Electronics2008

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=Driver Display=

We have a small LCD to use for this. It is roughly 2"x4", is graphical (128x64) and uses a serial communications protocol. We also have a small microcontroller (uc) to use for the display. Ironically, this uc is more powerful than the uc controlling the engine...

Work continues on having the uc talk to the ECU reliably...

=Megasquirt ECU=

We are using MSnS 029y4.

Spark control
The new firmware supports spark control!

The ECU board will probably need to be modified to control the spark. It can't control the coil by itself, so we'll need either another circuit to poke the coil pack or figure out how to disable timing advance on the MSD small engine controller we currently use for spark.

This is the direct coil drive method mod:



It will also need to be wired for input from the hall effect sensor on the flywheel.

Serial communications
The serial connection is 9600 baud 8n1. Sending "S" asks the ECU to send "real time variables". The format is roughly this:

Byte		Purpose 0		Counter 1		? 2		Status 3		MAP 4		Barometer 5		Ambient Temperature 6		Coolant Temperature 7		TPS 8		Battery (V x 10) 9		EGO (V x 10) 10		EGO Corr 11		Air correction 12		Warmup correction 13		RPM 14		Pulse width * 10 15		TPSACC (ms x 10) 16		Barometer corr 17		Gamma 18		Vecorr

The status byte has its own bit order, which is:

Status Format

Bit		Component	On		Off		Else 0x03		Engine		RUN		OFF		CRANK 0x0c		Warmup		START		OFF		On