# Sensor

# Interface Declaration

{ "name": "system.sensor" }

# Import Module

import sensor from '@system.sensor' 
// or 
const sensor = require('@system.sensor')

# Interface Definition

# Methods

# sensor.subscribePressure(OBJECT)

Listens for pressure sensor data. If called multiple times, only the last call takes effect.

# Parameters:

Parameter	Type	Required	Description
callback	Function	Yes	Callback triggered each time the pressure information changes.

# Callback Return Value:

Parameter	Type	Description
pressure	Number	Pressure, in hPa (hectopascals), floating-point number.

# Example:

sensor.subscribePressure({
  callback: function(ret) {
    console.log(`handling callback, pressure = ${ret.pressure}`)
  }
})

# sensor.unsubscribePressure()

Cancels listening for pressure sensor data.

# Parameters:

None

# Example:

sensor.unsubscribePressure()

# sensor.subscribeAccelerometer(OBJECT)

Listens for accelerometer sensor data.

# Parameters:

Parameter	Type	Required	Description
interval	String	No	Frequency of callback execution for accelerometer data listening. Default is 'normal'.
callback	Function	Yes	Callback triggered when gravity sensor data changes.
fail	Function	No	Callback for subscription errors.

# Valid Values for interval:

Value	Description
game	Suitable for game update callback frequency, around 20ms per call.
ui	Suitable for UI update callback frequency, around 60ms per call.
normal	Normal callback frequency, around 200ms per call.

# Callback Return Value:

Parameter	Type	Description
x	Number	X-axis coordinate.
y	Number	Y-axis coordinate.
z	Number	Z-axis coordinate.

# Example:

sensor.subscribeAccelerometer({
  callback: function(ret) {
    console.log(`handling callback, x = ${ret.x}, y = ${ret.y}, z = ${ret.z}`)
  },
  fail: function(msg, code) {
    console.log(`handling callback, fail:`, msg, code)
  }
})

# sensor.unsubscribeAccelerometer()

Cancels listening for accelerometer sensor data.

# Parameters:

None

# Example:

sensor.unsubscribeAccelerometer()

# sensor.subscribeCompass(OBJECT)

Listens for compass data. If called multiple times, only the last call takes effect.

# Parameters:

Parameter	Type	Required	Description
callback	Function	Yes	Callback triggered when compass data changes.
fail	Function	No	Callback for subscription failure.

# Callback Return Value:

Parameter	Type	Description
direction	Number	Represents the angle between the device's y-axis and the Earth's magnetic north pole. When facing north, the angle is 0; facing south, it is π; facing east, it is π/2; facing west, it is -π/2.
accuracy	Number	Accuracy, see compass accuracy description for details.

# Error Codes for fail:

Error Code	Description
1000	The current device does not support the compass sensor.

# Example:

sensor.subscribeCompass({
  callback: function (res) {
    console.log(`handling subscribeCompass callback, direction = ${res.direction}, accuracy = ${res.accuracy}`)
  },
  fail: function (data, code) {
    console.log(`handling subscribeCompass fail, code = ${code}`)
  }
})

# sensor.unsubscribeCompass()

Cancels listening for compass data.

# Parameters:

None

# Example:

sensor.unsubscribeCompass()

# Compass Accuracy Description:

Value	Description
3	High accuracy.
2	Medium accuracy.
1	Low accuracy.
-1	Unreliable, sensor disconnected.
0	Unreliable, reason unknown.

# Support Details

Interface	Supported Device Products	Unsupported Device Products
subscribePressure	Xiaomi Watch S3, Xiaomi Band 9 Pro, Xiaomi Band 10, Xiaomi Watch S4	Xiaomi S1 Pro Sports Health Watch, Xiaomi Band 8 Pro, Xiaomi Band 9, Redmi Watch 4, Xiaomi Watch H1, REDMI Watch 5
unsubscribePressure	Xiaomi Watch S3, Xiaomi Band 9 Pro, Xiaomi Band 10, Xiaomi Watch S4	Xiaomi S1 Pro Sports Health Watch, Xiaomi Band 8 Pro, Xiaomi Band 9, Redmi Watch 4, Xiaomi Watch H1, REDMI Watch 5
subscribeAccelerometer	Xiaomi Band 9 / 9 Pro, Xiaomi Band 10	Xiaomi Watch S3, Xiaomi S1 Pro Sports Health Watch, Xiaomi Band 8 Pro, Redmi Watch 4, Xiaomi Watch H1, Xiaomi Watch S4, REDMI Watch 5
unsubscribeAccelerometer	Xiaomi Band 9 / 9 Pro, Xiaomi Band 10	Xiaomi Watch S3, Xiaomi S1 Pro Sports Health Watch, Xiaomi Band 8 Pro, Redmi Watch 4, Xiaomi Watch H1, Xiaomi Watch S4, REDMI Watch 5
subscribeCompass / unsubscribeCompass	Xiaomi Watch S4, REDMI Watch 5	Other Xiaomi band and watch devices

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