1. Solar Car Data Collection System Matt Boyden Rene Dupuis Ryan Lavallee 4/8/08

2. Ryan Background  Building miniature solar cars is a very common activity for teaching school-age kids about renewable energy  There are events specifically designed for building and racing solar cars that are available as educational kits

3. Ryan Project Description  What is needed is a small, light data logging device specifically designed to interface with a typical educational solar car kit.  What is needed is a small, light data logging device specifically designed to interface with a typical educational solar car kit.  The data collection system would need to collect time dependent data and then provide for the data to be uploaded and analyzed for learning.

4. Ryan Project Requirements  Record voltage and current to the motor for a specific amount of time  Interface with a computer to easily output the information in a way that can be used for educational purposes  The product must be light enough and use little power so as not to change the performance of the car

5. Matt System Diagram Data Collection Micro- Controller Motor IMotor VPanel IPanel V Wheel Sensor

6. Matt System Diagram Data Output Micro- Controller

7. Responsibilities  Ryan  Data Retrieval (PC end)  Excel VBA Programming  Circuit board layout  Matt  Signal conditioning  HC12 programming,  Data transmission to PC (HC12 end)  Rene  Wheel sensing design  Power Distribution  Casing Prototype  Website

8. Rene Power Source  Wheel Sensor requires 5V  Using (2) 3V Lithium Batteries in series for power up  Small and efficient

9. Rene Velocity Sensor Concept  Every time the wheel rotates the sensor triggers the Pulse Accumulator in the microcontroller  By knowing the wheel diameter and reading the accumulator value at regular time intervals we can calculate the speed of the car

10. Rene Velocity Sensor Circuit

11. Rene Reflective Object Sensor  Consists of an infrared emitting diode and NPN silicon phototransistor mounted side by side  Phototransistor responds to radiation emitted from diode when it senses a reflective device  Provides  High output sensing no reflection  Low output sensing reflection

12. Rene Comparator  Velocity sensor output runs into comparator  Eliminates hysteresis and rise times when changing states (high to low; low to high)  Provides quick transition intervals as comparator changes states  Provides sure output

13. Ryan Comparator Simulation

14. Rene Velocity Sensor PC Board Layout  4 wire connector from velocity sensor to main board for power and data retrieval

15. Rene Current Sensing  Use Resistor to measure current to motor  0.15Ω resistor will not affect motor performance  Easy to install in series with clip leads  Voltage will be amplified x30 and converted to positive voltage before A-D converter

16. Matt HC12 Programming  Why we chose the HC12  What does the Program have to do  How it will be accomplished  Data Transmission to PC

17. Matt Why the HC12?  Has Analog to Digital Converters  Has RS232 Chip Built into Module  16kB Flash Memory for Data  Easily programmed using available software  Can be programmed on Docking Module then transferred to Application

18. Matt Program Requirements → On Request: → Read Data from A2D Ports → Read Data from Wheel Sensor → Store Data → On Request or Timeout: → Stop Recording Data → On Request: → Transfer Data to Computer → Erase Memory

19. Matt Programming Flow Chart Start Initialization of Various Processes Start Record? Transmit? Stop Record? Read Data Store Data Time Limit? Delay MAINRECORD

20. Matt Data Transmission  Data is sent one number at a time through an RS232 connection  We are using Hyper Terminal to receive the data and capture it to a text file

21. Ryan PC Programming  How the Excel Program Works  Tutorial for Teacher  Importing Data to Excel

22. Ryan How VBA Program works  Program references.txt file  Places.txt file in predefined rows  Excel programmed to make calculations and produce graphs of all the data  Calculations:  Voltage Cell: A2D_V * 0.0049  Current Cell: ((A2D_I*0.0049)/30)/0.15Ω  Automates graph wizard process for all data

23. Ryan File Contents  The goal is to give the teacher one file where s/he will be instructed to open only the excel file and run the macro

24. Ryan Board Layout  Circuit Circuit

25. RyanSchedule

26. Budget Item Cost CostActualCost HC12$30$0 Solar Car $50$50 Reflective Sensor $2.86$0 3V Lithium Battery (2) $1.98$0 Op-amp TLV 2772 (3) $6.75$6.75 Ribbon Cable(2) $10.00$10.00 Comparator$1.74$1.74 TOTAL$103.33$68.49

27. Questions?

28. Ryan