PWM Outputs

Overview

The ECU has a number of Pulse Width Modulated (PWM) outputs that can be used to control various devices. These outputs may be assigned to different functions such as VV control, Idle valve, Wastegate, Servo.

Some PWM outputs may be claimed by specific functions. For instance, if Active Throttle is enabled, it owns a bridge driver and prevents others attempting to use the output, unless e.g. Act T 1 No Drive is set to ON.

Duty Cycle

The duty cycle of a PWM signal is the ratio of the ‘on’ time to the total period of the signal. The frequency of the PWM signal is the rate at which the signal repeats. Over time, this produces a proportional control signal with low power loss.

For devices that require a simple on/off control signal, use a digital output channel instead.

Configuration

PWM outputs must be enabled using options in the calibration and are typically routed to from ECU functions using additional calibration options.

Some PWM outputs are used for specific features such as active throttle, so some care is required to avoid conflicts.

Restrictions

PWM1-16 are fixed to individual pins, however, PWM17 onwards are assignable to any simple output pin. In the pin-outs diagram/table, these fixed PWMs have a code of ‘Pnn’, where ‘nn’ is 01-16.

PWM Output Pin Assignment

For PWMs that may be assigned to output pins, pin assignment options are available in the calibration.

e.g. Out PWM17

As with any other output pin assignment, using a negative value will invert the output signal.

Oil Feeds

See Oil Feed Outputs for details on the Oil Feed channels - which can either use PWM outputs or generate low-speed PWMs in software on simple digital outputs.