Saturday 13 June 2015

(Vacation) WEEK EIGHT: 8 Jun to 14 Jun 2015

Task: GPS Tracking of Solar Car

In 2013, the GPS module was placed on SunSPEC3 for the GPS coordinates. By placing the GPS module on the solar car itself, a more accurate terrain can be plotted.

Figure 1. Plotting altitude against distance
The above figure is the terrain obtained by the SunSPEC 3 team after the race. GPS tracking allows us to know the conditions of the route. With reference to the route profile, the telemetry team is able to strategize for the car to perform optimally.

As we will be using Arduino for programming, GPS module and GPS shield must be arduino-compatible. In this case, we looked into the GPS Receiver Module (EM-506).
Figure 2. GPS Receiver EM-506 Module
This receiver module has 48 frequency channels to choose from. It has extremely high sensitivity. Current drawn is small which is favourable as we have limited power from solar panels and batteries.

With the help of an Arduino GPS Shield and data logging shield. The GPS coordinates can be transmitted to computer and data can be saved for analysis. 

Figure 3. Arduino UNO with GPS Shield and EM-506

Programming of GPS tracking is rather easy with tutorials in the arduino library. Here's an exampe of the GPS program: 
Figure 4. Schematic of GPS tracking with Display
How to use the GPS Shield?

In order to operate the GPS, some settings must be done on the GPS Shield itself. 

There are two switches, one of  it is the power switch to turn on and off the GPS. The other one is the UART / DLINE switch, which controls how the Arduino communicates with the GPS Module. 

When set to UART mode, it will configure the board to use the hardware serial, which is the built-in Arduino hardware serial. It uses pin 1 and 2 for transmitting and receiving, communicating with the satellite. 

When set to DLINE mode, the board will be configured to use the software serial. The software serial library must be included in the code for the program to run. By default, pin 2 and 3 will be used for transmitting and receiving. 

In order to upload a program to the Arduino with GPS shield attached, switch must be set to DLINE mode.