Because the multiplexer can also process digital signals, you can use it to transfer TTL-level serial data to multiple devices through pipe or transfer from multiple devices. Drive it to a high level, and it will completely disconnect the common pins (all switches are disconnected). It is suitable for digital and analog signals (voltage cannot be higher than VCC) and can be connected in either direction. To control this, connect the four digital outputs to the address pin of the chip (SO-S3) and send it the binary address of the channel. This is a convenient 16 channel CD74HC4067 analog/digital multiplexer/demultiplexer. The internal switch is bidirectional, with a low on resistance and off leakage, and to prevent talk, turn off the switch first and then on. Colour: blue Material: PCB Package Contents: 10 * CD74HC4067 Analog Multiplexer Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.