# wx.notifyBLECharacteristicValueChange(Object object)

Start from base library version 1.1.0. Please remaining backward compatible.

with Promise style call: Supported

Mini Program plugin: Support, need to Mini Program base library version no less than 1.9.6

Enables a Bluetooth low-power device when its eigenvalue changes notify Features, subscription features. Note: Features of the device must support notify or indicate Before it can be successfully invoked.

Also, you must first enable wx.notifyBLECharacteristicValueChange To listen to the device. characteristicValueChange event

# parameter

# Object object

attribute	type	Default values	Required	Introductions	Minimum version
deviceId	string		yes	Bluetooth Device id
serviceId	string		yes	Bluetooth Feature Corresponding Service UUID
characteristicId	string		yes	Bluetooth characteristic UUID
state	boolean		yes	Enable notify
type	string	indication	no	Sets the characteristic subscription type with a valid value of `notification` and `indication`	2.4.0
success	function		no	Interface calls the successful callback function
fail	function		no	Interface calls failed callback functions
complete	function		no	Callback function at the end of an interface call (both successful and unsuccessful calls are executed)

# error

Error code	Error message	Introductions
0	ok	normal
-1	already connect	Connected
10000	not init	Uninitialized Bluetooth adapter
10001	not available	The current Bluetooth adapter is not available
10002	No device	Specified device not found
10003	connection fail	Connection failure
10004	No service	Specified service not found
10005	No characteristic	Did not find the specified signature.
10006	No connection	Current connection disconnected
10007	property not support	Current feature does not support this operation
10008	system error	All other system reported anomalies
10009	system not support	Android System specific, system version below 4.3 Not supported WAS
10012	operate time out	Connection Timeout
10013	invalid_data	Connect deviceId Is empty or incorrectly formatted

# Be careful

Requires the device to actively update features after a successful subscription operation Value will trigger wx.onBLECharacteristicValueChange Callback.
On Android platform, call immediately after this interface is successfully invoked wx.writeBLECharacteristicValue Interface, which occurs on some models 10008 System error

# sample code

Preview with Developer Tool

wx.notifyBLECharacteristicValueChange({
  state: true, // Enable notify function
  // Here. deviceId Need has passed createBLEConnection Establish a link with the corresponding device
  deviceId,
  // Here. serviceId Need to getBLEDeviceServices Get in interface
  serviceId,
  // Here. characteristicId Need to getBLEDeviceCharacteristics Get in interface
  characteristicId,
  success (res) {
    console.log('notifyBLECharacteristicValueChange success', res.errMsg)
  }
})