Quote Originally Posted by tazntex View Post
After looking at http://www.rentron.com/PIC16F84.htm I thought I would try some experimenting with the serial I/O expander. Using a keypad to send the data with the [254] qualifier I am able to turn each relay on, however, I would like to be able to turn a relay on and hold it on while I am pressing the button on the keypad but as soon as I let go of the button I want the relay to turn off.
Hmm - Perhaps, if the keypad issues another serial command to tell the controller when a key has been released.