This is the low-power version of GPS Viewer. This version is to be used with 3 AA batteries and only with a Nokia3310 LCD.
Since in this version the PLL, external crystals and 5V are disabled, you need a Pickit2 or a Pickit3 in order to programming the new firmware. The GPS-Viewer battery operated uses a different configuration word, edits are:
- Primary Oscillator disabled
- Internal oscillator (8MHz) used
- Secondary Oscillator disabled
Other than this software modifications, you must do some modifications on the board too:
- Remove the 5V voltage regulator (IC1 : 7805CV)
- Short the input and output pins of IC1 (on the silkscreen this pads are marked with 'I' and 'O')
- Connect a 3xAA Battery Holder to X1 (screw terminal) connector
Now your GPS Viewer is a portable device, suitable for Geocaching!
Here is the source code, only for ORbit16 buyers: http://www.settorezero.com/orbit16/home/projects/gps-viewer-battery-operated/