History
The Megasquirt's predecessor was the EFI332 project, led by Bruce Bowling and Al Grippo. EFI332 development started around 1999 and culminated in the release of about 200 kits in 2000. The system used a 32-bit MC68332 microcontroller fromCurrent Products
For a more detailed cross-reference of the features available within the MegaSquirt range of products, seHardware
The assembled controller takes input from several sensors in order to manage the fuel injectors, including aMicrocontroller
The version 1.0 MegaSquirt used an 8-bit Motorola MC68HC908 microcontroller, and all versions of the main board support this processor. The later MegaSquirt-II processor upgrade daughter card includes a 16-bit MC9S12, and is a step up from the original MC68HC908 processor MegaSquirt. The current Megasquirt-III uses a 16bit MC9S12XEP100 processor running at 50 MHz which includes a 100 MHz RISC core.Printed Circuit Board
The first group buy ofFirmware
Firmware for MS-I chip
*standard V3.000 code :This is the default pre-loaded code from Bowling and Grippo. It is a simple and effective fuel injection controller with an 8x8 fuel table for speed density or alpha-n. Narrow band or wide band oxygen sensors can be used for closed loop control, and an on/off idle valve may be used. *MS1/Extra (MegaSquirt 'n Spark-Extra) :MS1/Extra is a firmware modification to the original Bowling and Grippo MegaSquirt written by Philip Ringwood and James Murray (with contributions from many more). As the name implies it adds ignition management, as well as a large number of other features such as boost control, nitrous, fan control, programmable outputs, water injection and more to MegaSquirt. Hardware modifications are required to run ignition and the learning curve is steeper than a fuel-only implementation, but many hundreds of users use the "MS1/Extra" firmware. The firmware was very actively developed and is now a stable alternative to the base MS code. Most MegaSquirt vendors ship the MS1/Extra firmware as standard on MS1 boards. The firmware is designed to operate using either a supported ignition system, such as GM HEI, orFirmware for MS-II chip
*standard MS-II code :This is the default Al Grippo code that you can load onto your MS-II board. The code has (multiple) 12x12 fuel and spark tables, stepper IAC control, PWM idle valve control, several user-configurable spare ports (for things like boost control, water injection, fan control, etc.), self-tuning functions (Automatic Mixture Control - AMC), and fuel control to 1 μs (100 times more resolution than MegaSquirt-I). MS-II can control distributors or EDIS ignitions and decode many standard toothed crank wheels. Additional features includes X-Tau transient enrichment compensation (acceleration enrichment), nitrous control with fuel and spark adjustments, enhanced closed-loop mixture control w/ wide band sensor AFR targeting, two types of rev-limiting, MAP/MAF/alpha-N fuel control, injector test mode, flex fuel (gasoline/E85) with appropriate sensor, and many more. :See the Megamanual for download and documentation *MS2/Extra code :This is an extension of the base code, adding many of the much needed MS1/Extra features to the MS-II chip. Enhancements include wide support for OEM crank/cam wheels, wasted spark and COP ignition, closed loop idle, EAE, boost control, nitrous control and many other features. Latest test codes support 4 cyl sequential fuel. Code is licensed for use on genuine B&G products only.Firmware for MS-III chip
*standard MS-III code :This is the default MS3 code that you can load onto your MS-III board. The code has (multiple) 16x16 fuel and spark tables, support for up to V8 sequential fuel and spark, stepper IAC control, 2 or 3 wire PWM idle valve control, fuel control to 1 μs, several user-configurable spare ports, specific features for boost control, water injection, fan control, nitrous control etc., MS-III can control distributors or EDIS ignitions and decode a wide range of OEM toothed crank and cam wheels. Additional features includes enhanced transient enrichment compensation (X-Tau and EAE acceleration enrichment), enhanced closed-loop mixture control with wide band sensor AFR targeting, closed loop idle control, various types of rev-limiting, MAP/MAF/alpha-N fuel control, injector and coil test mode, crank/cam input diagnostics, SDcard datalogging, flex fuel (gasoline/E85) with appropriate sensor, LPG support, and many more.A history of Innovation
The MegaSquirt line of ECUs, particularly MegaSquirt-3 and MS3Pro, have commonly found themselves to be innovators in the Engine Management System world. The creative thought and innovative efforts of the developers and the lead distributor (DIYAutoTune) has brought about many advancements, only years later to be copied and imitated by others in the industry. Perhaps the first to implement (in 2010) Real-Time o2 Sensor based fueling corrections on an individual cylinder basis of any aftermarket ECU, this allowed the ECU to treat each cylinder of the engine individually, with the ability to tune the fuel injection system for the precise amount of fuel each cylinder needs to account for different air distribution caused by uneven airflow through the intake manifold and cylinder heads. However going back much further, to the early days of MegaSquirt-2 in 2005, the Output Test Modes feature was implemented allowing all of the ECUs critical outputs, from the fuel injectors, to the ignition coil, fuel pump, idle valve, and more to be 'tested' from the TunerStudio Tuning Software to allow the user to verify their wiring/installation is proper, and to verify individual components of the EFI system are working properly. This diagnostic feature is one of many that set the MegaSquirt line of ECUs apart from all others for over a decade. Alas... others in the market have since begun to imitate these features. We'll just have to wait and see what new creative tech the team at MegaSquirt and DIYAutoTune think up next.Licensing issues
The licensing surrounding Megasquirt has at times been misunderstood. :The hardware designs and application firmware are copyrighted by Bowling & Grippo and subject to patents. :The source code of the firmware(s) are available to download for peer review and end-user modification, but the code and derivatives are only licensed for use on official Megasquirt hardware. :The success of Megasquirt has spawned a number of unlicensed clones.References
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