Month: January 2013

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Balloon project

notes

Cost estimates rising. I think we’re looking at around $700 possibly more. The balloon, parachute, and helium costs are fixed. Need a source of helium. Might try the sun.

Tracking options:
  • Commercial service like Spot messenger GPS. $100 plus annual service fee of $150
  • Amateur RTTY + GPS – Have built a prototype using arduino. cost will be about $120 – but arduino can be used for many other purposes. Can be tracked by anyone with 70cm receiver. ie., all hams.
  • Amateur APRS – Allows worldwide automatic tracking via APRS network. Cost will run about $250 but provides the most extensive automated tracking network possible. Recommend using Byonics equipment for this.
  • Xbee 900mhz 9600 baud radios (from Sparkfun electronics) These radios provide accurate long range tracking, and interface easily with arduino. Down side is that nobody else can track the flight.
  • Emergency GPS tracker units. Like the ones that skiers use. Haven’t priced these but they would provide a way to find the payload long after it lands.
Sensors:

Recommended sensors would include temperature, pressure, altitude, light levels. These should be fairly inexpensive and can be connected to Arduino

Cameras:

Originally I had wanted to have some kind of live web cam thing, but it appears to require extremely high rate of radio transmission which means live tracking with a mobile unit that has a high gain antenna with programmable azimuth and elevation.

So… logistically, the easiest alternatives then involve the need to recover the payload. These include

  • ordinary camera which is triggered at regular time intervals
  • video camera which runs all the time
  • web cam hooked to a raspberry pi which saves data to SD card
  • web cam/ sd card combo controlled by arduino – more difficult.

 

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HAB APRS tracking

Notes on high altitude balloon tracking using APRS.

Byonics TT3 is another option – a separate APRS encoder, to be combined with GPS and transmitter, for example:

What are all the pieces I will need to make a complete TinyTrak APRS tracker?

  • You will need:
    • a TinyTrak3 or TinyTrak4 controller (The primary difference is that the TinyTrak4 can decode incoming stations, so you can monitor others if you connect a computer.)
    • a serial GPS recevier, such as our GPS2. (We sell both TinyTraks as a combo above with a GPS2.)
    • a radio/power interface cable to connect to the mic & speaker or data jacks of the 2 meter mobile or handheld radio you will use. (If you don’t have a radio, consider our Micro-Trak line which include the transmitter.)
    • a F-F null modem cable to connect the TinyTrak to your computer serial port for configuration, and possibily for operations for the TinyTrak4.
    • a USB to serial adapter if your computer doesn’t have a serial port.
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RTTY with Arduino

Transmitting on 434.650 MHz.

Successfully ran the configuration described in this article

By Anthony Stirk at UKHAS

http://ukhas.org.uk/guides:linkingarduinotontx2

Have only tried 50 baud – but the beacon ran for over an hour without errors. The receiving   setup was done on a Windows 7 computer:

  • Funcube (software defined radio)
  • FCHID (software to tune the Funcube)
  • Spectraview (demodulate signal from Funcube to SSB)
  • FLDigi (decode RTTY using custom setup)

The bandwidth of the RTTY signal was close to 900 instead of something more reasonable like 50. This can be adjusted by trying various resistor values in the voltage divider circuit.

Next steps include building antennas and increasing the baud rate.

 

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using a WiFi router as a closed local network

I set up a WiFi router today at school, with no internet connection to use for ssh logins to Raspberry Pi and OSC experiments with Arduino. It has the same SSID as my home router so it will be interesting to see what happens when I go from one place to the other. 

Update: Actually this works great. Have been using it for any situation that requires OSC.