High Altitude Balloon

Project Daedalus –

1. Team (July – August, 2012)

Raymond Cheng
Daniel Kim
Henry Liu
Jeff Matunan
Oak Shannon
Cameron Tully

2. Overview

The team worked hard during July and August, 2012 designing and constructing devices for their high altitude photography project. Their aim was to launch a camera in mid-August that would take photographs of Earth from near space. They designed, built and bench tested both transceivers. Much of the work was done at home. Some of the tasks, such as masking, etching, drilling and populating the printed circuit boards were completed in the Churchill electronics shop. The team worked closely together assisting each other, and solving problems. Programs had to be compiled and installed on microcontrollers. A lightweight instrument enclosure capable of withstanding widely ranging temperatures was designed and constructed. Unfortunately, during final testing on the day prior to launch the transceiver failed. Since two team members had to travel to Ontario to begin their undergraduate studies the launch was postponed. Despite this setback, the team agreed that the project was an amazing experience.

3. Photographs

Team

Instrument Platform

Balloon Transceiver

Ground Transceiver

4. Circuit Schematics

Receiver Board SchematicRF Amplifier Schematic (KiCad)

Note: The RF Amplifier was done using KiCad. KiCad can be downloaded here

5. PCB Designs

PCB designs to come soon!

6. Links

7. Schematic Diagram and Main Board

Main Board Schematic in ISISMain Board PCB in Proteus AresPower Supply PCB in Proteus Ares

The mainboard is the board that goes up with the balloon in the enclosure. It has many functions:
- processing sensor input from external temperature sensor, internal temperature sensor, and gps (reading and parsing input from gps was tedious)
- logging data to the onboard 32kb EEPROM chip (data included location, temperature, and potentially a barometric altitude sensor that we chose not to include due to its cost)
- usb connection to computer for downloading the logged data once we recovered the module
- shutter control of the dual camera setup (the setup was one camera for photos, and another camera for video. I think I had it set to take a photo every 5 minutes, and monitor the video camera for any issues)
- sending gps data via 2.4ghz radio transmitter to ground, and control of the radio amplifier
- control of a buzzer which would make beeping noises upon landing to make locating the module easier

There is a slight wiring issue on the ISIS schematic, but does not affect the operation of the board.

Power supply unit:
- Input: 7 to 40V DC
- Output: 5V, maximum 2A
- Output: 3.3V, maximum 0.5A

It was connected to a 12V 5500mAh lithium-ion battery, which guaranteed us a run time of at least 5 hours with the radio continuously broadcasting gps coordinates.

To come: receiver board, rf amplifier board, firmware, and software for error-correction on the receiving side (due to the long distances involved in transmission we had to implement primitive error-correction algorithms for the radio).

Henry Liu