Extra Inputs with Interrupts
Posted: Fri Feb 07, 2014 2:06 pm
I'm building a board that will house 30 lighted buttons. So I'll need to have 30 digital inputs and 30 digital outputs. I've seen where people have used the MCP23017 for i2c, or another similar chip for spi. My question though, is do we have the ability to use interrupts to detect a press using either of these methods? It seems wasteful to constantly poll all the buttons all the time.
I've tried to research this already, and I'm finding completely different answers everywhere. I understand that the situation has evolved over time, but I'm having a hard time figuring out where we are now. Or perhaps there's a better solution than what I'm looking at altogether? What do you guys think?
I've tried to research this already, and I'm finding completely different answers everywhere. I understand that the situation has evolved over time, but I'm having a hard time figuring out where we are now. Or perhaps there's a better solution than what I'm looking at altogether? What do you guys think?