AubieSat-I
Final ReviewApril 23 2008
S pring 2008 Goals
• Build and te s t a table -top v e rs ion of Aubie S at-I–Build compone nts of all sub-sys te ms and te s t
the m
–Build and te s t indiv idual sub-sys te ms
–Inte g rate and te s t full s ys te m
• Finish building g round s tation and be able to re ce iv e sate llite s ignals
S ys te m Eng ine e ring
S ys te m Eng ine e ring
EPS
CDH
COMM
PLYD
GND Station
5v
5v,3.3v,3.7v, Data lines
5v
CNTRL & Data Lines
S ys te ms Eng ine e ring
Accomplishme nts
•ICD and othe r inte rface docume nts cre ate d and update d
•Pin-out diag ram comple te d.
•Main board te mplate done .
•Inte rfacing be twe e n s y s te ms s tarte d
•Te s ting proce dure for AS -1 s y s te m done .
S ys te ms Eng ine e ring• 80 indiv idual line s available .
• 43 indiv idual line s ne e de d.– Extra pins will be use d to double up highe r curre nt line s and re plicate the data line s .
40 Pin Header
40 Pin Header
GND
GND
3.3V5v 3.7v
SP
I
I2C
US
AR
T
Control Lines
Control Lines
40 Pin Headers (ORCAD)
Standard PCB
Pay loadEnd of S e me s te r S tatus Re port
Pay load
• Goals–Came ra Module
–High S pe e d Data Line
–Multiple I2C inte rface
–Exte rnal Me mory
–Magne tome te r
–Fight S ong
–S e lf Powe r Re gulation
–S cie nce Miss ion
Pay load• A Bayer filter mosaic is a color filter array
• By integrating this array we can create pixels.
•The array Pattern is
•2 Green cells per pixel
•1 Blue cells per pixel
•1 Red cells per pixel
Pay load
Pay load
Pay load• Magne tome te r
–Hone ywe ll HMC1052L
–2 axis Magne tome te r
–S e ns itiv ity :• 160 micro-gauss incre me nts
–Output:• Analog Voltage s ignal
(+Vdd, 0)
Pay load•Powe r Control
Module s
Payload’s MainMicrocontroller
Camera’sEXT
CLOCKMemory
SecondaryReceiver
Power LineControl Line
VDD
C&DH
Pay load
• Comple te d– Magne tome te r
– High S pe e d Clock Line
– Dual I2C Line s• 1x Mas te r
• 1x S lave
– Exte rnal Me mory
– Fight S ong (for De mo)
– Eme rge ncy S hutdown
– S ubsys te m’s indiv idual powe r control.
• S umme r Goals– Finish Image Proce ss ing
– Inte rface high spe e d Bus
– Me dia Formats
– Colle ct image s on de mand
– Inte g rate into one sy s te m
– S ys te m Le ve l Te s ting
C&DH
Jaeho JeonMac ChampionWilliam Fiser
Nathan ShaferHung NguyenAaron ScottGurjot Singh
C&DH Block Diagram
Accomplishments this Semester
• Successfully got uC/OSII Real-time Operating System running on the microcontroller with task-based execution
• Successfully implemented the following interfaces: I2C, SPI, and serial interface
• Successfully read and write to flash memory over SPI, read data from ADC’s over I2C, and triggered the antenna switch relay.
• Successfully implemented AX.25 protocol.
Software Results
Wrote software to:
• Read from multiple ADC’s (Analog to Digital Converters)
over I2C (Inter-Integrated Circuit) Interface
• Switch antenna relays
• Read and write data into flash memory via SPI (Serial
Peripheral Interface)
• Send and receive data packets using AX.25 protocol.
Future Goals
C & DH needs to continue hardware integration with other
subsystems
We also need to write a consolidated demonstration
program using all available communication protocols,
demonstrating all individually completed functions
EPSBrad Dutton
S te phan He nning
Grant Moore
Ge orge S tarr
EPS
Charger
Solar
CellsSatellite
Battery
HSS
RBFDeploy
EPS
•Allows for inte rnal source switching–Automatic trans ition be twe e n S .C. and Batt.
