Thanks guys, that sounds promising.
So to make sure I fully understand, to turn the screen back on, would it be enough just to move/pick up the device, i.e. no need to push a (power) button? (That is for a set period of let's say 30 minutes until the device goes fully to sleep.)
In short, I am looking for a device behavior like I was used to from my URC MX3000 or Pronto remote control days => picking up the remote turns it on - no need to press extra buttons.
When an Android screen sleeps, it requires a press of the power button to restore it. There are a number of apps that can use sensor data to wake the screen (proximity, ambient light, accelerometer), some work better than others. IME, the most reliable of these was ones using the proximity sensor (which of course the Nexus 7 lacks). You'll have to play around with some of them to find one that works for you. I gave up on them because they are either too sensitive for general use, or not sensitive enough.
I suppose the ideal situation would be to use Tasker, and set up a profile to set a var when iRule is the front app. Then a sensor event to wake the device if the var is set.