Lepus-A

Commissioned:  14-APR-2016
Status:  Missing in Action
Missions: Icarus I

Design Concepts and Considerations

The Lepus-A is the first Lepus Module designed and built for the Icarus Mission, and stayed within all tolerance allowances in the specifications.

The Trackuino Shield project only included two temperature sensors.  One was to take internal payload temperature readings, and the other connects to added wires to the terminal block for taking external temperature readings.  I added the data logger, barometric pressure, and humidity sensors to the project to gather additional data.

Components List

Envelope: 1200g Latex Balloon from High Altitude Science
I
 built the inflation system by taking a threaded gas nipple that fit the end of the hose from the regulator by drilling a slightly smaller hole int he end of a 1" PVC cap (that inserts straight into a 1" PVC elbow).  I used a 100W Weller Solder Gun to heat up the end of the nipple so that it "melted" threads into the hole I drilled.  The gap between the lip of the cap and the elbow gave a convenient spot to hang a weight to ensure proper inflation.

Parachute:  5' Parachute from The Rocketman

Payload Hull:  2" thick polystyrene box donated by Dr. Mark Smithers DVM at the Cass County Veterinary Clinic

Avionics:

Avionics Controller: Trackuino v2.2 Shield

Transmitter Module: Radiometrix HX1-144.390-3 Narrow Band FM Transmitter from LEMOS International

Sparkfun Components List:
Component Description...
Microprocessor Sparkfun Redboard (Arduino Uno clone)
Data Logger Sparkfun OpenLog
GPS Sparkfun Venus GPS with SMA connector
Humidity Sensor SparkFun Humidity and Temperature Sensor Breakout - HTU21D
Barometric Pressure Sensor SparkFun Barometric Sensor Breakout - T5403
Alarm Buzzer Piezo Speaker - PC Mount 12mm 2.048kHz

The following parts consists, primarily, of SMDs (surface-mount devices).  I wasn't equipped or skilled enough to solder the ICs to the board (and I barely accomplished soldering the resistors), so I took the board and components to John Avey KD5ZCS at Avey uTech Services, LLC in Queen City to solder the components for me.

Digi-Key Components List:
*** Digi-Key Shared Shopping Cart with the following components are available >>> here <<< ***
Part No. Qty. Ref Description...
CR1206-FX-6811ELFCT-ND 1 R1 6.81k Ohm ±1% 0.25W, 1/4W Surface Mount Resistor Thick Film ±100ppm/°C 1206
CR1206-FX-2211ELFCT-ND 1 R2 2.21k Ohm ±1% 0.25W, 1/4W Surface Mount Resistor Thick Film ±100ppm/°C 1206
CR1206-FX-1001ELFCT-ND 1 R3 1k Ohm ±1% 0.25W, 1/4W Surface Mount Resistor Thick Film ±100ppm/°C 1206
486-1943-ND 1 S1 SWITCH TACTILE SPST-NO 0.05A 12V
277-1578-ND 1 X3 TERM BLOCK PCB 3POS 5.0MM GREEN
277-1667-ND 2 X2, X4 TERM BLOCK PCB 2POS 5.0MM GREEN
LM60CIZ/NOPB-ND 2 U1, EXT TEMP  SENSOR TEMP ANLG VOLT TO-92-3
AP1117E33GDICT-ND 1 IC2 IC REG LDO 3.3V 1A SOT223-3
M74VHC1GT125DT1GOSCT-ND 3 IC3, IC4, IC5 IC BUFF CMOS LVL/SFTR N-I 5TSOP
478-1839-ND 2 C1, C2 CAP TANT 10UF 16V 10% RADIAL
991-1046-ND 1 X1 CONN SMA JACK STR 50 OHM PCB
*** NOTES ***
I ordered this Female SO-239 to Male SMA Cable from Amazon to connect the antenna to the transmitter.  The genders are opposite on this board than on my portable radios, so double check the gender on your cabling if you're using something different.

I already had a chassis-mount SO-239 to build the antenna.  If you don't have one, you'll want to order part # A97597-ND CONN UHF JACK STR SOLDER, as well.  If you opened the Digi-Key Shared Cart link provided, just copy and paste that part number to the quick order section to add it to the shared cart.

I bought a roll of electric fence wire to build the quarter-wave (appr. 19") VHF antenna with four radials.  
You can use wire coat hangers or any other similar type wire material for your antenna.  

 


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