GPS Board

One day I stumbled up Karman's blog ( where he made a tiny little GPS device. This project is what got me hooked into using the 0.96" i2c OLED displays that I have been using in everything. After several revisions and FTDI design difficulties I'm finally happy with the results. Parts used are:

-Atmega328P (Arduino Pro or Pro Mini bootloader, 3.3V @ 8Mhz)
-MTK3339 (Adafruit Ultimate GPS)
-FT232RQ (USB interface)
-MCP73833 (liPo battery charger)
-TPS61200 (boost power supply)
-TMP75AI (temperature IC)
-Adafruits Ultimate GPS (battery backed)
-custom i2c 3.3V OLED display
-5-way navigation button and pushbutton
-reset button

The code allows you to:
-view streamed GPS time in 12 or 24 hour format
-change timezone when viewing time
-view temperature on the board
-view satellites on view
-view speed in KPH
-mark GPS points (working on a fix for this) now which crashes the board)
-view distance travelled

Video of the previous revision in action with two pushbuttons on the rear:

Karman's updated blog is at: where an older Rev1.0 board is shown. The new Rev 1.1 board has the OLED display on top of the GPS receiver which diminished the sensitivity slightly. Testing has gone well so far with satellite fixes not a problem in under a minute. This also makes using the menu navigation buttons easier to use as well. 

How to modify the code

Download the Arduino IDE located at
Download the FTDI interface driver located at
Power up the GPS Board, connect it to a mini B USB cable and you should see the FTDI driver being loaded. In the IDE pick
Tools, Board, Arduino Pro or Pro Mini (3.3V, 8Mhz) w/ ATmega328
Tools, Serial Port and most likely the bottom one
To verify everything is working you could select
File, Examples, 01.Basics, Blink and then upload
If the Orange LED blinks at 1Hz then your drivers are properly installed and everything is working.

Below are a few files that may come in handy.
-PCB files in Altium Designer for making or modifying your own GPS board
-the original GPS Cube sketch (it appears to have a problem rebooting or going black when marking a GPS location)
-modified GPS Cube sketch removing the mark GPS location
-button test code that I use after assembling a board
-SD logger sketch that reads, writes and erases a log file when using the add on SD Card Board.

The GPS Board can be purchased for $75 at

mike rankin,
Feb 10, 2014, 4:37 AM
mike rankin,
Dec 30, 2013, 4:56 AM
mike rankin,
Apr 14, 2014, 9:07 AM
mike rankin,
Oct 22, 2013, 5:44 AM
mike rankin,
Oct 22, 2013, 5:44 AM