Hacked Gadgets Forum

November 30, 2008

GPS Data Logger using an SD Card

at 5:04 am. Filed under DIY Hacks, Electronic Hacks


If you are looking for GPS project ideas here is one that interfaces a serial GPS module to a PIC microcontroller and saves the data directly to a SD memory card. Schematics and code are available.

"The data from the GPS is logged every second with the raw NMEA sentences being written to the SD card. The data written to the card is the GSA, GGA, RMC and GSV sentences which by excluding the carriage returns this should never exceed 512 bytes per second. The data contains:

  • GGA – 78 bytes – time, fix, lat, long, altitude, horizontal dilution of precision.
  • GSA – 69 bytes – fix (none, 2D, 3D), satellites used, dilution of precision.
  • RMC – 78 bytes – time, lat, long, speed, course, date.
  • GSV – 74 bytes – satellite information (4 messages).

The total active power consumption is about 40mA to 45mA when active which in theory should give 48 hours on rechargeable batteries with 2000mAh capacity. In practice I have measured a time of 40 hours."