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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