Practical Arduino Cool Projects for Open Source Hardware- P41: A schematic or circuit diagram is a diagram that describes the interconnections in an electrical or electronic device. In the projects presented in Practical Arduino, we’ve taken the approach of providing both a photograph and/or line drawing of the completed device along with a schematic. While learning to read schematics takes a modest investment of your time, it will prove useful time and time again as you develop your projects. With that in mind, we present a quick how-to in this section | CHAPTER 15 VEHICLE TELEMETRY PLATFORM generated by the system is a regular CSV file using the fields specified in Table 15-13 so you can open it with a text editor or spreadsheet program. Table 15-13. Fields stored in CSVlogfile Column Field Description 1 GPS_LAT GPS latitude 2 GPS_LON GPS longitude 3 GPS_ALT GPS altitude in meters above sea level 4 GPS_SPEED GPS speed in km h 5 LOAD_VALUE Engine load in 6 COOLANT_TEMP ECU coolant temperature in C 7 ENGINE_RPM Engine RPM 8 VEHICLE_SPEED Vehicle speed in selected units 9 TIMING_ADV Timing advance in degrees 10 INT_AIR_TEMP Intake air temperature 11 MAF_AIR_FLOW Mass air flow 12 THROTTLE_POS Throttle position in 13 FUEL_RAIL_P Fuel rail pressure in kPa 14 FUEL_LEVEL Fuel level in 15 BARO_PRESSURE Barometric pressure 16 AMBIENT_TEMP Ambient temperature 17 FUEL_CONS Fuel consumption rate 18 BATT_VOLTAGE Battery voltage 379 CHAPTER 15 VEHICLE TELEMETRY PLATFORM Generate Google Earth Track Included with the project source code is a directory called OBDtoKML that contains a simple PHP script called . This script takes a logfile and extracts the latitude longitude and vehicle speed and then uses them to generate a KML file that can be opened in Google Earth. Note though that it s not intended to run on a web server even though it s written in PHP it s designed to be executed directly like a shell script. You need to have the CLI command-line interface version of PHP installed and also set execute permissions on the script. Then you can launch it just like any other script. The script takes a single argument which is simply the name of the logfile to convert and then creates a new file in the same location but with a .kml extension tacked on the end. For example on a Linux or Mac OS machine with a logfile sitting on the desktop you could open a terminal and execute. . OBDtoKML Desktop You ll then end up with a file at - Desktop that you can open in Google Earth. For .
