UK High Altitude Society

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  • GM862-GPS - got
  • Circuit Design Radio Module - (Morse Beacon) - got
  • Cutdown Circuit (based on a Mosfet) - got and built circuit
  • 3.7v Lipo Battery - sparkfun UK Supplier - got
  • GPS antenna - got
  • GSM antenna - still to get Active Robots
  • uALFAT Data Logger - got
  • 2Gb Micro-SD card - ordered


  • Downward facing camera
  • Similar design to FHALP-1 with balsa wood cross struts however won't be in a square to accommodate the camera.

Things to do

  • Design Payload
  • Build Morse Beacon
  • Sort out code especially cutdown code
  • Design Payload
  • Build Payload Casing
  • (Rig Camera)
  • Get Battery
  • Order new parts from RS
  • Finish RubyCocoa software
  • Setup GM862
  • Build Cutdown circuit


So the plan is to make a morse beacon that pulses on and off at 1Hz and then every minute the gm862-gps takes over and pulses out the time,lat,long and alt. To achieve this without using a complicated PIC I've got hold of some CMOS 555 ICs which will be set up to pulse the radio at 1Hz and the GM862 will pull the reset to ground and toggle the pin itself.

Its not the best design in the world however early testing seems to work (well I can hear the 1hz pulse on my radio). The next step is to link it up to the gm862 and start sending some actual data.


Picture of GM862, lipo 2000mAh battery, radio module and data logger (not yet wired up) - lots of the wires are for development and connection to my laptop!

Mission Badge

projects/firefly/fhalp-2.txt ยท Last modified: 2008/07/19 23:33 (external edit)