Intelligent Machines Design Laboratory Sensor Presentation (4/18/06) Alarm-o-bot Andrew Joseph

1. Intelligent Machines Design Laboratory Sensor Presentation (4/18/06) Alarm-o-bot Andrew Joseph TAs: Adam Barnett Sara Keen Instructor: A. Arroyo

2. Problem • Have you ever had trouble waking up in the morning? • Do you hit the snooze button in a daze and just kept right on sleeping. • Does this cause you to miss tests, classes, or assignment turnin days?

3. Solution – Alarm-o-Bot • Hides itself based on low light intensity and distance parameters. • Avoids obstacles in the way. • The snooze button must be hit on the Alarm-o-bot to stop alarm. • Alarm-o-bot continues to hide itself after each successive snooze.

4. Sensors Types • Bump switch – act as snooze button for users to hit • CDS sensor – detect light variance (find darkest place in room) • IR sensor – obstacle avoidance • RF TX/RX pair – communicate between clock and moving robot

5. IR Sensors • ADC values range from 500 (about 2.4V - close) to about 50 (about 0.4V - far). • Distance measurements viable from 10cm to 80cm

6. CDS Sensors • Low resistance in high light, high resistance in low light • Voltage divider with 10k resistor provides voltage range from 0V to 5V • Sensor with highest voltage points to darkest area in room

7. RF Transmitter/Receiver

8. RF Transmitter/Receiver • 2400 bps baud rate • Operates at 315Mhz • -103dbm sensitivity that pulls 3.5mA for 5V operation • 10cm wire antenna used for receiver • Encoding scheme for transmission through noisy environment

10. Conclusion

11. Questions?