MCP3008 8-Channel 10-Bit A/D Converter

The Microchip Technology Inc. MCP3008 devices are successive approximation 10-bit Analog-to-Digital (A/D) converters with on-board sample and hold circuitry.

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Component/Hub

The MCP3008 component allows you to use MCP3008 8-Channel 10-Bit A/D Converter (datasheet, Adafruit) in ESPHome. It uses the SPI Bus for communication.

Once configured, you can use any of the 8 pins as sensors for your projects.

Each pin will respond with a voltage calculated off of the reference_voltage (default is 3.3V). It calculates the voltage by multiplying the reference_voltage by the value on the pin (basically the percentage of VREF).

Most configurations will establish the reference voltage by assigning it the value of VREF, which is located at pin 13 on the chip.

If you want just the scaled value you can use the read_data function:

float MCP3008::read_data(uint8_t pin)

# Example configuration entry
mcp3008:
  cs_pin: D8
  id: my_mcp

# Example config of sensors.
# This is a NTCB3950 10K thermocoupler attached to pin 0
# of the MCP3008 with a 10K resistor as a voltage divider.
# See `resistance` and `ntc` platorms for other options
sensor:
  - platform: mcp3008             # Attached to pin 0 of the MCP3008.
    reference_voltage: 3.19
    update_interval: 1s
    mcp3008_id: my_mcp
    id: freezer_temp_source
    number: 0                     # MCP3008 pin number
  - platform: resistance
    id: freezer_resistance_sensor
    sensor: freezer_temp_source
    configuration: DOWNSTREAM
    resistor: 10kOhm
  - platform: ntc
    id: freezer_temp
    sensor: freezer_resistance_sensor
    calibration:
      b_constant: 3950
      reference_temperature: 25°C
      reference_resistance: 10kOhm
    name: Freezer Temperature

Configuration variables:

  • id (Required, ID): The id to use for this MCP3008 component.

  • cs_pin (Required, int): The SPI cable select pin to use.

Sensor

The mcp3008 sensor allows you to use your MCP3008 10-Bit A/D Converter sensors with ESPHome. First, setup a MCP3008 Hub for your MCP3008 sensor and then use this sensor platform to create individual sensors that will report the voltage to Home Assistant.

Configuration variables:

  • mcp3008_id (Required, ID): The id of the parent MCP3008 component.

  • number (Required, int): The pin number of the MCP3008.

  • reference_voltage (Optional, float): The reference voltage. Defaults to 3.3V.

  • update_interval (Optional, Time): The interval to check the sensor. Defaults to 1s.

See Also