CFSensor XGZP68xx Non-C Series Differential Pressure Sensor

CFSensor makes multiple generations of sensors with identical model numbers such as the 6899D or 6897D, but unfortunately with completely different I²C interfaces. You can identify which from the part number:

XGZP6897Dxxxxxxxx is the non-C series, which this component supports.
XGZP6897DCxxxxxxxx is the C series, which this component does NOT support.

Another way of telling the difference is the I²C address:

If the device is one of the non-C series, it appears at I²C address 0x6d.
If the device is one of the C series, it appears at I²C address 0x58.

Unfortunately CFSensor have removed from their website the datasheets for the non-C series of sensors. You will need to specifically find the older datasheet from another source. The v3.1 or later datasheets from CFSensor describe the C series which is a completely different device even though it has an identical model number to the <= v3.0 device.

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XGZP6897D Differential Pressure Sensor. (Credit: CFSensor, image cropped and compressed)

To use the sensor, set up an I²C Bus and connect the sensor to the specified pins.

# Example configuration entry
# It uses a filter offset to calibrate the sensor
sensor:
  - platform: xgzp68xx
    k_value: 16384
    temperature:
        name: "Temperature"
    pressure:
        name: "Differential Pressure"
        oversampling: "32768x"
        filters:
            - offset: 40.5

Configuration variables

temperature (Optional): All options from Sensor.
pressure (Optional): All options from Sensor.
- oversampling (Optional): One of 256x, 512x, 1024x, 2048x, 4096x, 8192x, 16384x, 32768x. It is not possible to disable oversampling. If not specified, this defaults to 4096x.
k_value (Optional, int): The K value comes from the list below. It will default to 4096 if not specified.
update_interval (Optional, Time): The interval to check the sensor. Defaults to 60s.

Usage

The sensors come in a series of pressure ranges. The now hard to find datasheet lists a table of pressure ranges to k_value, which you will need to set in your configuration:

-0.5 kPa to +0.5 kPa (k_value = 16384)
-1 kPa to +1 kPa (k_value = 8192)
-2.5 kPa to +2.5 kPa (k_value = 2048)
-5 kPa to +5 kPa (k_value = 1024)
-10 kPa to +10 kPa (k_value = 512)
-50 kPa to +50 kPa (k_value = 128)

On power up, the sensor will read an offset. You will need to calibrate the sensor which can be done by checking the value that is returned when the ports are open to the air. You can use the offset option to correct the reading. For example, if your sensor is reading -40Pa when the ports are disconnected, you can set the offset to 40.

If the sensor is running for a time, you will find that the zero point does drift after a while, especially if the sensor is used to detect pressure shocks. Designing in a way to periodically equalise the pressure between the ports so a new offset can be determined would be wise.