Just a quick update. I haven't spent much time on it as I've the usual end of month rush but progress is reasonable.
Got the 'output compares' working so I can drive the injectors with hardware timing for very accurate fuel control (1.5uS accuracy)
Got the I2C working in order to write to the D-A to set a sensible level for the trigger signals (default on the d-a was 'switched off')
Made a test rig, shown below, to feed trigger signals to ECU. (I will connect the dizzy to a motor driven from a variable power supply for easier use)
Sussed out the interrupts on the processor for the cam & crank trigger signals.
Written the interrupt routines to measure RPM, drive the injectors in correct sequence for a time set in the main loop (currently fixed, will be output from map & corrections), drive the ignition according to precharge and 'fire' points specified in main loop. (currently fixed, will be output from map & corrections).
Still to do before it runs an engine (only a few hours work away now for crude running on fixed timing, fuel set from MAP sensor only).
Make up adapter loom from standard toyota plugs (which I now have) to the D connectors.
Fit the remaining injector drive transistors & diodes.
Get the A-D up & running to read MAP sensor (and others)
A few more sums for ignition timing so I can set a fixed timing of 20 degrees (currently fixed time after 30 degree trigger)
A few more sums to set fueling proportional to manifold pressure.
To do before I can start running ECU in car to start building testing hours.
Add ignition and fuel map functions. Maps can be fixed in software initially (copy of my current link G3 maps)
Write initial software for slave processor to read temperatures and drive idle solenoid.
Get I2C comms running between the procesors.
Add coolant and air temperature correction map functionality.
Add idle control.
At this point the ECU should run the engine as well as my current link G3, without knock control or any of the other safeguards I will be building in. Target for this is end of March still.
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