Arduino Week 3 Lab ECE 1020 Prof. Ahmadi

Objective Data acquisition (DAQ) is the process of measuring an electrical or physical phenomenon such as voltage, current, temperature, pressure, or sound with a computer. A DAQ system consists of sensors, DAQ measurement hardware, and a computer with programmable software 1.

What Is a DAQ Device? DAQ hardware acts as the interface between a computer and signals from the outside world. It primarily functions as a device that digitizes incoming analog signals so that a computer can interpret them. The three key components of a DAQ device used for measuring a signal are the signal conditioning circuitry, analog-to-digital converter (ADC), and computer bus. Many DAQ devices include other functions for automating measurement systems and processes. For example, digital-to-analog converters (DACs) output analog signals, digital I/O lines input and output digital signals, and counter/timers count and generate digital pulses.

Schematic of a DAQ System

In Today Lab: 1.We are going to connect the light sensor to Arduino UNO board to capture data 1.Transfer the captured data to a computer 1.Analyze and plot the data on computer using MATLAB

DAQ components must be able to communicate For each and every two systems to communicate, they must speak the same language (protocols). For example in today’s lab experiment, o Arduino board must communicate with MATLAB on the computer through a known setup protocol o We upload a program on Arduino (adioes),which tells the Arduino board to listen for communication coming from MATLAB under defined terms and conditions o MATLAB is programed with a code (arduino), which know how to communicate with adioes on the Arduino board o Once the connection is established data can be transferred from Arduino to MATLAB, analyzed, and visualized.

1.Light Sensor Connect the light sensor to the Arduino UNO board as depicted in the

How to read a light sensor [How to connect it?] The sensor is connected in series with a resistor Both of which are between the +5V terminal of the Arduino and the Ground terminal They form a Voltage Ladder The data we want comes from the voltage at the point of connection between the sensor and resistor [This is what will change in response to light]

Layout

2. Program the Arduino Program the Arduino with the adioes.pde in the …/pde directory. Make sure you have chosen the right COM port and Arduino board (Arduino UNO). If programmed successfully, close the Arduino IDE software.

3. MATLAB Open MATLAB Select the …/Arduino_Lab_3 as your working directory Open the arduino_lab_3.m code file Replace the ‘COM3’ with the port your Arduino is connected to on line 11 of the code Replace 4 on line 14, val(i,1)=OBJ.analogRead(4) with the input port your light sensor in connected to Run the Script!

Sample Output Plot

Other Input Signals You can use any other input signal with amplitude in the range 6~20 Volts ( 7~12 Recommended) like, o Light Sensor o Sonar Sensor o Signals generated using a Fucntion Generator o Etc.

Reference What Is Data Acquisition? - National Instruments