From this post on I am turning the blog language into English.
While cleaning my storage room I found an old GPS 12 channels antenna:
branded Lact.DE, UG-200 model, power supply 3.3V - 12V, Current consumption: 90 mA.
GPS Antenna UG-200 specifications
A fast look to my Arduino hardware resources: Arduino Uno, SD shield, LCD 4x20.
Well, I was asking to myself why don't I try to plug it all together to get a real time GPS saving the data on a SD card in a csv file? and maybe also visualize the data on Google maps?
To visualize the SD saved data on Google maps I found a very useful online software:
http://www.gpsvisualizer.com/ by formatting my data following this
tutorial.
Then uploading the file
in this page by the "File #1 Browse" you'll get a map like this:
And by clicking on the red triangles, (one triangle every minute), you'll get the info in the selected point: speed, UTC date and time, Latitude and Longitude.
As you can see I designed it for my sail-boat :)
Ok guys, Le'ts have a look at the hardware; what we need is very basic:
Problem to solve: The Antenna output signal is in RS232 format and not TTL so we have to find a way to have it in TTL.
Opening the GPS antenna I found inside a chip labelled SP385EET, and having a closer look you can see tx and rx cables connected to pins 9 and 8 of this chip.
Checking with an oscilloscope I found TTL signals on pins 12 and 13 (input pins of SP385EET before being converted), with some luck it could work.. so I wired tx and rx cables to this 2 pins instead of 9 and 8.
You can find more info in the
datasheet.
I decided to visualize on the lcd screen the following info: Latitude, Longitude, Speed (in knots), track, number of satellites, data record status on SD memory (ON or OFF), and the battery status.
Yes, the system has also a switch to turn On or Off the data recording.
In the end I designed and printed two PCBs to wire everything together, the first one is like a shield on Arduino Uno and the second one for the LCD screen with the backlight trimmer and two resistors.
To design the PCB I used a freeware software
FidoCad.
You can download the PCB file from
here and the software from
here.
It is written using old IDE 0.022 because this project was made last year.
All my projects are free for no commercial use.