Reference no: EM132506001

Instrumentation and Measurement

Lab 1: Zero-Span Circuits / Sensors' interface to Arduino

Objectives
i) Simulate a zero-span circuit
ii) Simulate its Interfacing with Arduino
iii) Design a suitable Printed Circuit Board

Equipment Required
i) Multisim/Partsim
ii) Virtual BreadBoard/Tinker CAD
iii) DipTrace/Altium (or any PCB software of your choice)

1. Introduction
• Review your notes on the purpose and design of zero-span circuits. For this lab the sensor input will be simulated using a sine wave (or saw tooth) (set a slow frequency i.e.10 Hz) of appropriate

• Design a zero-span circuit to interface our sensor with the Arduino:

                                                                      Input range                              Output Range

Circuit:            +300*[X] mV to -100*[Y] mV                      0 V to +5 V

To remove any ambiguity, please refer to the following correspondence between letters and numbers:

 

A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z
1	2	3	4	5	6	7	8	9	1	2	3	4	5	6	7	8	9	1	2	3	4	5	6	7	8

• Once that your output voltage is verified using the simulator within the Arduino range (10% tolerance is allowed) (0 V to +5 V), using Virtual BreadBoard you can virtually assembly your circuit and connect the Output of your circuit to the Analogue input 0 and possibly execute the acquisition script detailed at tutorial. Please note that sample rate of the acquisition script must be adjusted according to the signal frequency used, do not cause Aliasing.

• Design the PCB, you may want to include on the PCB the proper anti-Aliasing filter

• For your design you must use LM741 as operational amplifier and commercial values for passive components (see manufacturers' and suppliers' websites like Element14, Digikey etc, if you are in doubt which values to use).

2. Experiment and Lab Report
Work is individual, please use the supplied template. Tutors will demo to you a fully functional circuit using Zoom or other video-conferencing tools. Source files like schematics and Arduino program must be made available and attached to the report (zip file) at submission. This assignment will be marked according to the following marking criteria:

1. Correct use of the template i.e. figures have proper captions etc...

2. Simulation of analogue circuit fully functioning and properly explained

3. Virtual breadboard/Tinker CAD and no aliasing in acquisition script

4. PCB design

Lab 2: Characterisation and Signal Conditioning

Objectives
i) To study quality measurement parameters
ii) To study the electrical characteristics of Light Emitting Diode (LED)
iii) To study the electrical characteristics of Light Dependent Resistor (LDR)
iv) To perform signal conditions of an LDR

Equipment Required
i) Multisim/Partsim
ii) Virtual BreadBoard
iii) DipTrace/Altium

Analogue Simulation
Using a circuit simulator i.e. Partsim/Multisim, you can assembly the bridge circuit with its amplifier (see Figure 5) but cannot assembly the LED and the LDR. However, the LDR can be simulated sweeping the value of a fixed resistor for example from 1 kΩ to 10 kΩ at steps of 1 kΩ. By running the DC bias simulation PartSim can calculate for you the voltage-drop across this resistor (Rldr in Figure 5) and you can calculate its current. Because you are running this into a simulated environment you do not know the real value of the LDR resistance, you can play with the simulation with reasonable range of resistance (i.e. 1 kΩ to 10 kΩ at steps of 1 kΩ, linear characterization) filling the table below and observing the output of the amplifier you should be able to plot the characteristic at output VS input, is it linear? If not why. Other form of simulation i.e. resistor value sweep are also acceptable.

Digital simulation

For this experiment you should prepare an Arduino script that using PWM can dim a LED light (10% to 100% in at least 9 steps) and simultaneously acquire data from one single analogue channel (please be mindful about aliasing). The script must be uploaded as part of your report. Hint: see inventor kit Circuit #6.

Using Virtual BreadBoard assembly the analogue circuit you made, replace the LDR resistor with a proper sensor and make sure you connect the output into the analogue input A0. Please be mindful that you need to select a proper sample rate that does not incur in Aliasing and sized well with regards to the PWM frequency you using to run the LED.

Design the proper PCB for the circuit

Lab 3 - Characterisation and Signal Conversion

Objectives
i) To study quality measurement parameters
ii) To study the electrical characteristics of a Digital to Analogue converter (DAC)
iii) To study and assess the performances of a Digital to Analogue converter (DAC)

Arduino and Virtual BreadBoard

The R-2R ladder can be connected directly to an Arduino to operate the switches therefore you could use your DAC to construct arbitrary waveforms. You should write a simple Arduino script or program that could use your DAC to produce a periodic ramp at a frequency of your choice. Submit your Arduino script as part of your pre-work.

1. Build the circuit with R = 10k and 2R = 20k. Use wire links for D0-D3 to allow switching between LOW and HIGH.
2. Set VREF to 5 V (you should use the Arduino 5 V)
3. Save your script and please cite any reference you used to devise it. Omitting references is equivalent to plagiarism.

PCB design

For this design you may want to challenge yourself and devise an Arduino board that can implement larger bit count DACs or other technologies of DACS i.e. digital potentiometers

Attachment:- Instrumentation and Measurement Lab.rar

Attachment:- Characterisation and Signal Conditioning.rar