how to design a dead man switch for pi

[lilzz]

if the pi is unresponsive then I like the circuit to pulse a reset signal to the pi.

the question, how should I check for the Pi is non responsive software wise?
And LM335 watchdog timer would be used to generate the reset pulse ?

[ShiftPlusOne]

You don't need any external parts to do this.
http://www.bartbania.com/raspberry_pi/r ... dog-timer/