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Need help in ECG circuit and arduino code to read BPM

Czy

Dec 12, 2022
2
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Dec 12, 2022
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Hi, everyone I am currently doing an ecg project and desperately need help. I used opamp AD623 and LM358 to come out with an ecg circuit but when connected to the oscilloscope it is showing a lot of noises in the signals from the circuit. Does anyone have any idea on how to reduce noise from the opamp ECG circuit? Below is the image and link for the schematic diagram.


I am also working on Arduino code to take measurement of BPM and show ecg signal from my circuit. Does anyone have any idea on the Arduino code for this or sample code to share?

Thanks in advance. Any help is appreciated.
 

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danadak

Feb 19, 2021
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Feb 19, 2021
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I dont see any bypass caps on the board for the LM358 and the IA ?

Put your scope on infinite persistence, look at supply rails, and try a
combination of a 10 uF or more tantalum in parallel with a .1 uF
ceramic, and observe the the pk-pk noise before and after addition
of the caps. Remember to clear display after each run of the scope
on infinite persistence.

The AD623 inputs should be grounded while working on power supply
noise.

The input CM range of the AD623 is limited to Vs - 1.5V for highest
level input. So that means you input range to the AD623 is basically
ground to 3.5V. So I would set Vref up to 1/2 that to max range sensor
can be worked with. Just change one of the R2's at input of OP1 to
achieve that. Calc thru classic V divider equation.


Regards, Dana.
 

Czy

Dec 12, 2022
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Dec 12, 2022
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Hi, I have manage to come out with a better ecg waveform using AD623 and LM342N opamp. I have used a different schematic diagram and the waveform is better than previous one. However, I do not know how to code using arduino to get the ecg waveform from serial plotter and I also need to calculate the bpm reading taken. May I know anyone have any source code that is working. Thanks in advance.
http://www.sharpround.com/wp-content/uploads/2014/11/ecg_handout.pdf
 

Bluejets

Oct 5, 2014
6,901
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Oct 5, 2014
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6,901
Fritzing are a right pia at the best of times....yours is so small cannot make out and connection details....
 
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