Matlab Sensor Display

Introduction

This project was my second "accelerated" project during Junior Design. The purpose was to get us introduced to MATLAB and how to integrate outside data in real time.

Requirements

  • Use MATLAB to display raw and calibrated data for a thermistor
  • Display the resistance of an attached photocell
  • Display both above datasets in real time on a single graph with multiple Y axis.
  • Thermistor graph will display thermistor resistance, temperature based on a linear approximation, temperature based on the Steinhart-Hart model, a running average of one of the models, and finally the difference (%) between the two temperature models.
  • Design

    Block Diagram

    MATLAB Block Diagram

    Interface Definitions

    outside_system_env
  • maximum temperature of up to 100 °C
  • light from near 10 lux to over 20k lux
  • adc_usart_data
  • 10 bit unsigned integer
  • all measurements very close in time to each other
  • at least 10 sets of measurements per second
  • usart_plot_data
  • 2 dimensional array of doubles
  • plot_outside_usr
  • real time plot of last 10 seconds of data
  • line showing average of current data for each measurement type
  • display of current temperature measurement and corrected measurement
  • Final Thoughts

    This project served as a good crash course in the integration of sensors into Matlab. Learning to input outside data into the program proved to be more difficult than I had previously thought it would have been. More than anything, however, this project taught me what it was like to work on an engineering project with unwilling group. Doing a majority of the technical aspects of the project myself forced me to solve a technical challenge on my own.