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?