Now and again there’s a need to expand the I/O capabilities of your chosen micro controller, and instead of upgrading you can often use external parts to help solve the problem. One example of this is the 74HC4067 16-channel analog multiplexer demultiplexer.
That’s a mouthful – however in simple form it’s an IC that can direct a flow of current in either direction from one pin to any one of sixteen pins. Another way to think abou it is that you can consider the 74HC4067 to be a digital replacement to those rotary switches that allow you to select one of sixteen positions.
Don’t let that put you off, it’s just what we had in stock at the time. The part itself is available in through-hole and surface mount versions.
Using the 74HC4067
At this point you should download the data sheet, as we refer to it through the course of the article. The first thing to note is that the 74HC4067 can operate on voltages between 2 and 6V DC, which allows use with 3.3V and 5V microcontrollers and boards such as Arduino and Raspberry Pi. If for some reason you have the 74HCT4067 it can only work on 4.5~5.5V DC. Next – consider the pin out diagram from the data sheet:
Read More: Channel Analog Multiplexer Demultiplexer