•Batt. not use d unle s s s ys te m load is large r the n what the S .C. can supply .
•Batt. use d whe n ne e de d, othe rwise ke pt fully charge d.
•Ground support charge port–Isolated from rest of system
•Doesn’t need to be a part of the Kill/RBF switch circuit.
•2.5W available to the satellite in this state.
MAX8677c Charger IC
EPS•Re dundant re gulators prov ide insurance
–Prov ide two bas ic functions•Ove rall re dundancy•Additional powe r trans fe r
–Re gulators are not pushe d as hard as both re gulators supply the same load in normal conditions . Diode s prov ide source isolation and prote ction agains t shorte d failure s .
•LTC3533–Stabilizes SC output
•Provides clean power to the MAX8677c•MAX8677c requires 3.9v<input<6.5v
–Solar Cell output will vary over period of SC rotation.
MAX1705, MAX1709, LTC3533
Power Budget Summary
Orbit Period 98.8 minMaximum Eclipse Time 35.3 minAverage Comm window 12 minNumber of Comm windows per day 4 /dayP(total avg) 2.41 WEnergy Gained in One Orbit 9171 JNormalized Average Energy per orbit 92.8 J/minTotal Energy Storage 45288 JStandard Orbit Net Energy 2790 Joules# Standard Orbits to Charge 16.2 orbitsComm Orbit Net Energy -4734 Joules# Comm Orbits to Discharge 9.6 orbits
Assumed 80% power conversion efficiency + 15% contingency
S C array PS PICE mode l
24 hr Energy Graph
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
1 36 7110614
117
621
124
628
131
635
138
642
145
649
152
656
159
663
166
670
173
677
180
684
187
691
194
698
110
1610
5110
8611
2111
5611
9112
2612
6112
9613
3113
6614
0114
36Minutes
Jou
les S
tore
d
All Comm Orbits
Distributed Comm Orbits 5
Consecucutive Comm Orbits 5
EPS• Accomplishme nts
–3.3v re gulators working• Output me asure d unde r load, compare d to no load
–S witching fre que ncie s on par with e xpe cte d re sults
–Charge rs working• S ource switching /load ass is t works as e xpe cte d• The rmal s tuff down works• Paralle l charg ing works
•Problems–5v regulators
•Cannot handle loads over 500mA
•Switching frequency of output measured. –Found to be exceeding the 680kHz rating under no load
conditions
•Causal analysis not completed.
•Trouble shoot 5v re gs
•Prototype S C re gulators
•Inte grate RBF/De ployme nt switche s
•Long te rm te s t to v e rify s y s te m ope ration.
EPSTo Be Done:
Communications S ubsys te m(Primary Te am)
Je re my EcholsJosh JacobsJosh MartinBe th White
Block Diagram of Communications
Primary S ubsys te m
Accomplishme nts
• Establish communication be twe e n the VX-2R and ground s tation
• Build and te s t the ante nna switching matrix
• Build and te s t powe r re lay for the VX-2R• Build and te s t a table top prototype of the
subsys te m • Inte grate with othe r subsys te ms
–Inte g ration proce ss has be gun
Communication with Ground S tation
• Able to succe ss fully communicate with g round s tation
• Re place d old software to communicate us ing AX-25 format– Now us ing AGW
Packe t Eng ine
Ante nna S witching Matrix
Primary Transceiver
Secondary Receiver
HF3 93 Relay
HF3 93 Relay
Ante nna S witching Matrix - De s ign
• Axicom HF3 93 Re lays–3ms pulse of at
le as t 3.75Vdc to switch re lay
–50 ohm impe dance
–Low cos t
Ante nna S witching Matrix - De s ign
• Micros trip transmiss ion line s–RT/duroid 5870 one -s ide d high fre que ncy laminate
• Thickne ss : 31 mils• Die le ctric cons tant: 2.33
–Must achie v e 50 ohm characte ris tic impe dance• Width of transmiss ion line s : 2.34mm
• Pins of re lays conne cte d to transmiss ion line s with wire s–Will this cause re fle ctions?–No! The wire s are fractional wave le ng th (@ 450MHz ,
wave le ng th=0.667m.)
