanks
kokos

Cool let me know how you go and we can troubleshoot from there

 

[kokos]

Cool let me know how you go and we can troubleshoot from there

Hi again

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

 

[Gobbledok]

Hi again

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

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?

 

[kokos]

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?

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

 

[Gobbledok]

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

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.

 

[kokos]

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.

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..

 

[Gobbledok]

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..

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.

 

[sharilewis]

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.


**broken link removed**

 

[Pommie]

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.

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

Mike.

 

[Gobbledok]

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

Mike.

Spam by the looks of it.

 

[kokos]

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.

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

 

[eirah]

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