I built a simple clock using a 4 digits 7 segments LCD display. I display one digit at a time, switching on and off very quicky and cycling through digits.
Everything is ok, but I used 8 + 4 = 12 arduino pins. I need 2 more pins for other features and I don't want to use 0 and 1 as I need onboard programming features of Arduino Mini.
I used I2C for RTC clock, I could add some interface here (like a PCF8574) and get some pins from here. But I'd like a different (and more educational, for me) approach.
Is there an IC that sends an HIGH output on one of four output pins driven by 2 input pins? I need this:
IN OUT P0 P1 D0 D1 D2 D3 0 0 1 0 0 0 0 1 0 1 0 0 1 0 0 0 1 0 1 1 0 0 0 1
This way I can connect OUT to digit selection and spare 2 pins.
Thanks for your hints.