Ante nna S witching Matrix - De s ign
Ante nna S witching Matrix -Te s ting
• Do line s have a 50 ohm characte ris tic impe dance ?
• Doe s the matrix switch be twe e n the two ante nnas?
• Doe s the matrix suffic ie ntly atte nuate the s ignals?
Connection Ant 1 to 2nd Receiver
Ant 1 to Primary Receiver
Ant 2 to 2nd Receiver
Ant 2 to Primary Receiver
S21 (dB) when
Switch Closed -1.78 -3.67 -1.78 -3.47
S21 (dB) when
Switch Open -34.9 -24.4 -23 -40.4
Powe r Re lay
• Controlle d by both C&DH and se condary COMM
• An inte rface to turn the VX-2R on and off whe n ne ce ssary
• Compone nts – J-K Flip Flop–NAND gate–Inve rte r–HEXFET Powe r MOS FET
Powe r Re lay S che matic
Powe r Re lay De tails
• A clock pulse from C&DH or re moval of 5V s ignal from se condary COMM will shut off the VX-2R
• Anothe r c lock pulse or 5V s ignal applie d again will turn it back on
• 5V s ignal applie d to the gate of the MOS FET e ffe ctiv e ly ope ns and c lose s a switch to control the powe r to VX-2R
Future Work to be Comple te d
•Build ne w v e rs ions of the following compone nts to fly on the sate llite :–Ante nna switching matrix
–Powe r re lay
•Comple te inte g ration with ne ce ssary subsys te ms
•De te rmine the be s t layout for all compone nts to succe ss fully fit in the sate llite
Communication Te amS e condary Re ce iv e r
Andre w WoodAmanda Bowman
Kris Pe e ble sJame s Curtis
Ove rv ie w
Progre ss this S e me s te r•Prototype
–Table -top v e rs ion
•Inte gration–Ground S tation
–Primary Comm.
•PCB board layout.
DecoderSquelchCircuitReceiverLNA
Prototype Hardware
•Re ce iv e r–Chip
•Me le xis TH71102
–De ve lopme nt Board•Me le xis EVB71102
–De code r•Holte k HT12D
438 MHz
418 MHz
ReceiverAttenuator
DecoderEncoder
RF Switch
Network Analyzer / Frequency Generator
Te s t Re sultsInput (Switches) Output (LEDs)
Inte g ration Re sults
•Ground S tation–Able to re ce iv e and de code commands
wire le ss ly at short dis tance s
–Able to display re ce iv e d commands us ing (LEDs)
•Primary Comm.–Able to shut down primary re ce iv e r to me e t
FCC re quire me nts
S oftware Re sults•No software involv e d!
Future Work
•Print board layout
•Cre ate Ge rbe r and drill file
•S olde r parts onto board
•Ve rify corre ct routing and place me nt
Me chanical S ys te ms
Ke v in Carpe nte r
Kris Pe e ble s
Andre w Long
S cott Jame s
Progre ss
• Change s in e xte rnal s tructure–S olar ce ll orie ntation
–S olar ce ll de pre ss ion
–RBF pin / comm. port
Progre ss• Changes in internal
structure–Custom board
spacing / pin headers–Battery / magnet
mounting–Top plate mass
reduction
Hardware• S tructure
– Aluminum 7076• 6 e xte rnal pie ce s• 24 space rs• 2 batte ry / 2
magne t mounts
– Fas te ne rs• 4 – 10-24 100mm
long bolts• 16 - 6-32 machine
scre ws
Hardware
• Ante nna De ployme nt–Ante nna
• Nitinol Wire
–Hinge
–He ating Ele me nt• Nichrome Wire
–Fishing line
–Guide s
–S pring
Hardware
•Misce llane ous Parts–De ployme nt S witche s
–De ployme nt S prings
–Pin He ade rs
–Isolation S pring
Re sults• S pace re quire me nts (z -axis )
6 mmSpacer 3
98.5Total
1.5 mmBottom Plate
8 mmBottom Bolt Stub
16 mmSpacer 6
18 mmSpacer 5
10 mmSpacer 4
