If possible, post your project here.
The ECG signal requires a differential amplifier circuit with a small positive bias.
(useful signal less than 1mV against a common-mode signal up to hundreds of millivolts)
Your signal is very similar to (50 / 60Hz)
Thank you for your reply, Evgeniy,!
The first two amplifiers I tried to simulate an instrumentation amplifier. This configuration I got here: https://www.cypress.com/file/53376/download
The third amplifier I put it based on the circuit that is presented in this video(in the minute: 7:20): Électrocardiographe / Moniteur cardiaque / DIY Electrocardiograph - YouTube
I have 99% sure that the signal I got is an ECG signal because when I do not put the electrodes on my skin, it is a constant. I will post above the link to download my project:
An observation: in main.c I multiply the signal by -1 because I got it inverted after the third amplifier.
You are using unipolar power supply for the PSoC.
Therefore, you must ensure that the input bias is at least> 0 above 100mV.
In addition, a lower reference voltage for ADC can be used.
odyssey1 processed signals less than 0 (up to +/- 100mV) at lower reference voltage for the ADC.
But I don't remember which topic.
I tested the signal simulator that you sent me and I got this signal:
So, I have some questions that I would like to ask you:
Tha ADC is by passed, what is its reference? Is it the E2 pin?
Where the extern variable WaveDAC8_1_wave2 is defined and declared?
Why the ECG_Wave is not used?
Do you think that my ECG circuit is correct?
Thank you very much for your reply, Evgeniy!
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1. ADC has internal Vref and requires a bypass capacitor (pin P0 (4)) so it was in your project
2. extern variable WaveDAC8_1_wave2 is defined and declared on line 35 (replacement procedure at lines 33-36)
3. ECG_Wave - real ECG + 50Hz noise is not used in this project.
4. The resistor R_1 is 11 ohms (use 50-100 ohms to start)
The ECG signal is very small (<1mV), hidden in a huge interference signal (50/60 Hz) and may have an offset from skin-galvanic reactions (up to + - 300 mV)
Look for a description of the real ECG signal and its components, for example, this.
Therefore, you will have to use a differential amplifier with capacitors at the input.
here are my old projects (PSoC5, russian)