Download GPS-VTI Development

GPS-VTI
by
Tony Barry
presented by Dave Gault
Overview
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minimal wiring (less than thirty wires to solder)
no chips, transistors, or surface mount to solder. Just wires + LEDs + switch.
doesn't need USB to function, can run off 12V DC
based on Arduino AVR architecture (MEGA1280).
uses Sparkfun breakout board for MAX7456
GPS is EM406A from USGlobalSat
Add - two LEDs, one switch, two RCA sockets, a case and an afternoon to assemble
code is open source released under “Berkeley 3-clause software licence”
The circuit diagram
The setup screen
The timing screen
HHMMSS
milliseconds
field end
Vsync period
field counter
Summary
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Cost ~$100 and an afternoon with a soldering iron
Software to load the program into the microcontroller is free
Code is still in development, currently at beta v16
Independent QA review is yet to be arranged
Should have a second device ready for testing in the new year
usage is relatively simple.
 Connect to camera, monitor, 12V or USB port of laptop - power on
 Switch to "Setup“
 Wait for GPS fix (may take a few minutes)
 record observer’s site details
 Switch to "Run"
 Wait for 10 seconds for the GPS’s ZDA mode to start
 Record the occultation.