Arduino based trip computer.

Requirements

Hardware

• Arduino UNO, preferably with a crystal oscillator
• MTK33x9 GPS module (or equivalent)
• LCD 2004 display module
• Shift-register based controller for LCD display (or I2C, but way slower)
• resistor bridge (or optocoupler) for injection probing
• resistor bridge for brownout detection
• push buttons and appropriate resistors
• super capacitor

Software

• Arduino IDE
• TinyGPS
• LiquidCrystal
• EEPROMAnything

Inputs

Injector line

Injector line has to be connected to pin 3 of the Arduino UNO board, through a voltage divider. I recommend dividing the voltage by 3: maximum injector voltage should be capped at 15V which gives 5V after division.

Buttons

A0 pin.

Input voltage

For brownout detection, input voltage has to be connected to pin 2 of the Arduino UNO board, through a voltage divider. It must also be connected (after the same voltage divider) to the A1 pin, for measurments.

GPS module

Serial pins: 0 and 1.

Outputs

LCD 2004 display

Backlight is connected to pin 10. Shift register data is connected to A4, clock is connected to A5.