Monday, May 28, 2012

And more, now with Android

I modified BlueTerm to add logging the received data to a gzipped file (in downloads named BT-datetime.txt.gz).  I didn't originally have a WAKE_LOCK to keep the CPU on so it kept cutting out, and I had a hardware problem on the one board I built that gives the BT module apoplexy on occasion - the LED doesn't blink, it just goes off but the GPS is still working.

I think I resolved it and am getting good logs.  Still some rare J1850 errors.  And I need to port my KML converters and such, and sync the J1850 data with the GPS position data (the fix comes out some random number of milliseconds - usually in the hundreds - after the event given the PPS location).

I'm also using a 7805 to drop the voltage so the regulator on board won't overheat at the moment while I sort out the alternatives.  I can't just use a resistor since during crank the voltage drops too far and it shuts off long enough to stop the GPS and break the BT connection.  The 7805 leaks so instead of 100nA, it draws 2.5mA when idle.  I have a few ideas but it would be nice if there was a 3.3v switcher that efficiently downconverted 12v and would work with nanoAmps up to 150mA.

2 comments:

  1. Is this for the Valentine One or another GPS project?

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  2. This is for my Harley GPS J1850,not thev1

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