Arduino mega data logger

PlatformIO project and jupiter notebook

The project focuses on:

• Configuring the Arduino Mega for precise reading of analog data from the PT100 sensor.
• Implementing compensation and calibration algorithm to enhance the accuracy of temperature readings.
• Serial communication interface for data transfer to a computer.
• Data analysis using Python for processing and visualization.
• Designing and implementing a Butterworth low-pass digital filter to smooth temperature readings.

Repo structure

• /ArduinoDatalogger: Contains the C++ source code for the Arduino Mega.
• Notes.ipynb: Python scripts for signal analysis.

Work's overview

1. The Wheatstone bridge was designed to preamplify and prefilter the temperature signal.
2. The Arduino Mega was used to collect readings using the ADC.
3. Using the serial module, the number of samples and the sampling period of the signal are set.
4. With the pandas module, data is documented with timestamps and saved to a CSV file.
5. The fast Fourier transform from the scipy module is utilized, and with matplotlib, visualization is obtained to estimate the cutoff frequency to be used in the digital filter.
6. With simpy, the z-transform of a 3rd order Butterworth filter is obtained, and by specifying the chosen sampling time and cutoff frequency, the difference equation of the filter is obtained.

Pt100 Preamp