EMC2101 Fan Controller and Temperature sensor¶
emc2101 component allows you to control a cooling fan from ESPHome (datasheet). It also provides temperature
sensors and a tachometer. The fan can be controlled either by a PWM signal or by outputing a DC voltage
using its DAC.
The I²C Bus is required to be set up in your configuration for this sensor to work.
# Example configuration entry emc2101: pwm: resolution: 8
address (Optional, int): Manually specify the I²C address of the sensor. Defaults to
inverted (Optional, boolean): Inverts the output so 0 means 100% duty cycle and 1 means 0%. Defaults to
pwm (Optional): Enable PWM output.
resolution (Optional, int): Determines effective resolution and the frequency of the PWM signal. Defaults to
divider (Optional, int): Value for the frequency divider. Defaults to
dac (Optional): Enable DAC output.
conversion_rate (Optional, string): The number of digital to analog conversions perfomed per second. One of
32. Defaults to
The PWM signal frequency is determined by the following formula:
And the PWM resolution, the steps in the duty cycle, is calculated by the following formula:
So, with the default values the PWM signal will have a frequency of 7.83KHz and a resolution of 2.17%. The maximum
resolution value is
31 which will configure a frequency of 5.81KHz with a resolution of 1.61%.
output: - platform: emc2101 id: fan_duty_cycle
id (Required, ID): The ID to use for code generation, and for reference by dependent components.
When using the
emc2101 output with a Speed Fan it is advised to configure the speed_count
as twice the resolution so the number of speeds in the fan matches the number of steps in the fan controller.
sensor: - platform: emc2101 internal_temperature: id: internal_temperature_sensor name: "Internal Temperature Sensor" speed: id: speed_sensor name: "Speed Sensor" duty_cycle: id: duty_cycle_sensor name: "Duty Cycle Sensor" update_interval: 5s
internal_temperature (Optional): The internal temperature sensor. All options from Sensor.
external_temperature (Optional): The external temperature sensor. More accurate but it needs an additional transistor to be installed. All options from Sensor.
speed (Optional): The fan speed sensor in RPMs. All options from Sensor.
duty_cycle (Optional): Duty cycle sensor. All options from Sensor.
update_interval (Optional, Time): The interval to check the sensor. Defaults to