Ready to Party?

http://www.youtube.com/watch?v=NcBik_REx7k
A Different Kind of “Bar”-O-Meter
Presented by: Group #50
Chen Hu, Tuo Liu, Yiming Song
Project Outline
Introduction & Objectives
Original Design, Requirements, & Verifications
Project Build & Function Tests
Successes and Challenges
Additional Testing Performed
Recommendations for Further Work
Introduction
Problem Identification
 Can’t decide where to go on a
Friday night?
 Not sure whether the place you
go is what you expected?
A Different Kind of…
Statement of Purpose
 Allow users to check real-time
information on:
 Population at bars
 Atmosphere
Objectives
While we aim for our system to enhance the communication between businesses and their customers, we have outlined
certain specific objectives to be accomplished over the course of the semester.
Project Goals
 Develop sensors to measure activity
 Realize communication from sensors
to PC via Bluetooth
 Establish online portal to share
information
 Design entire system for < $400
Benefits to Community
 Affordable cost for bars/clubs to
install and setup
 Long-term investment in
marketing effort for bar owners
 Easily accessible live information
online for customers
Intended Function
 Supply 5V DC voltage @ 500 mA
 Amplify analog signal to estimate
activity on tiles
 Parse/analyze data on computer
 Automatically upload data online
Product Features
 Sensing pads powered by wall
power to lower cost
 Present activity level in the form
of an interactive map
 Display bar information online
Overall Block Diagram
Sensing Pads
5V DC @
500mA
Computer
Display
Sensor
Power Supply
Amplifier
Arduino
Bluetooth RN-42
Receiver/Transmitter
Computer
Original Design
Power Module Description
 Lowers wall power to desired voltage level and converts AC to DC
 Provides 5V DC @ 500mA to supply electricity to the entire system
 Consists of transformer, rectifier, smoother, and regulator
Circuit Design
Parts Information
 Diode: D1N4002
 Capacitor: 330 uF
 Ziner Diode: D1N5733
(5.1V)
 Resistor: 500 Ohm
Original Design
Sensor Module Description
 Sensor module intends to measure the resistance of the sensor pad and
estimate the weight based on the figures.
 We implement this module by designing a module that allows for variable
resistor and amplify the current that goes through the circuit.
Circuit Design
Parts Information
 Resistor: 1kΩ
 Variable Resistor:
 Pre-made pressurecontrolled resistor
 Op-Amp: AD620
Requirements & Verifications
Power Supply




Sufficient power from wall plug
Transformer is working properly
Rectifier filters out negative voltage
Output voltage is smoothed with
ripple voltage
Transmitter/ Receiver
 Sends data to PC via Bluetooth
without loss of information
 Truncates data to the digits we need
 Generates text file with original data
 Updates data automatically every
100ms
Sensor Module




Varies monotonically with input
Amplifies analog voltage signal
Responses to sudden changes
Microcontroller
 preset value for each sensor pad
 converts analog to digital
Computer Display
 Receives readable information
 Java program is robust to handle
information inflow
 Upload information to website
 Website can store all data without
loss of information
Requirements & Verifications
Power Supply




Sufficient power from wall plug
Transformer is working properly
Rectifier filters out negative voltage
Output voltage is smoothed with
ripple voltage
Transmitter/ Receiver
 Sends data to PC via Bluetooth
without loss of information
 Truncates data to the digits we need
 Generates text file with original data
 Updates data automatically every
100ms
Sensor Module




Varies monotonically with input
Amplifies analog voltage signal
Responses to sudden changes
Microcontroller
 preset value for each sensor pad
 converts analog to digital
Computer Display
 Receives readable information
 Java program is robust to handle
information inflow
 Upload information to website
 Website can store all data without
loss of information
Requirements & Verifications
Power Supply




Sufficient power from wall plug
Transformer is working properly
Rectifier filters out negative voltage
Output voltage is smoothed with
ripple voltage
Transmitter/ Receiver
 Sends data to PC via Bluetooth
without loss of information
 Truncates data to the digits we need
 Generates text file with original data
 Updates data automatically every
100ms
Sensor Module




Varies monotonically with input
Amplifies analog voltage signal
Responses to sudden changes
Microcontroller
 preset value for each sensor pad
 converts analog to digital
Computer Display
 Receives readable information
 Java program is robust to handle
information inflow
 Upload information to website
 Website can store all data without
loss of information
Requirements & Verifications
Power Supply




Sufficient power from wall plug
Transformer is working properly
Rectifier filters out negative voltage
Output voltage is smoothed with
ripple voltage
Transmitter/ Receiver
 Sends data to PC via Bluetooth
without loss of information
 Truncates data to the digits we need
 Generates text file with original data
 Updates data automatically every
100ms
Sensor Module




Varies monotonically with input
Amplifies analog voltage signal
Responses to sudden changes
Microcontroller
 preset value for each sensor pad
 converts analog to digital
Computer Display
 Receives readable information
 Java program is robust to handle
information inflow
 Upload information to website
 Website can store all data without
loss of information
Requirements & Verifications
Power Supply




