Easy on the Tini
Cell phone detector
Bill Barker
Carey Davis
Ben Irwin
Travis Majors
Description and Goals
To create a robot that detects RF signals
(cell phone signals) then moves toward the
strongest signal.
Notifies cell phone user about use in that
area.
Outline of Approach
Create a robot with two servo motors
Fashion RF detecting antenna(s) on the
robot chassis
Mount IR sensors to aid robot movement
Use display, lighting, sounds, etc. to deter
cell phone use
Design a microcontroller to interface the
systems
Hardware Implementation
Tuned Yagi
Antenna
Low Noise
Amplifier
Diode
Rectification
Circuit
Sharp IR
Detectors (3)
Digital Compass
Module
A/D Input I2C Interface
Microcontroller
MSP4301611
JTAG
Interface
PWM Signal Outputs
Signal
Disruption
Motor
Drivers
ServoDisc
Motors
Data/ Programming
interface
Software Flow Diagram
no
System Ok
yes
Read Compass
and Antenna
Value
no
1
Move Forward
2
no
no
Object?
Timer
Going?
Try to detect
signal
yes
Count=2?
2
2
Turn to match
degrees of
strongest signal
yes
no
yes
Turn
Find
Strong
Signal?
Rotated
360o?
90o
3
Forward
yes
yes
1
Rotate 180o
Signal Disruption
Reached Object?
no
no
3
Count + 1
Signal
still
there?
yes
The Robot
Metal platform from
previous project
Two 9FGHD Ferrite
Series ServoDisc
Motors
Robot Movement
Autonomous

Object Detection


Infra-Red
Home Base Detection

RF
Programmable Search Pattern

Signal Detection Sweep
Identify and approach appropriate signal
Scenario#1
No Signal Found
Signal Found
Object Detected
No Signal Found
Wave Reflection
Signal waves reflect
off of Metal Surfaces
Constructive Phase
alignment creates false
positives
Solution: Continue to
monitor signal while
approaching source.
Scenario#2
Signal Found
Reflected Waves
Signal Present
Signal Lost
False Positive!
Destructive Phase
Constructive Phase
Signal Found
Metal Surface
The Motor
9FGHD Ferrite Series
ServoDisc Motor
Input voltage -12V to
+12V
Capable of 1.5 N-m
continuous torque
Motor Drivers
LMD18200t
Sign/Magnitude PWM Control
PWM Control Circuitry
Digital Compass Module
I2C 2-Wire Serial Interface
3.3v supply voltage
1/2 degree heading resolution
Firmware Included
I2C Module
I2C Communication
Compass Command Bytes
Getting compass data
Heading Mode: The heading output data will be the value in
tenths of degrees from zero to 3599 and provided in binary
format over the two bytes.
Signal Detection
Robot Signal Detection
Overview: This part of the robot will detect signals
within the GSM frequency-band that will then be
amplified by a Low Noise Amplifier, rectified into a
DC voltage, then finally interpreted by our
microcontrollers A/D converter.
This will be done by the following devices:
Tuned directional antenna
 RF signal amplifier and diode rectifier
 MSP430 A/D Converter

Tuned Directional Antenna
This component will give directional ordination to the
robot to pursue the signal.

A Yagi antenna will be used to hone in on the signal.

Antennas Specifications:
GSM: Uplink 890-915MHz and Downlink 935-960Mhz
PCS band: 1.7-1.99 GHz
Antenna Capability
Reverse-Polarity BNC-Plug
Adapter to Standard BNC-Plug
Signal Amplification
50 Ω Low Noise Amplifier
High output Gain
 Low noise figure
 Operates in the frequency band we require

Non-rectified RF Signal
Voice Call
*Volt scale is 100mV
*Signal is being boosted by LNA
Did someone say this was impossible?
Data Message
Phone 65 °
out of line
RF Signal Rectification Circuit
This simplified circuit will take the antenna’s RF
signal as an input and will output a voltage that is
proportional to the signal’s intensity.


