Since the multiplexer can also process digital signals, you can use it to transmit serial data at TTL level to multiple devices via tubes or transmit 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 must not be higher than VCC) and can be connected in both directions. To control this, connect the four digital outputs to the chip's address pins (SO-S3) and send the binary address to the channel. This is a practical 16-channel CD74HC4067 analog/digital multiplexer/demultiplexer. The internal switch is bidirectional, with low on-resistance and off-leakage, and to prevent crosstalk, turn off the switch first and then turn it on. Color: 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 picture to be slightly different from the real one. The allowed measurement error is +/- 1-3 cm.