GY-63_MS5611/libraries/HC4051

HC4051

HC4051 is an Arduino library for a HC4051 1x8 channel multiplexer.

Description

HC4051 is a library to control the CD74HC4051 8 channel multiplexer / demultiplexer and compatible devices.

The HC4051 allows e.g one analog port read up to 8 different analog channels, or one digital port to read the state of 8 buttons.

It is also possible to use the HC4067 to select an OUTPUT channel. The signal pin can be connected to VCC (5V) or an IO pin set to OUTPUT. Only the selected channel can show the HIGH level of the IO pin if set to HIGH. Not selected pins will all be set to LOW.

The channel selection is done with four select lines A, B, C

The device can be enabled/disabled by the enable line INH

Compatibles

To elaborate.

Related

• https://github.com/RobTillaart/HC4051 (1x8 mux)
• https://github.com/RobTillaart/HC4052 (2x4 mux)
• https://github.com/RobTillaart/HC4053 (3x2 mux)
• https://github.com/RobTillaart/HC4067 (1x16 mux)
• https://github.com/RobTillaart/MAX14661 (2x16 mux, I2C)
• https://tronixstuff.com/2013/08/05/part-review-74hc4067-16-channel-analog-multiplexerdemultiplexer/

Hardware connection

Typical connection is to connect the three select pins to four IO pins of your board.

The optional enablePin (INH) must be connected to GND if not used. This way the device will be continuous enabled.

Example multiplexing analog in.

        processor                      HC4051
     +-------------+              +-------------+
     |             |              |             |
     |           A |------------->| S0       Y0 |
     |           B |------------->| S1       Y1 |
     |           C |------------->| S2       Y2 |
     |             |              |          Y3 |
     |          E  |------------->| INH      Y4 |
     |             |              |          Y5 |
     |         A0  |<-------------| Y        Y6 |
     |             |              |          Y7 |
     |         GND |--------------| GND      Y8 |
     |             |              | VCC         |
     |             |              |             |
     +-------------+              +-------------+

Less Select lines

Note: the library does not meant for this mode, although it should work. The GND-ed pins should be set to 255 (not tested).

It is possible to use less IO pins to connect to the S0..S3. The ones not connected to an IO pin must be connected to GND (preferred).

S0	S1	S2	pins	notes
IO	IO	IO	0-7	default usage
IO	IO	GND	0-3
IO	GND	GND	0-1

Of course it is possible to set a Select pin to VCC instead of GND. This will result in another subset of the Y pins to select from.

Interface

#include "HC4051.h"

Core

• HC4051(uint8_t A, uint8_t B, uint8_t C, uint8_t enablePin = 255) constructor. Set the three select pins and optional the enable pin. If the enablePin == 255 it is considered not used.
• void setChannel(uint8_t channel) set the current channel. Valid values 0..7, this value is not checked, only the lower 3 bits will be used.
• uint8_t getChannel() returns the current channel 0..7. The selected channel is also returned when the multiplexer is disabled.

Enable

These functions work only if enablePin is set in the constructor.

• void enable() enables the HC4051 to multiplex.
• void disable() disables the HC4051, no channel is selected.
• bool isEnabled() returns the current status of the HC4067. Also returns true if the enablePin is not set in the constructor.

Future

• keep in sync with HC4067 et.al.

Support

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Thank you,