LNA will boost signal gain
to a readable voltage level.
Diodes will rectify signal to
a DC voltage with minimum
losses.
Voltage Processing
Feed measured voltage into the micro-controller’s
A/D converter.
Have the microcontroller will only sample this
A/D at times of signal searching.
Store both RF intensity and robot degree of
direction data for a full revolution in on-board
RAM.
Find peak voltage within data and have robot
return to this recorded direction.
Microcontroller
Microcontroller
Prototype Board for MSP430-F1611





Multiple A/D converters, UART, and I2C peripherals
Expanded RAM to 10K bytes for greater storage capacity
PWM capabilities for motor control
Good tools and easy debugging
Cost effective solution of our application
Functional Block Diagram
AD Converter
We will be using the 12 Bit AD converter
peripheral.
The ADC will convert voltages into integers
between 0 and 4095 relative to the voltage levels.
 We will be using a reference voltage of 1.5V as
it gives us more resolution and we will not be
inputting anything higher than that.
ADC12
Module
IR Object Detection
Sharp GP2D12
Analog output voltage
distance from object
10cm to 80cm
Optimal Vcc 4.5-5.5 V
IR Sensor Voltage Output Curve
Voltage vs Distance
3
2.5
Voltage (V)
The IR sensors have a nonlinear output voltage curve
with respect to distance.
Range is from 10 to 80cm
with higher voltages
representing shorter
distances.
10cm-2.6v
80cm-.4V
>80cm-.25V
2
1.5
1
0.5
0
0
10
20
30
40
50
Distance (cm)
60
70
80
90
Home Base
If time permits we will still implement a home base.
Home Base will generate a signal to call robot home to:
 Recharge
 Be reprogrammed
Signal will be made by a function generator in antenna
frequency range.
More testing required to see what kind of information
antenna will give us.
Power Distribution
Power Distribution
Voltage Variations

