Ready to Party? 

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

 Can’t decide where to go on a Friday night?  Not sure whether the place you go is what you expected? Problem Identification Introduction  Allow users to check real-time information on:  Population at bars  Atmosphere Statement of Purpose A Different Kind of… “Bar”-O-Meter

Objectives  Supply 5V DC 500 mA  Amplify analog signal to estimate activity on tiles  Parse/analyze data on computer  Automatically upload data online Intended Function  Develop sensors to measure activity  Realize communication from sensors to PC via Bluetooth  Establish online portal to share information  Design entire system for < $400 Project Goals  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 Benefits to Community  Sensing pads powered by wall power to lower cost  Present activity level in the form of an interactive map  Display bar information online Product Features 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.

Overall Block Diagram Power Supply Sensor Receiver/Transmitter Computer Display 5V 500mA Bluetooth RN-42 Sensing PadsAmplifierArduino Computer

Original Design  Diode: D1N4002  Capacitor: 330 uF  Ziner Diode: D1N5733 (5.1V)  Resistor: 500 Ohm Parts Information  Lowers wall power to desired voltage level and converts AC to DC  Provides 5V 500mA to supply electricity to the entire system  Consists of transformer, rectifier, smoother, and regulator Power Module Description Circuit Design

Original Design  Resistor: 1kΩ  Variable Resistor:  Pre-made pressure- controlled resistor  Op-Amp: AD620 Parts Information  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. Sensor Module Description Circuit Design

Requirements & Verifications  Varies monotonically with input  Amplifies analog voltage signal  Responses to sudden changes  Microcontroller  preset value for each sensor pad  converts analog to digital Sensor Module  Sufficient power from wall plug  Transformer is working properly  Rectifier filters out negative voltage  Output voltage is smoothed with ripple voltage Power Supply  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 Transmitter/ Receiver  Receives readable information  Java program is robust to handle information inflow  Upload information to website  Website can store all data without loss of information Computer Display

Requirements & Verifications  Varies monotonically with input  Amplifies analog voltage signal  Responses to sudden changes  Microcontroller  preset value for each sensor pad  converts analog to digital Sensor Module  Sufficient power from wall plug  Transformer is working properly  Rectifier filters out negative voltage  Output voltage is smoothed with ripple voltage Power Supply  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 Transmitter/ Receiver  Receives readable information  Java program is robust to handle information inflow  Upload information to website  Website can store all data without loss of information Computer Display

Requirements & Verifications  Varies monotonically with input  Amplifies analog voltage signal  Responses to sudden changes  Microcontroller  preset value for each sensor pad  converts analog to digital Sensor Module  Sufficient power from wall plug  Transformer is working properly  Rectifier filters out negative voltage  Output voltage is smoothed with ripple voltage Power Supply  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 Transmitter/ Receiver  Receives readable information  Java program is robust to handle information inflow  Upload information to website  Website can store all data without loss of information Computer Display

Requirements & Verifications  Varies monotonically with input  Amplifies analog voltage signal  Responses to sudden changes  Microcontroller  preset value for each sensor pad  converts analog to digital Sensor Module  Sufficient power from wall plug  Transformer is working properly  Rectifier filters out negative voltage  Output voltage is smoothed with ripple voltage Power Supply  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 Transmitter/ Receiver  Receives readable information  Java program is robust to handle information inflow  Upload information to website  Website can store all data without loss of information Computer Display

Requirements & Verifications  Varies monotonically with input  Amplifies analog voltage signal  Responses to sudden changes  Microcontroller  preset value for each sensor pad  converts analog to digital Sensor Module  Sufficient power from wall plug  Transformer is working properly  Rectifier filters out negative voltage  Output voltage is smoothed with ripple voltage Power Supply  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 Transmitter/ Receiver  Receives readable information  Java program is robust to handle information inflow  Upload information to website  Website can store all data without loss of information Computer Display

Power Supply  Diode: D1N4002  Capacitor: 330 uF  Ziner Diode: D1N5733 (5.1V)  Resistor: 500 Ohm Parts Information  Lowers wall power to desired voltage level and converts AC to DC  Provides 5V 500mA to supply electricity to the entire system  Consists of transformer, rectifier, smoother, and regulator Component Description Circuit Design

Power Supply testing

Velostat Pressure Sensor  Velostat:  250 x 250 x 1mm  Aluminum Foil:  200 x 200mm Parts Information  Resistance ranges from 1Ω - 3kΩ  Resistance varies monotonically with input pressure  Three layers per sensing pads  Use aluminum foil as current conductor Component Description Component Design  Normal: 3kΩ  Standing: 2-3Ω  Moving: ±0.3Ω Testing

Direct Current Bridge Information  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 Requirements Component Design Vo Vin A B C D

Direct Current Bridge Testing

Direct Current Bridge Testing Cont’d

Differential Amplifier Information  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 Requirements Component Design

Differential Amplifier Testing

Differential Amplifier Testing Cont’d

Sensor Module Circuit

Arduino Uno Microcontroller  Input:  Voltage: 5V  Signal: A0 – A3 from four sensing pads  Output: TX to Bluetooth Information  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 Description Component Design Ground Vin = 5V Inputs from Sensor pads BT

Bluetooth (via Processing)  Input:  Voltage: 5V  Signal: RX connected to TX on Arduino  Output:  Paired with PC Information  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 Description Component Design Ground Vin = 5V Connected to TX pin on Arduino Board

Computer Display  Input:  Text file containing data for sensor pads  Output:  Display data on monitor Information  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 Description Component Design

Successes & Challenges  PIC microcontroller  CCS C Compiler not compatible with MPLAB  Connection with Bluetooth  Hard to establish connection through Serial Port  Cannot handle data faster than 100ms  Delay in writing data to file  Low cost for sensing pad  $20 for 10ft x 2ft  High sensitivity  Varies from 3k Ω to 3 Ω  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!