UVM CricketSat Assembly Manual

1
UVM CricketSat Assembly Manual
2
Getting Started

• Make a hard copy print out of the following page
• It will help you identify the proper components
• Place the components on top of the matching
  picture on the sheet
• Generally, the lowest profile components are
  added to the board first
• Many components need to be properly orientated
• Pay close attention to instructions concerning
  the proper placement of those components
• Use safety glasses while assembling the
  CricketSat. Hot solder and flying leads can
  injure your eyes.

3
R4 100 Ohm
C1
C3
C2
C4
C5
C6
Negative White Band
Brown-Black-Brown-Gold
R2 3300 Ohm
0.1 micro-Farad Capacitors
Orange-Orange-Red-Gold
Black Band
D2 - Diode

-

-

-

-
R3 680 Ohm
Longer Lead
Notch
47 micro-Farad Electrolytic Capacitors
Dimple
Blue-Gray-Brown-Gold
Pin 1
8765
1234
D1
U3 RF Transmitter
DIP Socket
U1 555 Timer IC
R1
U2
SW1
Flat Side Up
Longer Lead
1 2 3
Pins
1 2 3 4
Pins
-
10K Ohm Thermistor

5-Volt Regulator
On/Off Switch
Light Emitting Diode (LED)
B1 9-Volt Battery
-
Printed Circuit Board (PCB)

Red Lead is Positive
Battery Snap Connector
Antenna Wires
-

4
Printed Circuit Board

• Metal layers - conductors
• Front and back sides
• Epoxy board - insulator
• Traces provide the wiring
• Via holes - 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

5
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 Hersheys Kiss shape

• Snipping leads
• Flying leads may damage eyes!
• Hold lead while cutting or point downward

Snip just above solder joint
6
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...
7
Small Capacitors and Battery Clip
Route wire down through these center holes
Solder wire to these outer holes
Top View

• Install Battery Clip
• Feed 2 inches of wire down through strain relief
  holes, from top side of board
• Push bare wire ends completely up through solder
  pad holes from bottom side of board
• Pull excess wire tight. Should look like this
• Solder connection on top side of the board
• Trim excess wire on top of board

Red
Black -
Bottom View
Install Capacitors C4, C5, C6 0.1 uF
Clip leads...
No Bare Wire Allowed
8
DIP Socket

• Align socket with white outline provided on board
• Place the notch up, towards C4
• On/Off Switch outline for next step...

• Use the vise alligator clip to hold the socket 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

9
On/Off Switch
Solder all eight pins of the switch

• Use the vise alligator clip to hold the switch in
  place or press flat against table surface while
  soldering
• Make sure that switch is flat to the circuit
  board and that all the pins emerge from the
  backside of the board before soldering in place

10
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...
11
Install the Antenna Wires

• There are four antenna holes
• Wires are soldered to the outer two holes, and
  pass through the outer two
• Strip ½ of insulation from end of wires
• Insert a bare wire end from the bottom side of
  the board through one of the two outer
  white-circled 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
• 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 inner
  strain relief holes from the bottom side of the
  board
• Pull tight and snip excess bare wire on top of
  board

Top View
No bare wires through the strain relief holes
Bottom View
12
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.

13
Finally, the Thermistor

• Stands up above other circuits
• Use the black plastic insulation that you
  stripped from your antenna wires in an earlier
  step
• 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
14
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

15
Live Test

• Connect the 9-Volt battery
• Observe the LED, it should be flashing around 1-2
  Hertz (times per second)
• 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 on your successful assembly!
16
Primary Features
Prototype Development Area
555 Timer IC
5-Volt Regulator IC
Timing Capacitor
On/Off Switch
Dipole Antenna
9-Volt Battery Leads
Thermistor
Test Points
RF Transmitter Module
Timing Resistor
Flashing LED
17
Secondary Features
Noise Decoupling Capacitor
Protection Diode (Reverse Battery Connection)
Noise Decoupling Capacitors
Current Limiting Resistor (LED)
Noise Decoupling Capacitor
Output Jack
Series Isolation Resistor
18
(No Transcript)