I had been following DYIEFI and Al Grippo and Bruce Bowling for a LONG time. All their contributions to DIY Fuel Injection systems. I never really had the desire to build a Megasquirt. I prefer to use stock GM PCM’s in my projects but recently I saw Speeduino for the Arduino Mega.

I have a shifter cart outside that needs some engine work so I thought “why not build a fuel injection system for it?”…

Speeduino and TunerStudio installed pretty easily. The first thing I noticed was the display called for was an OLED. I didn’t happen to have one so I rewrote the display module to use a much cheaper Nokia 5110. The original display showed 4 pieces of numeric data in a 2×2 grid and a bargraph at the bottom.

On the 5110 I was able to fit 10 items vertically with 4 extra pixels along the top for the bargraph….

Just replace display.ino with this one…

First thing I wanted to try was a bench top simulation. That means I needed a 36-1 trigger wheel and something to spin it up. This is a common trigger wheel used on ford vehicles and can be found in most auto parts stores. I didn’t need the real thing for the test bench so I printed on on the 3D printer…

I went to the RC parts drawer and got a small outrunner motor and matching lithium, battery, speed controller, and servo tester. A small prop adapter and I put it all together. It spins up pretty smoothly. Now I just have to mount it all to a board and attach a small opto interrupter to get the signal to the Mega.

You can download the stl file I used here

That’s all for this weekend.