Microsquirt Introduction

The Microsquirt ECU is a pre-assembled variant of the Megasquirt-2 based ECU, it comes in a compact case and can be waterproofed. It supports up to four cylinders wasted spark (two spark outputs) natively and batch fire fuel (two channels.) With external coil drivers it is possibly to run up to V8 wasted spark directly. EDIS4, EDIS6, EDIS8 can be used as standard.

Physical dimensions

External connections and wiring

* diagram to go here *
(Note: this section needs extending!)
The sensor inputs to the Microsquirt module are largely the same as other Megasquirt products.
The injector outputs are capable of driving four high impedance (14 ohms) injectors each. If you have low impedance injectors (typically 2.5 ohms) then it is advised to use series resistors or an external peak and hold box. Do not directly connect low impedance injectors if you want reliability.
The coil outputs may either be wired as high-current outputs suitable for driving a single inductive coil each or as a logic output.
The logic coil outputs are suitable for driving LS1 type ignitors or other logic ignition modules. When wired as a logic output, do NOT connect directly to a coil.

Software

As the Microsquirt is essentially a Megasquirt2, you should use the MS2/Extra firmware and documentation.
The manual is here.
Be sure to use the www.msextra.com forum for any support questions.

Microsquirt Access board

The access board provides a map sensor, a real serial connector, tell-tale LEDs and screw terminal access to the connections from the Microsquirt. This can be useful in a test environment where connections are temporary. Normally in a car/bike installation the loom would be made directly to the Microsquirt connector to avoid corrosion problems inherent with screw terminals.

If you have a question, comment, or suggestion for this FAQ please post it on the forum.

No part of this manual may be reproduced or changed without written permission from James Murray, Ken Culver and Philip Ringwood.