aps(4)

aps4

Thinkpad active protection system accelerometer

Usage

aps0 at isa? port 0x1600

Overview

The aps driver provides support for several sensors found in some ThinkPad laptops.

The sensors currently exposed via the sysctl(8) interface are:

SensorUnitsTypical Use
X_ACCELUnknownX Acceleration
Y_ACCELUnknownY Acceleration
X_VARUnknownWeighted X Acceleration?
Y_VARUnknownWeighted Y Acceleration?
Temp1uKUnknown
Temp2uKUnknown
Keyboard ActivebooleanKeyboard activity
Mouse ActivebooleanMouse activity
Lid OpenbooleanLid state

Caveats

The aps driver does not yet maintain state and subsequently does not take evasive action when it thinks the hard drive is in danger.

The Y axis on X40 and possibly other models seems to be inverted. It is unknown how to distinguish between different versions of the accelerometer to compensate for this in the driver at this time.

As IBM provides no documentation, it is not known what all the available sensors are used for.

Releases

44 releases since OpenBSD 3.8; the text changed 6 times.

  1. 3.8
  2. 3.9–4.0
  3. 4.1
  4. 4.2
  5. 4.3–5.0
  6. 5.1–5.3
  7. 5.4–8.0

History

The aps driver first appeared in OpenBSD 3.8.

Authors

The aps driver was written by Jonathan Gray ⟨[email protected]⟩.

From man 8.0-current-20261101 in OpenBSD 8.0-current (2026-11-01). Parsed by carta from the page's mdoc source.