8 mmSpacer 2
8 mmSpacer 1
10.5 mm7 PCB x 1.5mm
6 mm2 Chassis Spring x 3mm
5 mmTop Bolt Stub
1.5 mmTop Plate
Height (mm)Component Name
Re sults
•The rmal Mode ling–Inte rnal
•Conduction
•Radiation
–Exte rnal•Radiation
Re sults• Improve me nts
–Contact Re s is tance
–S hape Factor
• Proble m Are as–Transce iv e r
• 5W
• Low e ffic ie ncy
–TNC-X• 2.5W
Re sults• Exte rnal
–Highly de pe nde nt on rotation
–Radiation S ource s• S un
• Albe do
Future Work
• Change s to s tructure–De ployme nt switche s
–Bolt / space r se le ction
–Add hys te rs is mate rial
–Te s t pin he ade rs
–Change PCB dime ns ions
–Add isolation spring
• Improve the rmal analy s is
• Be g in v ibration analy s is
• Build 2nd s tructural prototype
• The rmal / Vibration Te s ting
Ground S tation
Byron Caudle
Eric Grime s
Dav id S pe ck
Ground S tation
Computer (connected viaseria ports)
Tranceiver,ICOM 910
Audio outPTT
Audio in
Levelconverter for
frequencycontrol link
Roof Equipment
AntennaSwitch
DC powersupply(MFJ 25amp) 70cm beam antenna
Ground Station Equipment
Rotator -twin axis,Yaesu G-5500Rotator
Controler(YaesuG-5500)
Rotator ControlInterface(YaesuGS-232A)
Secondarycomm. sys.FSK RFgenerator
Serialencodedcommands
FSK - RF output@ low power F
SK
- RF
output
@ high po
wer
12VDC
12VDC
12VDCFrequencyControl In
Serial data stream
Rotator Power
supply and
Rotator signal
wires
RF RF RF
RF
VG
A s
igna
l
2m beam antenna
12-wire
bundle
Serial Data
Stream
(Bidirectional)
TNC(KANTRONICSKPC3+), KISSmode
Serial data stream
Secondarycomm syscommand boxand HoltekHT112Eencoder
Secondarycomm.sys. RFamplifier
ReceiverPre-Amp
VideoCamera
IP protocol system
Television
S e condary Command Control
• The ory of ope ration– Four paralle l data bits re pre se nting a g iv e n command
are se rializ e d and output v ia a PWM s ignal.– The PWM s ignal fe e ds the FM modulation port on an
FM ge ne rator, re sulting in an FS K s ignal.– The FS K s ignal is amplifie d and transmitte d to AS -1.
• Compone nts– Encode r – ope rational– Ve rification of e ncode r through de code r – ope rational– Control Box – asse mble d and ope rational– FS K-RF ge ne rator – asse mble d and ope rational– High-powe r RF amplifie r – to be de te rmine at a late r date .
S e condary Comm FS K sys te m
Othe r Ground S tation Ite ms
•Re ce iv e r pre -amplifie r – purchase d and ins talle d.
•Ne w GS compute r – asse mble d and ope rational.
•GS room arrange me nt – c le anup and organization large ly comple te d.
•Te le v is ion – mounte d and ope rational.
Ground S tation S oftware• Goals to April 23:
–De ve lop software to de mons trate data-display ing and command-se nding capabilitie s .
–Adapt programs to actual data formats–Docume nt all accomplishme nts and comme nt all
programs .
• Accomplishme nts–Graphical Use r Inte rface cons tructe d that allows
use r to se nd commands and display data for de mons tration purpose s .
Read Datafrom Text File
DetermineProper Value
Write Valueto NextColumn
Write Valueto “Latest”Column
Write Codeto Text File
DetermineCommand
Code
DetermineCommandNumber
InitializeSpreadsheet
xlssetup.m
SelectionChangeFcn
totext.m
datadisplay.m
Any Que s tions?