Max voltage on analogue input

[matttargett4]

Hi,

ive been messing about with my new pokeys 55t and have set up the analogue inputs, in the instructions on how to do so (from a thread here i beleive) it suggests that the 3.3v pin on the board is used to supply power to your pot, however  recall seeing in the destruction manual that each pin has a max of 5v i think. So i was just wondering what the max i could supply to an anolgue input was since  dont want to connect it to 5v and kill it since im well pleased with it?
Probably showing my ignorance but whilst im asking how is the best way to isolate an anologue input, i cant opto isolate it since its analogue i guess so what can i do to try to stop any noise or cock ups hurting the board, ne ideas?

thanks a lot

[borisz]

Hi!

Max voltage which can be measured on analog port is 3,3V.
Isolating analog voltages is not as simple as digital. For protection you can add 3,3V zener diode connected between pin which you will use and GND. Add also 100 ohm resistor from your pin to signal.

regards

Boris