online signal peak detection

Hello,

I have a script for reading sensor data from a gas sensor. The sensors are connected to an Arduino, I read the data from Arduino through Matlab. Attached you can find my Matlab script. The sensor generates a signal which has a peak every 5 minutes. I want to detect the point where the signal starts to increase and the point where the signal starts to increase (the min and max value of the peak). I want to perform this online (real time). The method I perform for peak detection is: I check the last 6 values of the sensor and if there is a increase in the last three values, I detect a min value and if there is an increase of the last three values, I detect an max value (this part of the script starts from line 263). However this method is not accurate and doesn’t work well sometimes. Could anyone recommend a better way of peak detection?

I have also attached an excel file so you can see how the data of the sensor look like.

Thanks in advance

Answer 1

[Ahmed Redissi]

If you have the Signal Processing Toolbox, try using the function "findpeaks". Here's how to use it:

https://www.mathworks.com/help/signal/ref/findpeaks.html

[Rahim Yousefi]

Thank you for your answer, but as I mentioned I want to perform an online (real time) peak detection. This is not possible with the Matlab signal processing toolbox.