System Input

Overview

A System Input exposes an internal system value — a quantity produced by the controller itself rather than measured on a wire. Which value it reads is chosen by the pin, which acts as a selector. Available values are:

  • Battery voltage — the supply/battery voltage at the controller.
  • Ignition status — whether ignition is on.
  • 5 V measurement — the controller's internal 5 V rail reading.

Use it to bring one of these into your configuration so other IO can reference it by alias.

Prerequisites & hardware

  • None to wire. A System Input reads an internal value, so there is no sensor and no source input.
  • You only need to choose which system value to read — done by the pin/selector (see below).

Add it in the app

  1. Add a new input and choose System Input as the type.
  2. Choose the pin / selector — this picks which system value the input reports (Battery voltage, Ignition status, or 5 V measurement).
  3. Give it a clear alias (e.g. the name of the value you selected).

Settings reference

This input has no type-specific settings. Which system value is read is chosen by the pin / selector, not by any field on the input.

Common settings

System Input also uses the shared settings — alias and pin. Here the pin is the selector that picks the system value. See Common IO Settings.

Example — low-battery warning

  1. Type System Input, selector Battery voltage, alias Battery V.
  2. Feed Battery V into a Compare Input set to LessThan 11500 (mV) to flag a low battery.

Troubleshooting

  • Reads an unexpected quantity: the selector is set to a different system value — reselect Battery voltage / Ignition status / 5 V measurement.
  • Other IO don't see it: check they reference the correct alias.