Transcript Sensor Report

Intelligent Machines Design Laboratory
Sensor Presentation (4/18/06)
Alarm-o-bot
Andrew Joseph
TAs: Adam Barnett
Sara Keen
Instructor: A. Arroyo
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?
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.
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
IR Sensors
IR Sensor Characterization
3
• ADC values range
from 500 (about 2.4V
- close) to about 50
(about 0.4V - far).
2.5
Voltage (V)
2
IR Sensor 1
IR Sensor 2
1.5
1
0.5
0
0
1
4
9
10
11
11
12
14
15
Distance (cm)
20
27
30
34
40
47
58
74
• Distance
measurements
viable from 10cm to
80cm
CDS Sensors
CDS Sensors
5
• Low resistance in high
light, high resistance in low
light
4.5
4
3.5
Voltage
3
CDS 1
CDS 2
CDS3
2.5
2
• Voltage divider with 10k
resistor provides voltage
range from 0V to 5V
• Sensor with highest
voltage points to darkest
area in room
1.5
1
0.5
0
0
1
2
3
4
Light Intensity
5
6
7
8
RF Transmitter/Receiver
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
Conclusion
Questions?