I'm the "software guy" but am trying to help out on the hardware side for a small project we have going on. It's fun, I like to learn new stuff. I'm currently working on a circuit that is connected to a piece of data acquisition hardware that provides 8 digital bits (1 port) and these 8 bits are wired up to a set of decoder ICs. Great, that all works fine. The problem is that I need ONE MORE digital bit to control a SSR - but I don't have any more available digital pins so I'm going to use one of the analog outputs on the DAQ hardware.
OK, finally my question: The analog out can be software controlled to output 0 - 10v. If I connect this straight to a logic pins this means that if someone screws up (people always do) they could fry things by accidentally sending 10v to a part that is expecting a maximum of 5v. I would like to add a little circuitry to cap the analog line at a max of 5v. I have NO IDEA how to do this and was hoping someone here could suggest a simple solution to cap a signal at a max of 5v.
Thanks for reading!