Sufficient power from wall plug
Transformer is working properly
Rectifier filters out negative voltage
Output voltage is smoothed with
ripple voltage
Transmitter/ Receiver
 Sends data to PC via Bluetooth
without loss of information
 Truncates data to the digits we need
 Generates text file with original data
 Updates data automatically every
100ms
Sensor Module




Varies monotonically with input
Amplifies analog voltage signal
Responses to sudden changes
Microcontroller
 preset value for each sensor pad
 converts analog to digital
Computer Display
 Receives readable information
 Java program is robust to handle
information inflow
 Upload information to website
 Website can store all data without
loss of information
Power Supply
Component Description
 Lowers wall power to desired voltage level and converts AC to DC
 Provides 5V DC @ 500mA to supply electricity to the entire system
 Consists of transformer, rectifier, smoother, and regulator
Circuit Design
Parts Information
 Diode: D1N4002
 Capacitor: 330 uF
 Ziner Diode: D1N5733
(5.1V)
 Resistor: 500 Ohm
Power Supply testing
Velostat Pressure Sensor
Component Description




Resistance ranges from 1Ω - 3kΩ
Resistance varies monotonically with input pressure
Three layers per sensing pads
Use aluminum foil as current conductor
Component Design
Parts Information
 Velostat:
 250 x 250 x 1mm
Testing
 Normal: 3kΩ
 Standing: 2-3Ω
 Aluminum Foil:
 200 x 200mm
 Moving: ±0.3Ω
Direct Current Bridge
Component Requirements
 Outputs negative voltage difference when no one is standing on the sensing pad
 Outputs positive voltage difference of ~2V
 Derived values for resistors based on the Velostat resistance change
Component Design
Information
B
𝑅4
𝑅1
A
C Vo
𝑅2
D
𝑅3
Vin
 Input:
 Voltage: 5V
 Sensing Pad
 120Ω Resistors x 3
 Output: Vo =
R1 R4 −𝑅2 𝑅3
(𝑅1 +𝑅2 ) R3 +R4
Vin
Direct Current Bridge Testing
Direct Current Bridge Testing Cont’d
Differential Amplifier
Component Requirements
 Rectifies negative value to ~0V
 Amplifies positive value by two times
 Higher resolution with amplified signal since Arduino Board can only read up to
two places after decimal point
Component Design
Information
 Input:
 𝑉1 and 𝑉2 from DC
Bridge
 𝑅1 = 𝑅2 = 1.5𝑘Ω
 𝑅𝑓 = 𝑅𝑔 = 3𝑘Ω
 Output:
Vout =
𝑅𝑓 +𝑅1 𝑅𝑔
𝑅𝑔 +𝑅2 𝑅1
𝑅𝑓
𝑉2 − 𝑅 𝑉1
1
Differential Amplifier Testing
Differential Amplifier Testing Cont’d
Sensor Module Circuit
Arduino Uno Microcontroller
Component Description




Converts analog signal (0 – 5V) from the amplifiers to digital data
Supports up to 6 inputs per Arduino Uno board
Sends digital data to Bluetooth for transmission
No time delay
Component Design
Information
 Input:
 Voltage: 5V
 Signal: A0 – A3 from
four sensing pads
Ground
Vin = 5V
Inputs from
Sensor pads
 Output: TX to Bluetooth
BT
Bluetooth (via Processing)
Component Description




Receives digital data from Arduino Uno Microcontroller
Truncates data to only the four values
Transmits data to PC every 100ms
Generates data text file to allow for PC to read information
Component Design
Information
 Input:
 Voltage: 5V
 Signal: RX connected
to TX on Arduino
Vin = 5V
Ground
Connected to
TX pin on
Arduino Board
 Output:
 Paired with PC
Computer Display
Component Description




Reads data from text file to obtain alpha values for each sensing pad
Generates an RGB value randomly
Populates data into respective blocks
Updates constantly without changing display if input data is null
Component Design
Information
 Input:
 Text file containing
data for sensor pads
 Output:
 Display data on
monitor
Successes & Challenges

PIC microcontroller


Connection with Bluetooth


CCS C Compiler not
compatible with MPLAB
Hard to establish connection
through Serial Port
Cannot handle data faster
than 100ms

Delay in writing data to file

Low cost for sensing pad


High sensitivity


$20 for 10ft x 2ft
Varies from 3kΩ to 3Ω
Easy to install than wooden
floor


Put on like a carpet
Easy to maintain
Recommendations for Future Work
Upload live
information to
website
Develop mobile
app to increase
accessibility
Provide historical
data tracking /
referencing
Special Thanks to…




Prof. Scott Carney (Instructor)
Igor Federov (Teaching Assistant)
Mark Smart from machine shop
… and everyone who contributed to our success!
Questions / Comments?
Thank You!