NAME
aps —
ThinkPad Active Protection System
accelerometer
SYNOPSIS
aps0 at isa? port 0x1600
DESCRIPTION
Theaps driver provides support for several sensors
found in some ThinkPad laptops.
The sensors currently exposed via the envsys(4) interface are:
| Sensor | Units | Typical Use |
x-acceleration |
integer | X-axis acceleration |
y-acceleration |
integer | Y-axis acceleration |
x-variable |
integer | Weighted X acceleration? |
y-variable |
integer | Weighted Y acceleration? |
temperature
1 |
degC | Unknown temperature |
temperature
2 |
degC | Unknown temperature |
keyboard
active |
boolean | Keyboard activity |
mouse
active |
boolean | Mouse activity |
lid
open |
boolean | Lid state |
SEE ALSO
HISTORY
The aps driver first appeared in
OpenBSD 3.8 and was then ported to
NetBSD 5.0.
AUTHORS
The aps driver was written by
Jonathan Gray
<jsg@openbsd.org>.
CAVEATS
Few issues can be mentioned.
- The
apsdriver does not maintain state and subsequently does not take evasive action when it thinks the hard drive is in danger. Possible actions would include spinning down the hard drive in case excessive tremor is detected by the sensors. - 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.
- The sensor values are refreshed every 0.5 seconds. Because no protection measures are taken, this is unnecessary and may have a negative effect on battery life.
- As IBM provides no documentation, it is not known what all the available sensors are used for.