Dual Spark capability: The major new feature in MicroSquirt® v2.822 embedded code is the capability to use two inputs and two outputs for ignition.
No pulse width modulation (PWM) to limit injector current. The fuel injector drives will max out at 5 amps each, enough to drive one low-impedance (or 4 high-impedance) injector per bank. To get everything to fit without lots of heat sinking, MicroSquirt® uses the ST VND5N07 from STMicroelectronics to drive the injectors. This is not a ‘peak and hold’ driver, but it does clamp the current at 5 amps, so it can be used with one low-impedance injector per bank, however the close time may be a tad higher (or you can use resistors). For up to 4 high-impedance injectors per bank. For example, for motorcycle use MicroSquirt® will be perfect!
No internal MAP sensor. In order to shrink the ‘footprint’ of MicroSquirt® , the MAP sensor was left off the board. An external MAP sensor, such as those from General Motors products, can be used instead. See the MicroSquirt® hardware page for more information on MAP sensors.
No stepper IAC control: In order to make room for the dual ignition inputs and dual outputs, the ability to to control a stepper IAC was removed. PWM Idle valves, as well as on/off idle valves, can still be used.
Different connector and case. The MicroSquirt® board uses the 35-pin AMPSEAL connector and a sealed case to make a fully sealed unit. Amazingly, the board is the physical size of a business card – connector and all. MicroSquirt’s® board size, including the 35-pin AMPSEAL connector, is very small – 2.4″ x 3.5″ (61mm x 89mm), just slightly bigger than a credit card.
Pre-loaded code: Unlike MegaSquirt® -II, MicroSquirt® comes with the embedded code already loaded onto its processor. You can still upgrade to newer versions of the code as they are released, of course, but you won’t have to load the code initially to get MicroSquirt® working.
The bootloader is externally accessible, so there’s no need to open the case, even to load new code. And the serial RS-232 signals come out of the AMPSEAL connector (instead of a DB-9 on the front, as with MicroSquirt® ). The board is sealed in a weather proof enclosure.
MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles <http://www.megamanual.com/tamp.htm>. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.
MicroSquirt® is a registered trademark of BG Soflex LLC