Setting up the Speeduino Based ECU:-
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| July 2023 | Speeduino Controller: The Speeduino based ECU is finished. It has been mounted in a plastic box, with a clear lid, so that the various indicator LEDs can be seen. The "peak and hold" driver board is also mounted inside the box for convenience. After some bench testing, it soon became obvious that the peak and hold driver transistors were getting too hot and needed a heatsink. This was added to the box in the form of a piece of winged aluminium sheet folded to suit the space available and to project into the air outside the box. Having been tested for some hours at simulated high revs (max. duty cycle), it was barely warm to the touch. The internal voltage regulator that drops 12 volts down to 5 volts for the Arduino, was also becoming very hot, so an individual heatsink was added and bolted to the side of the box to avoid any vibration fractures. It, too, now runs at a much lower temperature after testing for some hours. The timing pulses from the variable reluctance (VR) sensor, mounted close to the toothed wheel on the crankshaft, are a very low voltage. It was decided to use screened microphone cable to avoid picking up any induced noise from the engine ignition or alternator. A plug and socket, specifically designed for microphone cables, was used to connect to the ECU and the screening is only earthed at that end. The ECU requires a number of connections to the engine and various accessories. They have been divided into three groups for convenience and also so that each group can have a different sized plug to avoid any misconnections. The final wire colours for each connection are listed here for documentation purposes.
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