Transcript MODULE 2 Rhett Board.. - Multimedia Communications Laboratory

MODULE 2: Signals / Rhett Board
SUMMER CHALLENGE
Electrical Engineering: Smart Lighting
Michael Rahaim, PhD Candidate
Multimedia Communications Lab
Smart Lighting Engineering Research Center
Boston University
[email protected]
Module 2: Signals / The Rhett Board
07/08/2014
Overview
Boston
Smart
UniversityLighting
Slideshow Title Kit
Goes Here
 Voltage and Current
 What is a signal?
 Generating & observing signals
 The Rhett Board and Mobile Studio
 Experiments
 Time Domain - Digital Signals
 Time Domain - Analog Signals
 Frequency Domain
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Module 2: Signals / The Rhett Board
07/08/2014
Teams
 Team 1: Konstantinos & Alexis
Boston University Slideshow Title Goes Here
 Team 2: Andrea & Aris
 Team 3: Jaun Pablo & Arjun & Ignacio
 Team 4: Christy & Alexandra
 Team 5: Kaileigh & Elena
 Team 6: Nithin & Simon
 Team 7: Adam & Andrew
 Team 8: Greg & Iraj
 Team 9: Jeff & Eric
 Team 10: Kento & Chandler
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Module 2: Signals / The Rhett Board
Smart Lighting Kit
Boston University Slideshow Title Goes Here
Course website:
Mobile Studio Project:
07/08/2014
Smart Lighting Lab kit contents:
• 2 Rhett Boards
• 2 USB to micro-USB cables
• 2 Breadboards
• 2 Wiring kits
• 2 Alligator Clips
• Resistors and capacitors
• Red, green and white LEDs
• Photodiode(PD)
• Operational amplifier (Op-Amp)
• Exclusive-OR (XOR) gate
• Lens
• Flashlight
• Tape measure
• Protractor
• Speaker
• Headphones
• Transceiver printed circuit board (PCB)
o Board Components
o 2 USB to serial cables (FTDI)
http://hulk.bu.edu/courses/SmartLight/2014/
http://www.mobilestudioproject.com/
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Module 2: Signals / The Rhett Board
07/08/2014
Static Electricity
Boston
Atoms
vs Ions
University Slideshow Title Goes Here
 Atoms consist of neutrons, protons, and electrons
 Neutrons are neutral, protons are positive, electrons are negative
 Ions are electrically charged atoms (more or less electrons than protons!)
e
NN
P P NP
P NN
N P P
e
e
NN
P P NP
P NN
N P P
e
e
e
e
e
 Charge
e
e
e
 Measure of the difference in protons and electrons
 Typically measured in Coulombs [C]
 Charge causes objects to experience an attractive or repulsive force
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Module 2: Signals / The Rhett Board
07/08/2014
“Dynamic” Electricity
Boston
Insulators
and Conductors
University Slideshow Title Goes Here




Electrons in insulators have little freedom to move
Electrons in conductors easily move from atom to atom
Insulators: Rubber, Cotton, Wood, etc.
Conductors: Silver, Copper, aluminum, etc.
 Electric Current
 Electric force tends to disperse charge if possible
 Current is the rate of flow of charge (opposite the flow of electrons)
 Current is measured in Amperes [A] or [C/s]
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Module 2: Signals / The Rhett Board
07/08/2014
Circuits
Boston
Continuous
flow requires an “infinite” source of electrons
University Slideshow Title Goes Here
Source
Source
Sink
Sink
 What is another “circuit” you’ve heard of?
What is flow rate of
marbles in this
scenario?
What is missing?
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Module 2: Signals / The Rhett Board
07/08/2014
Voltage
Boston
Another
Analogy: Water Slide
University Slideshow Title Goes Here





