Transcript Building a NearSys BalloonSat Easy Flight Computer for a

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