How to assign smoothed data from serial into an array

Using Arduino Programming Questions
1

Hello everyone. I am now using Arduino and Pulse Sensor to measure one's heart rate. But now I do have a problem which makes me crazy.
I make a little change to the Smooth function in the library, which makes my data acceptable better. If I directly read it from the serial, and use Serial.println(average); it looks like a fairly good PPG signal series.

image
image950×382 9.62 KB

So I just want to store these data into an array, which can be used for later calculation. But the problem occurs. I write x[index] = average; just after the previous println sentence, which can, I assume, can guarantee that the value will be stored as soon as possible. However, when I finish storing the data. I find that what is printed from the x[] array is entirely different from the "acceptable" series I mentioned before.
I am really confused and wonder if anyone may answer me why. :sweat_smile:

2

The data read from x[] with for loop are like this:

image
image974×372 8.23 KB

I think it can be seen that there could be something related with period. But I want to make data in x [] as similar with serial data as possible. Can someone give me hints or suggestions?
Thanks a lot.

3

Post your code!

5

My code looks as shown here

6

Yes, I have posted it now.

7

Hello
do you think that the selected smooth function ist the correct function to flatten the noise of the raw data?

9

I am not so sure. But that’s modified from the code in the Arduino library. If I execute Serial. println(average); the result is just like the picture I posted in #1.
Do you have any advice?

10

Hello
Well you could use a search engine and search for AnalogSmooth.h

11

Do you mean the built-in example of IDE?

12

I meant the search engine for the world wide net.

13

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