Setting up the Spiffie.org MPGuino

Depending on how you built or bought your MPGuino, you may need to follow some or all of the steps below.

1. Install the Arduino bootloader (for blank ATmega's only)
2. Download the latest MPGuino code to the MPGuino board (suggested for all MPGuinos, not required with a spiffie.org kit)
3. Test it out and setup the MPGuino variables (all MPGuinos)
4. Install the MPGuino in your car

• If you started with a factory fresh ATmega, you'll need to burn the bootloader to the chip. The Arduino.cc Bootloader page is the definitive guide.
• Go burn the bootloader and come back.

• The MPGuino software is required for a functioning MPGuino and is frequently updated. If you bought a spiffie.org kit, your kit contains the latest software available at the time it was shipped; you should check if an update is available.
• You'll need the Arduino 0011 IDE (version 0012 or later will not work, and earlier versions may not either), you can download it from (scroll down below all the pictures) or download from our mirror (Windows | Mac OS X). Follow the Arduino getting started guide (Windows | Mac OS X) with your MPGuino (steps 3,4,6, and 7).
• Open a new Arduino Sketch
• Copy the MPGuino code from
• Paste it into the blank Arduino Sketch
• Upload it to the MPGuino

• Now that your MPGuino has software installed, plug an A-B USB cable into your computer (or a 5V USB charger wallwart) and plug the other end into your MPGuino's USB socket.
• You should see “OpenGauge MPGuino vX.XX” on the display, then a screen for setting the contrast.
  • If you don't see anything, don't fear, the default contrast is very hard to read. Press the middle button a few times, hopefully you'll see the display fade in.
  • If you see a different screen then the contrast setup or the welcome screen, push both the top and bottom buttons at the same time.
• You're now in the settings/variables area.
  • Use the top button to move the cursor (underline) left and the bottom button to move the cursor right.
  • Use the middle button to increase the digit selected by the cursor. To select a lower number, simply increase the digit until it wraps around from '9' to '0'.
  • Move the cursor under 'OK' then press the middle button to save changes.
  • Move the cursor under 'XX' then press the middle button to cancel and discard changes.
• After setting the contrast, you move on to 'VSS Pulses/Mile'. From here out, you'll need to consult the table of car settings or the ecomodder forum.

Now you need to actually install the MPGuino into a car. Our installation page has more.