GPS-VTI by Tony Barry presented by Dave Gault. Overview minimal wiring (less than thirty wires to solder) no chips, transistors, or surface mount to solder.

GPS-VTIGPS-VTI

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Tony BarryTony Barry

presented by Dave Gaultpresented by Dave Gault

OverviewOverview

minimal wiring (less than thirty wires to solder)minimal wiring (less than thirty wires to solder) no chips, transistors, or surface mount to solder. Just wires + LEDs + switch.no chips, transistors, or surface mount to solder. Just wires + LEDs + switch. doesn't need USB to function, can run off 12V DCdoesn't need USB to function, can run off 12V DC based on Arduino AVR architecture (MEGA1280).based on Arduino AVR architecture (MEGA1280). uses Sparkfun breakout board for MAX7456uses Sparkfun breakout board for MAX7456 GPS is EM406A from USGlobalSatGPS is EM406A from USGlobalSat Add - two LEDs, one switch, two RCA sockets, a case and an afternoon to assembleAdd - 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”code is open source released under “Berkeley 3-clause software licence”

The circuit diagramThe circuit diagram

The setup screenThe setup screen

The timing screenThe timing screen

HHMMSS milliseconds Vsync period field counter field end

SummarySummary Cost ~$100 and an afternoon with a soldering ironCost ~$100 and an afternoon with a soldering iron Software to load the program into the microcontroller is freeSoftware to load the program into the microcontroller is free Code is still in development, currently at beta v16Code is still in development, currently at beta v16 Independent QA review is yet to be arrangedIndependent QA review is yet to be arranged Should have a second device ready for testing in the new yearShould have a second device ready for testing in the new year

usage is relatively simple.usage is relatively simple. Connect to camera, monitor, 12V or USB port of laptop - power onConnect to camera, monitor, 12V or USB port of laptop - power on Switch to "Setup“Switch to "Setup“ Wait for GPS fix (may take a few minutes)Wait for GPS fix (may take a few minutes) record observer’s site detailsrecord observer’s site details Switch to "Run"Switch to "Run" Wait for 10 seconds for the GPS’s ZDA mode to startWait for 10 seconds for the GPS’s ZDA mode to start Record the occultation.Record the occultation.