Responses to this post: How does RPi "know" when it hasn't got enough power indicate that there is a digital input somewhere on the RPi which indicates what the supply voltage has dropped off too low.
How can this be accessed by a script, please? Ideally, it would be Python, but if I can find the Linux file containing the data, I can work with that.
(I'm hoping to get really lucky and get access to the supply voltage, but the indications are that the RPi only has access to a digital signal indicating "too low".)
Thanks.