Megasquirt 3 - Generic PWM outputs

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Introduction

The Generic PWM system allows up to six independent open-loop PWM (pulse width modulated) or on/off outputs. The duties are programmed through an 6x6 table of rpm vs. Y-axis. For the Y-axis you can choose from MAP, %baro, TPS, MAFMAP, CLT, MAT. The output is typically used to drive a solenoid valve (PWM mode) or relay (on/off.) PWM is a method that pulses an output on and off, the on-time percentage (duty) is variable, this is often used for idle valves and allows a valve to "float" in-between closed and open for variable flow rates.

Settings

Enable generic PWM - Turns this PWM channel on or off
Output port/pin - Selects the output pin to use
On-off or variable - On/off or variable PWM output
On above duty - For on/off mode, duties in the table above this value turn the output on.
Off below duty - For on/off mode, duties in the table below this value turn the output off. (Leave a gap to prevent chatter.)
Frequency - For variable outputs this sets the frequency.
Load Y axis - Choose from MAP, %baro, TPS, MAFMAP, CLT, MAT for the Y-axis of the table.
CLT/MAT units - This settings chooses the temperature scale in use. It can only be set through the "Generic Sensors" menu.

Wiring

MS3X PWM wiring

The outputs on the MS3X are ready to use. For outputs that are not on the MS3X you will typically need to DIY a circuit. See the MS2/Extra documentation for examples.

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No part of this manual may be reproduced or changed without written permission from James Murray and Ken Culver.