5V



3.3 V


LCD Screen
IR Detectors
Microcontroller
12 V


Motor Drivers
LNA
Voltage Regulators


LM1117
Regulate to 5 V, 3.3 V
The Battery
2 BP7-12 12 V 7Ah
Batteries to power the
robot
5.94” x 2.56” x 3.98”
6 lbs.
Opto-isolators
HPCL-3150
Will be used for isolation and level shifting
for PWM, direction/brake signals
Disruption Handling
LCD Screen
Serial Enabled 16x2
LCD - Black on Green
10k Pot to adjust
contrast
D
N
G
D
N
G
G
C2-
C2+
2
3
2
3
R2out
T2in
t
u
o
2
D
N
D
X
R
D
N
G
TXD0
0
0
2
1
1
R1out
1
T1in
-
1
R1in
3
1
1
C1-
n
0
0
t
u
o
1
T
4
1
3
C10
V
2
C1+
1
D
N
G
+
5
1
Vcc
6
1
1
n
0
0
C11
3.3V
1
V
C12
S
9
T
4
n
0
5
n
0
6
0
1
6
C
0
1
C
1
n
0
0
1
Component_1
DVSS
D
G
P6.5/A5
4
AVSS
A
6
P6.2/A2
6
P6.1/A1
P6.0/A0
5
n
0
0
5X2
Header
0
1
9
P6.7/A7
F
R
6
5
3
8
7
D
N
6
5
4
3
IR5
2
1
P6.3/A3
C
P6.6/A6
C
C
V
C
V
P6.4/A4
2
6
1
3
6
IR4
2
4
6
_
P
3.3V
IR3
1
IR2
0
6
5
TMS
TDO/TDI
3
5
TDI
5
5
TCK
7
5
G
P5.3/UCLK1
4
D
N
P5.2/SOMI1
1
1
2
9
0
4
RST
P5.1/SIMO1
3
1
4
1
G
4
P5.0/STE1
4
JTAG
X2TOUT
5
X2TIN
5
P4.6/TB6
4
XOUT/TCLK
9
p
0
1
p
0
1
XIN
8
P4.3/TB3
MSP430F1611
3
D
N
G
P4.2/TB2
5
C
4
C
3
P4.1/TB1
3
P4.0/TB0
3
XTAL
P3.7/URXD1
3
2
1
P3.6/UTXD1
1
Q
G
3
P3.5/URXD0
2
1
3
XTAL
P3.4/UTXD0
G
3
P3.3/UCLK0
3
2
1
P3.2/SOMI0
2
Q
3
2
Header
6
P
P3.1/SIMO0
2
P3.0/STE0
G
2
D
N
G
reg
3V
P2.7/TA0
2
P2.6/ADCLK
1
D
N
G
2
P2.5/ROSC
Pol3
Cap
D
N
G
D
N
G
IR1
9
P5.7/TH
1
5
6
P5.6/ACLK
0
5
4
P5.5/SMCLK
9
4
5
P5.4/MCLK
5X2
Header
8
4
7
7
0
1
9
6
8
7
D
N
5
6
5
4
4
3
2
2
1
P4.7/TBCLK
3
4
3
5
_
P
3.3V
2
P4.5/TB5
1
4
P4.4/TB4
0
4
9
8
7
6
5X2
Header
5
D
N
4
0
1
9
0
D
X
R
3
8
7
D
N
TXD0
2
6
5
1
3
4
3
0
2
2
1
V_3GND
3.3V_3
9
1
D
N
3.3V
3
_
P
3.3V
8
7
F
p
0
0
u
1
6
D
3.3V
1
1
1
F
R
N
C13
3.3V
8
D
N
G
D
1
C14
6
2
Header
P_OUT
N
n
0
0
1
4
2
2
2
1
1
JTAG
3.3V
G
D
N
G
P_IN
G
T
R2in
7
.1u
.1u
.1u
S
8
C57
C56
C55
C54
.1u
.1u
.1u
.1u
C53
C52
C51
C50
.1u
3.3V
2
Header
5
2
C36
u
1
P2.4/CA1
C40
4
Header
4
2
K
0
1
K
0
1
C31
P2.3/CA0
3
2
7
R
6
R
u
1
4
P2.2/CAOUT
2
2
u
1
C34
u
1
u
1
D
N
G
3
P2.1/TACLK
1
2
IR1
C35
C33
C32
3
2
P2.0/ACLK
3.3V_3
0
2
1.5k
2
1
LED3
V_3GND
IR5
IR3
IR2
1.5k
1
R
1
P1.7/TA2
Comp
9
1
4
R
P1.6/TA1
VREF-
D
N
G
D
N
G
D
N
G
D
N
G
D
N
G
reg
5V
8
1
1
1
1.5k
1.5k
1.5k
P1.5/TA0
VREF+
7
1
7
5
R
3
R
2
R
P1.4/SMCLK
VEREF+
6
1
0
1
1
D
P1.3/TA2
5
1
4.5V
4.5V
4.5V
4.5V
4.5V
470u/16VDC
P1.2/TA1
D
N
G
4
1
P1.1/TA0
3
2
1
3
2
1
3
2
1
3
2
1
3
2
1
2
Header
3
1
P1.0/TACLK
RST/NMI
C38
2
1
8
5
2
1
U
1
V
2
1
3
Header
5
P
3
Header
4
P
3
Header
3
P
3
Header
2
P
3
Header
1
P
Batt_Pow
Schematic
PCB
Scheduling, Costs, and Labor
Updated Schedule
Separation of Tasks
Programming of Microcontroller – Travis
and Ben
PCB Design – Carey
Motor driver control – Bill and Ben
Antenna – Travis, Bill
LCD screen – Ben and Carey
Milestones
Milestone 1:Robot moves towards test
signal
Milestone 2:Programmable search
parameters, IR object detection integration,
home base construction complete
Expo:Robot and home base fully functional
Cost Estimations
Item
Yagi Antenna
Battery
IR Sensors
Motor drivers
Dev Board and Compass
LNA and connectors
E store(perf board and headers)
Total so far
Price
59.64
29.6
12.5
5
114.77
160
20
Quantity
1
1
3
4
1
1
1
Total
59.64
29.6
48.99
20
114.77
160
20
$453
PCB
MSP chip
LCD screen
IR sensors
Miscellaneous
66
20
25
12.5
100
2
1
1
2
1
132
20
25
25
100
Estimated Total
$755
Thank you!
??Questions??