Transcript CSatAssmbly - University of Vermont

CricketSat Assembly Manual
CricketSat Background
• Developed at Stanford
University
– Space Systems
Development Laboratory
• Part of the NASA student
satellite program
– Teach fundamentals of
space hardware
development
– Space Grant Fellowship
Program
• Funded support
• Vermont Space Grant
Consortium (VSGC)
– UVM campus
Student Satellite Programs
• CricketSat
– Lowest cost - disposable
– Live telemetry
• BalloonSat
– Larger balloon
– Expensive instruments
– GPS tracking system
• CanSat
– Dropped by parachute from plane
or rocket
– Many instruments
– Live telemetry
– Test bed for CubeSat
• CubeSat
– Earth-orbit satellite
Getting Started
Your Parts Kit
• Your kit contains parts for
two CricketSat sensors
• They are all mixed
together in the same bag
• The second unit will not
have an RF transmitter or
antenna
• The second unit may be
used for your final project
Prepare for Assembly
• Make a hard copy print
out of the following page
• It will help you identify
the proper components
• Place the components
with the matching
picture on the sheet
• T.A. sign off
TA:
C1
C2
R4: 100 Ohm
C3
C4
C5
C6
Negative
White
Band
Brown-Black-Brown-Gold
R2: 3300 Ohm
0.1 micro-Farad Capacitors
Black Band
+
-
+
-
+
Longer Lead
+
Notch
47 micro-Farad Electrolytic Capacitors
Pin 1
U3: RF Transmitter
Orange-Orange-Red-Gold
D2 - Diode
R3: 680 Ohm
Dimple
1
2
3
4
DIP
Socket
Blue-Gray-Brown-Gold
8
7
6
5
U1: 555
Timer
IC
D1
U2
Flat Side
Up
Pins: 1 2 3
Pins: 1 2 3 4
5-Volt
Regulator
B1: 9-Volt Battery
R1
10K Ohm
Thermistor
Printed Circuit Board (PCB)
+
Red Lead is Positive
Battery Snap Connector
Antenna Wires
-
+
Longer
Lead
+
Light
Emitting
Diode (LED)
Printed Circuit Board
• Metal layers - conductors
–
–
–
–
Front and back sides
Epoxy board - insulator
Traces provide the wiring
Vias - connect the front and
back metal layers
• Front side of board
– Components on this side
– White silkscreen layer
• Component outlines
• Reference designators
– Green solder mask layer
• Insulates exposed metal
• Back side of board
– Solder on this side
Assembly Techniques
• Inserting Devices
– Bend leads if necessary to ease
insertion into board
– While pressing component to
board, bend leads at an angle
– This will hold components in
place while soldering
– Just 4 or 5 components at a time
45 degree angle is best
Bend lead close to board
• Soldering
– Use enough heat
– A shiny Hershey’s Kiss shape
• Snipping leads
– Flying leads may damage eyes!
– Hold lead while cutting or point
downward
Snip just above solder joint
Resistors and Diode First
D2 - Orange Diode
(Black Band to the Left)
R4 - 100 Ohms
R3 - 680 Ohms
R2 - 3300 Ohms
Clip leads after this step...
Small Capacitors and Battery Clip
Solder wire to
these holes
Route wire down through
these holes
Install Battery Clip
+ RED
- BLACK
Top View
Bottom View
•Push bare wire ends
completely up through
solder pad holes from
bottom side of board
•Pull excess wire tight.
Should look like this…
Install Capacitors
C4, C5, C6
•Solder connection on
top side of the board
0.1 uF
Clip leads...
•Feed 2 inches of wire
down through strain
relief holes, from top side
of board
No bare wire allowed!
•Trim excess wire from
connection
DIP Socket
•Align socket with white
outline provided on board
•Place the notch up,
towards C4.
•Use the vise alligator clip to hold in place or press flat
against table surface while soldering
•Make sure that socket is flat to the circuit board and
that all the pins emerge from the backside of the board
before soldering in place
Installing the Taller Parts
U2 - Voltage Regulator
Push only half-way into board
Install these Parts...
•C1, C2, C3 -Polarized
•White band (-) to outside of
board
•U2 - Orientation
•Flat side left, towards C3
•Push only half-way into board
•D1 LED -Polarized
•Longer lead (+), next to socket
Make sure capacitors are mounted
close to board surface to minimize
movement
Clip leads...
Install the Antenna
•There are four antenna holes
•Wires are soldered to the center two
holes, and pass through the outer two
•Insert a bare wire end from the bottom
side of the board through one of the two
center marked antenna holes
•Rest it on a table surface as shown left
•The weight of the board should insure that
all of the bare wire extends through the
top of the board
No bare
wires
through the
strain relief
holes
•In this position, solder the connection on
the top of the board as shown
•Repeat for the other wire
•Feed the free ends of the wires through
the strain relief holes
•Pull tight to set as shown
•Snip excess bare wire on top of board
Transmitter and Timer IC
Transmitter Module
•Install the transmitter as shown to the left
•Metal can faces towards antenna
•Make sure the module is soldered close to
the board to minimize movement
Clip your leads...
555 Timer IC
•Locate Pin 1 on the IC, marked with a
“dot”
•This end of the IC goes next to C4
•Straighten pins if necessary and press into
socket
•If pins bend while inserting into socket,
remove IC and straighten pins.
Finally, the Thermistor
•Stands up above other circuits
•Search parts bag for two pieces of black
insulation
•Slide insulation up to the body of the
thermistor in order to insulate the leads
•Insulation prevents “short circuits” to
other exposed metal leads
Solder at location R1
on the circuit board
Short Circuit Test
•We want to make sure that there are no
short circuits on the board
•Performed before connecting the battery
for the first time
•Set the meter to the OHMS setting
•Touch the meter leads to the battery
connector as shown
•Meter should indicate an open circuit
•Reverse the test leads and measure again
•Should be an open circuit reading again
•Contact your T.A. before
connecting the battery
Live Test
•Connect the 9-Volt battery
•Observe the LED, it should be flashing
around 1-2 Hertz
•RF Test: Use a UHF radio receiver
tuned near 434 MHz to hear pulses
•Optional: Measure the voltage on the
V+ and 5V test points
Congratulations!
TA: Sign-off on Parts Sheet
Primary Features
Prototype
Development Timing
Area
Capacitor
555
Timer
IC
5-Volt
Regulator
IC
9-Volt
Battery
Leads
Dipole
Antenna
RF
Transmitter
Module
Test
Points
Flashing
LED
Thermistor
Timing
Resistor
Secondary Features
Noise
Decoupling
Capacitor
Output
Jack
Series
Isolation
Resistor
Protection Diode
(Reverse Battery
Connection)
Current
Limiting
Resistor
(LED)
Noise
Decoupling
Capacitors
Noise
Decoupling
Capacitor