1. Company LOGO Infrared Remote Controller for Digital Thermometer Sunghwa Jung & Xing Wang

2. Table of Contents 1. Project Introduction 2. Operation Outline 5. How to Decode 6. The Problems We Met 3. Modulation & Demodulation 7. Conclusion 4. Data Format

3. Project Introduction Remote controller Digital thermometer On Temp > Trigger On after signal received Flash 5 times after trigger changed Amplifier IR LED IR Receiver Sensor

4. Operation Outline { Decode IR Signal; Change & Display Trigger; } { Decode IR Signal; Change & Display Trigger; } While (1) { Disable External Int; Convert Temperature; Enable External Int; Display Temperature; } While (1) { Disable External Int; Convert Temperature; Enable External Int; Display Temperature; } Main Ext Int

5. Modulation & Demodulation Modulation Demodulation Carrier (36kHz) Data Modulated data with carrier Demodulated data

6. Data Format T 24 carrier periods HeadData Stop_bit 4T 96 carrier periods 2T 48 carrier periods T 01000111 TRTR RE T

7. How to Decode TimeData 4THead 2T0 3T1 2T & 9 th bitStop bit 01000111 HeadData Stop_bit Record Time every Ext Int Compare Time with data format Reset IR Receiver Sensor DataOperation 1100Trigger++ 0011Trigger-- Data Data==1 Y N Ext Int triggered at

8. The Problems We Met 1/3 Carrier Duty Cycle Unstable Receiver Signal Use PIC16F877 Noise Causes Ext Int Memory Upper Limit 1/3 Carrier Duty Cycle Disable Ext Int during conversion

9. Conclusion 1 2 3 4 Remote controller uses IR communication. Transmitter : Data is modulated with carrier and amplified. Receiver : Amplify and demodulate the input signal, then decode data.

10. Thank You Thank you Dr. Song! Thank you everyone!