EE 333301 Group 2

1
EE 3333-01 Group 2 Replacement
Transmitter/Receiver System
Shawn Higgins Austin Mullins John
Shefchik Advisor Dr. Mitra
2
Controller Design Options

• New design from op-amps and multiplexers
• PIC microcontrollers
• TI MSP430 microcontrollers

Austin Mullins
3
Controller Design Options
Austin Mullins
4
Microcontroller-based Design
Austin Mullins
5
ADC12 Calculations
Austin Mullins
6
Timer B Calculations
Austin Mullins
7
Converting ADC12 Data to PWM
Austin Mullins
8
MSP430 Control Test
Austin Mullins
9
Transmitter Control Flow Chart
Set up ADC12 and Timer A
Get ADC12 Values
Transmit Start Sequence
Transmit ADC12 Values
Austin Mullins
10
Transmitting Data
Load Data Byte
Get LSB 0 1
Send Low Frequency to PLL
Send High Frequency to PLL
Shift Right
Austin Mullins
11
Transmitter Software

• Based on UART Standard
• Programs MC145170-2 PLL IC to Generate FSK Signal
  Centered at 75 MHz

UART Paradigm
Start Bit
8-bit Character LSB First
Parity Bit
Stop Bit
Austin Mullins
12
Transmitter Software
Example of MSP430 Output using hex 0064 as
transmit(LOW).
Austin Mullins
13
Receiver Software
Set Up Timer B for PWM Control
Set up PLL for Local Oscillator Control
Shift Start Byte Into RX0BUF Register
Check Start Byte
Shift ADC12 Data Into RX0BUF Register
Convert ADC12 Data Into PWM Duty Cycles
Store Value in Duty Cycle Registers
Austin Mullins
14
Software Tests

• Transmitter Software
• Receiver Software
• PLL Control
• Transmitter/Receiver Combined

Austin Mullins
15
Transmitter Layout
Austin Mullins
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Transmitter Design
MAX2606
Output to Amplifier
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
17
Transmitter Design
Output to Amplifier
MAX2606
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
18
PLL Testing w/ MSP430
REF OUT - Power up (1.25 MHz)
RE FOUT Program (.625 MHz)
OSC IN (10 MHz)
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Transmitter Design
Output to Amplifier
MAX2606
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
20
VCO Tests
Approximate Tuning Range 70 80 MHz
Tuning Voltage 0.970 V
Tuning Sensitivity 4.318 MHz /
Volt
John Shefchik
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Transmitter Design
Output to Amplifier
MAX2606
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
22
Low Pass Filter
PDOUT
To VCO
308.272K
187.537K
2.058 kHz
205Hz
1000pF
628.3185 rad/s
2.752e7 rad/s/V
N 15000
John Shefchik
23
Transmitter Design
Output to Amplifier
MAX2606
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
24
PLL Tests
Using Current Low Pass Filter Design Cutoff
Frequency 500Hz Desired Frequency 75.0000MHz
FR
FV
LD
PDOUT
25
PLL Tests
Using Current Low Pass Filter Design Cutoff
Frequency 200Hz Desired Frequency 75.0000MHz
FR
FV
LD
PDOUT
26
Transmitter Design
Output to Amplifier
MAX2606
VCO
Reference Oscillator
MC145170
PLL
MSP430
Low Pass Filter
John Shefchik
27
Transmitter Output Results
28
Amplifier Design
75Mhz
60Mhz
29
Receiver Block Diagram
XTAL
Input RF
MAX2605
Voltage Controlled Oscillator
Phase Lock Loop
MC145170
Recovered Message Signal to MSP 430
MAX436
75MHz
455KHz
Quadrature Detector
Amp
Voltage Comparator
Tuned RF Amp
Mixer
AD608
Shawn Higgins
30
Maxim MAX436 Transconductance Amplifier

• Produces output current
• Proportional to differential input voltage
• Inversely proportional to transconductance
  impedance
• Current then multiplied by gain factor K and load
  impedance ZL to get Vout
• The impedance of the transconductance network is
  at a minimum at the resonant frequency

Input Voltage .3V P-P Output Voltage 1.6V
P-P _at_75MHz
Shawn Higgins
31
Analog Devices AD608 Mixer
IF -16dBm _at_75 MHz RF -20dBm _at_ 75.455MHz Output
-46.4dBm _at_ 455kHz
Output if transmitting on next channel

• IF -16dBm _at_75 MHz
• RF -8dBm _at_ 75.455MHz
• Output -29.9dBm _at_ 455kHz

Shawn Higgins
32
Amplifier
Input Voltage .3V P-P Output Voltage 1.9V
P-P _at_455kHz
Input -29.9dBm Output -2.6dBm _at_455kHz
Shawn Higgins
33
Quadrature Demodulator

• The phase shift network
• LC tank circuit
• Gives a frequency-sensitive phase shift at the
  center frequency
• Phase detector compares the phase of the IF
  signal phase shifted signal
• Produce PWM relative to phase coherence
• Output of phase detector is low pass filtered,
  which results in a DC level that changes as the
  input frequency changes
• Message signal recovered
• Intermediate freq. blocked
• Output of LPF and sent to voltage comparator

Converts IF sin wave to square wave of same freq.
Phase Shift Network
Phase Detector
Low Pass Filter
Shawn Higgins
34
Test Results
Inputs to Phase Detector
400 Hz Demodulated
AND Gate Output With Mixer, Amp, Demodulator
Intergraded
1 KHz Demodulated
Shawn Higgins
35
Quadrature Detector Layout
Shawn Higgins
36
Final Budget
37
Final Gantt Chart
38
References

• Best Robotics Incorporated, http//www.ee.ttu.ed
  u/wt-best/tether/FieldX1.html (Sep 2004)
• Futaba SkySport 4VF, http//www.futaba-rc.com/ra
  dios/futj61.html (Sep 2004)
• The Model Electronics Company,
  http//www.omegaco.demon.co.uk/mechome.htm (Sep
  2004)
• Basic Communication Electronics. Hudson, Jack and
  Luecke, Jerry. Lincolnwood, Illinois. Master
  Publishing, Inc 1999.
• The ARRL Handbook. The National Assoication for
  Ameteur Radio. Newington, CT. The American Radio
  Relay League, Inc 2001.
• MSP430 Data Sheet. http//www.ti.com (Sept 2004)
• MC145170 Data Sheet. http//www.freescale.com
  (Sept 2004)
• MAX2606 Data Sheet. http//www.maxim.com (Oct
  2004)
• MAX2605 Data Sheet. http//www.maxim.com (Oct
  2004)
• AD608 Data Sheet. http//www.analog.com (Oct
  2004)
• 74VHCT08A Data Sheet. http//www.fairchildsemi.com
  (Oct 2004)