Random…. More like a scripted Sequence !!!

[tekart]

Almost all CPUs (including PICs I think) use a simple logic circuit known as a "pseudo random number generator". It is basically a shift register that feeds back on itself producing a finite series of random numbers. In the pic I believe it is around 36K words long, but I may be wrong. Here is a good article about this:
http://www.maximintegrated.com/en/ap...ex.mvp/id/1743

One of my tricks for generating random numbers is to read ambient light using a photocell and a resistor to create a divider. This feeds into any A/D input with as much resolution as you need.

I have also successfully used pedja089's solution of timing intervals between button presses if they are frequent enough.

[andybarrett1]

Interesting read Tekart..

Will have a play with the LDR (PhotoDiode) on the ADC.... Sounds like it might work !!

Thank you all again

Andy