AEM 1905: Spaceflight with Ballooning University of Minnesota Building a NearSys BalloonSat Easy Flight Computer for a Near-Space Payload AEM 1905: Spaceflight with Ballooning University of Minnesota

BalloonSat Easy kit and instructions

Parts in BalloonSat Easy kit

Printed Circuit Board (PCB)

Resistors, to be numbered R1 – R8

Diode – polarity indicated by the stripe

9-volt battery snap for main power

AAA battery pack for servo power

Wires for switches, camera, etc.

Toggle switches for main power and servo

Heat-shrink tubing (AKA shrink-wrap)

IC (only one shown) and two IC sockets

Capacitor – polarized; longer lead is positive

5-volt voltage regulator

Main power indicator LED; flat edge is the negative lead

Reed relay to fire hot-wired camera (in any)

3- and 6-pin headers, including the Programming Header, the Commit Header, and the (female) receptacle

Shorting plug (AKA pull-before-flight pin) which goes over Commit Header

Identify which resistors are which then solder in R1 through R8 in exact locations. R8 = 330 ohms (missing from instructions).

Solder in diode – use strip for polarity

Use Helping Hands to hold Commit Header in place for soldering

Commit Header now soldered in place (sticks off edge of the PCB)

Solder in 9-volt battery snap using the strain relief holes in the PCB

Do the same with the servo battery pack

Cut long wire into 6 equal pieces then strip one end of each to ¼ inch length

Leave other end of two unstripped (for camera – unimplemented) but strip the others ¾ inch and twist to avoid fraying

Solder in camera wires, using strain relief

Solder in 4 switch wires, using strain relief

Slide on shrink-wrap before proceeding

Hook one pair of switch wires through the center and one side post of each switch

Solder wires to pins, minimizing diameter

Slide shrink-wrap over solder joints once both wires have been soldered

Shrink with heat gun – complete 2 switches

Insert IC sockets in PCB – watch notches

Solder in the capacitor – watch polarity

Insert voltage regulator – watch polarity

Avoid solder bridges on closely-spaced pins of the voltage regulator

Insert power indicator LED; positive lead (non-flat edge) goes next to the letter “A”

Insert REED relay – only goes in one way

Insert 3-pin male Programming Header and 3-pin male Servo Header (short ends through the PCB) without soldering yet. Insert the 6-pin female receptacle (it may be too tight for all the pieces to fit flush).

Shave or sand off receptacle if need be so it fits next to Servo Header. Once all fit flush to the PCB, solder pieces in place.

BalloonSat Easy Flight computer, without chips, ready for testing