Pump moves water back to the top
Pumping water to the top requires energy
This increases the Potential Energy of the water
As water flows down the slide, it releases stored energy
Water at the top of higher slides has more PE relative to ground
 Relation to electric circuits
 Batteries act as the “pump” in an electric circuit
 Electric Potential, or Voltage [V], is the Electric PE per unit charge
Buildup of charge at the battery terminal
forces electrons to move through the circuit
Electrons flow from the negative
terminal to the positive terminal
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Module 2: Signals / The Rhett Board
07/08/2014
Voltage
Boston
Differential
University Slideshow Title Goes Here
 Potential energy is related to the “drop” from one level to another
 Voltage is the electric potential difference between two points
 Ground
 In the water slide analogy, the ground can be a common reference
 Similarly, electrical “ground” can be a common reference
 Ground isn’t always exactly the same across devices!
 Polarity
 Some devices only allow current to flow in one direction
 LEDs are polarized components.
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Module 2: Signals / The Rhett Board
07/08/2014
Signal Analysis
Boston
What
is “Time Domain”
University Slideshow Title Goes Here
 Types of Signals
 As EE’s, we want to convert to ELECTRICAL signals!
 Digital vs Analog (Discrete vs Continuous)
 Input vs Output
Output
Signal Generator
Input
Output
System
Input
Signal Measurement
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Module 2: Signals / The Rhett Board
07/08/2014
Amplitude
Signal Analysis
Boston
Waveform
University Slideshow Title Goes Here
…
t
period
 Signals repeated indefinitely
Phase
Shift
 Amplitude
 Instantaneous vs Average
 Period and Frequency
 Period: Duration of repeating component of the signal [s]
 Frequency: Number of repetitions per second [Hz]
 Phase
 Ranges from 0 to 360 degrees
 Single Ended (SE) vs Differential (DIF)
 SE: Voltage difference between a point and “ground”
 DIF: Voltage difference between point A and point B
 AC vs DC coupling
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Module 2: Signals / The Rhett Board
07/08/2014
Digital Signal
Boston
Discrete
level signals
University Slideshow Title Goes Here
 Consider 2-level (binary) signals that are “on” or “off”
 How many states do a car’s tail lights have?
 Variations in time send information!
 Pulse Width and Duty Cycle
Pulse
Width
Pulse
Width
Amplitude
period
t
Amplitude
t
period
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Module 2: Signals / The Rhett Board
07/08/2014
Signal Generation / Observation
Boston University Slideshow Title Goes Here
Function Generator
Oscilloscope
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Module 2: Signals / The Rhett Board
07/08/2014
Rhett Board Pinout
Boston University Slideshow Title Goes Here
Digital I/O 1 - 16 : Digital Input/Output Pins
PWM1 : Pulse Width Modulation, Channel 1
PWM2 : Pulse Width Modulation, Channel 2
3.3V : +3.3V DC
DGND : Digital ground
Horizontal Connector
(left to right)
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Module 2: Signals / The Rhett Board
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Experiment I
Boston
Mobile
Studio Introduction
University Slideshow Title Goes Here
 Digital I/O
 Function Generator
 Oscilloscope
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Module 2: Signals / The Rhett Board
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Analog Signals
Boston University Slideshow Title Goes Here
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Module 2: Signals / The Rhett Board
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Analog Signals
Boston University Slideshow Title Goes Here
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Module 2: Signals / The Rhett Board
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Rhett Board Pinout
Boston University Slideshow Title Goes Here
-V: -4V DC (capable of providing ~ 50mA)
+V: +4V DC (capable of providing ~ 50mA)
Impedance Analyzer (not released)
Impedance Analyzer (not released)
GND : Analog ground
Speaker - : Audio Out
Speaker + : Audio Out
GND : Analog ground
Phones R : Audio, Out Right Channel
Phones L : Audio, Out Left Channel
GND : Analog ground
AWG2 : Arbitrary Waveform Generator, Channel 2
GND : Analog ground
AWG1 : Arbitrary Waveform Generator, Channel 1
A2- : Analog, Channel 2 Input
GND : analog ground
A2+ : Analog, Channel 2 Input
A1- : Analog, Channel 1 Input
GND : Analog ground
A1+ : Analog, Channel 1 Input
Vertical Connector
(top to bottom)
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Module 2: Signals / The Rhett Board
07/08/2014
Experiment II
Boston
Mobile
Studio – Analog Signal Generation
University Slideshow Title Goes Here
 Oscilloscope for reading input
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Module 2: Signals / The Rhett Board
07/08/2014
Frequency Domain Analysis
Boston
Sine
waves generate a “pure” frequency
University Slideshow Title Goes Here
 Time domain signals have a frequency domain representation and
can be generated with a combination of sine waves
 Harmonics are integer multiples of a signals fundamental frequency
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Module 2: Signals / The Rhett Board
07/08/2014
Experiment III
Boston
Spectrum
Analyzer
University Slideshow Title Goes Here
 Arbitrary Waveform Generator (AWG)
 Function generator output is a subset of potential AWG signals!
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Module 2: Signals / The Rhett Board
07/08/2014
Recap
Boston
References:
University Slideshow Title Goes Here
 http://www.physicsclassroom.com/
 http://www.allaboutcircuits.com/
 What did you
today?
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