MAX6956 I/O Expander¶

The MAX6956 component allows you to use MAX6956 I/O expanders (datasheet) in ESPHome. It uses I²C Bus for communication.

The max6956 exists in 2 versions 20 or 28 ports, depending on the packaging. Once configured, you can use any of the 20 or 28 pins for your projects. Within ESPHome they emulate a real internal GPIO pin and can therefore be used with many of ESPHome’s components such as the GPIO binary sensor or GPIO switch. Interrupt-on-change for inputs is not possible.

Pins can also be individualy configured as led driver and used with Light components. Current value can be set globaly or for each pin, through 16 possible levels. Driving RGB led requires 3 pins.

Any option accepting a Pin Schema can theoretically be used.

Component/Hub¶

../_images/max6956.jpg — MAX6956 I/O Expander.¶

The max6956 is an I²C Bus slave. Its address is configured using A0 and A1 hardware pins from 0x40 to 0x4F.

max6956:
  - id: max6956_1
    address: 0x40
    i2c_id: bus_a

Configuration variables:¶

id (Required, ID): The id to use for this max6956 component.
address (Optional, int): The I²C address of the driver. Defaults to 0x40.
i2c_id (Optional): The I²C Bus ID Defaults to false
brightness_global (Optional): Set the value of the current to be sink by all pins configured as led driver. Defaults to 0
brightness_mode (Optional): Define if the current to be sink will be confgured globaly or per pin configured as led driver. Defaults to global

Binary Sensor Example¶

max6956 pins can be use as binary sensor. Individual pullup are supported.

# Example configuration
binary_sensor:
  - platform: gpio
    name: "MaxIn Pin 4"
    id: In_4
    pin:
      max6956: max6956_1
      number: 4
      mode:
        input: true
        pullup: true
      inverted: False

Switch Example¶

max6956 pins can be use as switch.

# Example configuration
  switch:
    - platform: gpio
      name: "MaxIn Pin 8"
      id: In_8
      pin:
        max6956: max6956_1
        number: 8
        mode:
          output: true
        inverted: False

Led driver Example¶

max6956 can control a constant-current sink to drive leds, with 16 equal steps from 1.5mA to 24mA.

# Example configuration : pin as led driver, current globaly
i2c:
  id: bus_a
  sda: GPIOXX
  scl: GPIOXX

switch:
  - platform: template
    name: "Led"
    id: MaxOut4
    optimistic: true
    turn_on_action:
      - output.turn_on: maxOut_pin4
    turn_off_action:
      - output.turn_off: maxOut_pin4

number:
  - platform: template
    name: "Global brightness"
    id: global_brightness
    optimistic: true
    min_value: 0
    max_value: 15
    initial_value: 1
    step: 1
    mode: slider
    on_value:
      - max6956.set_brightness_global:
          id: max6956_1
          brightness_global: !lambda return x;

max6956:
  - id: max6956_1
    address: 0x40
    i2c_id: bus_a
    brightness_mode: global
    brightness_global: 5

#output to use
output:
  - platform: max6956
    pin: 4
    id: maxOut_pin4

#led binded to output
light:
  - platform: monochromatic
    id: Light_1
    output: maxOut_pin4

# Example configuration : pin as led driver, current managed individualy (RBG led)
i2c:
  id: bus_a
  sda: GPIOXX
  scl: GPIOXX

max6956:
  - id: max6956_1
    address: 0x40
    i2c_id: bus_a
    brightness_mode: segment

switch:
  - platform: template
    name: "Led Red"
    id: MaxOut4
    optimistic: true
    turn_on_action:
      - output.turn_on: maxOut_pin4
    turn_off_action:
      - output.turn_off: maxOut_pin4

  - platform: template
    name: "Led Green"
    id: MaxOut5
    optimistic: true
    turn_on_action:
      - output.turn_on: maxOut_pin5
    turn_off_action:
      - output.turn_off: maxOut_pin5

  - platform: template
    name: "Led Blue"
    id: MaxOut6
    optimistic: true
    turn_on_action:
      - output.turn_on: maxOut_pin6
    turn_off_action:
      - output.turn_off: maxOut_pin6

number:
  - platform: template
    name: "Number Red"
    id: number_LedRed
    optimistic: true
    min_value: 0
    max_value: 100
    initial_value: 10
    step: 1
    mode: slider
    on_value:
      - output.set_level:
          id: maxOut_pin4
          level: !lambda return x/100;

  - platform: template
    name: "Number Green"
    id: number_LedGreen
    optimistic: true
    min_value: 0
    max_value: 100
    initial_value: 10
    step: 1
    mode: slider
    on_value:
      - output.set_level:
          id: maxOut_pin5
          level: !lambda return x/100;

  - platform: template
    name: "Number Blue"
    id: number_LedBlue
    optimistic: true
    min_value: 0
    max_value: 100
    initial_value: 10
    step: 1
    mode: slider
    on_value:
      - output.set_level:
          id: maxOut_pin6
          level: !lambda return x/100;
output:
  - platform: max6956
    pin: 4
    id: maxOut_pin4
  - platform: max6956
    pin: 5
    id: maxOut_pin5
  - platform: max6956
    pin: 6
    id: maxOut_pin6

light:
  - platform: rgb
    id: Light_1
    default_transition_length: 0.1s
    gamma_correct: 1
    red: maxOut_pin4
    green: maxOut_pin5
    blue: maxOut_pin6

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