16 Channel Analog Multiplexer
Multiplexer Module is a micro chip that requires 1 Analog Pin and 2 to 4 Digital Pins to allow the micro controller to monitor more Analog Pins for sensor readings. The requirement of 1 Analog Pin is actually the output pin shared among all the extension Analog Pins. The module only allow 1 Analog channel or sensor value to be connected to the output Analog Pin each at a time thus they take turns to operate.
74HC4067 16-Channel Analog Digital Multiplexer Breakout Board Module
The 74HC4067 can operate on voltages between 2 and 6V DC, which allows use with 3.3V and 5V micro-controllers and boards such as Arduino and Raspberry Pi.
This chip is like a rotary switch – it internally routes the common pin (COM in the schematic, SIG on the board) to one of 16 channel pins (CHANxx).
It works with both digital and analog signals (the voltage can’t be higher than VCC), and the connections function in either direction.
To control it, connect 4 digital outputs to the chip’s address select pins (S0-S3), and send it the binary address of the channel you want .
This allows to connect up to 16 sensors to your system using only 5 pins!
Since the mux/demux also works with digital signals, it can be used to pipe TTL-level serial data to or from multiple devices.
The internal switches are bidirectional, support voltages between ground and VCC, have low “on” resistance and low “off” leakage, and to prevent crosstalk, perform “break-before-make” switching.
The board also breaks out the chip’s “enable” pin, which when driven high, will completely disconnect the common pin (all switches “off”).
- SIG Analog pin to A0 of NodeMCU
- S0 Digital pin to D0 of NodeMCU
- Digital pin to D1 of NodeMCU
- S2 Digital pin to D2 of NodeMCU
- S3 Digital pin to D3 of NodeMCU
- EN Digital pin & Ground of NodeMCU
- Gnd Power Supply pin to Ground of NodeMCU
- VCC Power Supply pin to 5V of NodeMCU base
- C0 to C15 will be analog input pins can be defined by user
- 1 X 16 Channel Analog Multiplexer
- Chip set: CD74HC4067
- Channels: 16
- Address Lines: 4
- Supply: 2V to 6V
- On resistance: 70 Ohms @ 4.5V
- 6ns break-before-make @ 4.5V
- Temperature range: -55C to 125C
|Dimensions||4 × 1.8 × 0.1 cm|