[XCSSA] cases with chassis intrusion sensor

[xcssa@xcssa.org]

On Friday 28 July 2006 03:30, xcssa-admin@xcssa.org wrote:
> So,
>
> I'm fond of Antec cases but so far I haven't come across any cases
> which support the intrusion sensor, save for some Dell cases that I
> probably can't order a la carte anyway.  Does anyone have any
> suggestions along these lines?

Hey Travis...
Simple SPST switch wired to a jumper or IDC header will do the trick (if you 
mobo supports it and has the header pins for the connection).


> Exactly how does the chassis intrusion sensor appear to the mobo?  Is
> it just a NC switch or something?

NO or NC.. I can't remember.. I want to say NC because I have no such switch 
in my MythTV (so it looks "open") and it's alarm state is always "on". (see 
more below)

As far as the alarm.. to detect it you need to load up your kernel modules (if 
not already there) for lmsensor/i2c signal I/O.  First whack.. just try 
running the command "sensors -f" first, to see if your system is already 
lmsensor/i2c aware.  In the old days, we had to watch for alarm status change 
on the mobo (when the case was opened) by monitoring  the /proc variable:
	/proc/sys/dev/sensors/w83781d-isa-0290/alarms

For example.  Much easier now though.

Not sure what i2c chipset you have... or what it might map to in /proc 
or /sys.  But using the sensors command, or a desktop app such as gkrellm or 
such is much easier (and nicer).  I think that there's also a daemon that you 
can use to watch the system.. but I have not played with any of that.

But ok.. let's take a step back.  Big picture here.  If the "sensors -f" 
command gave you no love, then as root, do this:
1) Run "sensors-detect" to set up your lmsensors config.
2) Then run needed modprobes to load the drivers (see notes at the end of the 
last command)
3) Set up modprobe.conf with correct drivers (so they will load every time at 
boot)
NOTE: On my mythTV system.. doing an lsmod for "lm" looks like this:
# lsmod |grep i2c
i2c_algo_bit            9033  1 ivtv
i2c_sensor              3521  2 w83627hf,eeprom
i2c_isa                 2241  0
i2c_nforce2             6721  0
i2c_core               21953  10 
wm8775,cx25840,tuner,tveeprom,i2c_algo_bit,w83627hf,eeprom,i2c_sensor,i2c_isa,i2c_nforce2

and my modprobe looks like this:
...
alias char-major-89 i2c-dev
...

4) After you get all that out of the way, now you can run the "sensors -f" 
command and it will show you all your lm_sensor data (including the chassis 
intrustion alarm):
# sensors -f
[...]
w83627thf-isa-0290
Adapter: ISA adapter
VCore:     +1.70 V  (min =  +0.94 V, max =  +0.96 V)
+12V:     +12.46 V  (min = +10.82 V, max = +13.19 V)
+3.3V:     +3.22 V  (min =  +3.14 V, max =  +3.47 V)
+5V:       +4.96 V  (min =  +4.75 V, max =  +5.25 V)
-12V:     -14.91 V  (min = -10.80 V, max = -13.18 V)
V5SB:      +5.05 V  (min =  +4.76 V, max =  +5.24 V)
VBat:      +2.75 V  (min =  +2.40 V, max =  +3.60 V)
fan1:        0 RPM  (min = 21093 RPM, div = 2)
CPU Fan:  675000 RPM  (min =   -1 RPM, div = 2)
fan3:        0 RPM  (min = 84375 RPM, div = 2)
Case Temp:   +99°F  (high =  +149°F, hyst =   +34°F)   sensor = thermistor
CPU Temp:  +77.9°F  (high =  +167°F, hyst =  +140°F)   sensor = diode
Under CPU:+107.6°F  (high =  +176°F, hyst =  +167°F)   sensor = thermistor
vid:      +0.275 V  (VRM Version 9.0)
alarms:   Chassis intrusion detection                      ALARM
beep_enable:
          Sound alarm disabled

Hope that helps...

Cheers,

Tweeks