# wx.writeBLECharacteristicValue(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

Writes binary data to a Bluetooth low-power device characteristic value. Note: Features of the device must support write Before it can be successfully invoked.

# parameter

# Object object

attribute type Default values Required Introductions
deviceId string yes Bluetooth Device id
serviceId string yes Bluetooth Feature Corresponding Service UUID
characteristicId string yes Bluetooth characteristic UUID
value ArrayBuffer yes Binary Values for Bluetooth Device Features
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.
初始值 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

  • Multiple parallel calls have the possibility of write failure.
  • Mini Programs do not limit the size of the packet to be written, but the system and Bluetooth devices will limit Bluetooth 4.0 Single transmission data size, more than the maximum number of bytes will occur after the write error, it is recommended that each write no more than 20 Bytes.
  • If a single write of data is too long, iOS There are situations on the system where there will be no callbacks (including error callbacks).
  • On Android, after calling wx.notifyBLECharacteristicValueChange This interface is invoked immediately after success, which can occur on some models 10008 System error

# sample code

Preview with Developer Tool

// Send a 0x00 hexadecimal data to a Bluetooth device
let buffer = new ArrayBuffer(1)
let dataView = new DataView(buffer)
dataView.setUint8(0, 0)

  // Here. deviceId Need to getBluetoothDevices or onBluetoothDeviceFound Get in interface
  // Here. serviceId Need to getBLEDeviceServices Get in interface
  // Here. characteristicId Need to getBLEDeviceCharacteristics Get in interface
  // The value here is the ArrayBuffer type
  value: buffer,
  success (res) {
    console.log('writeBLECharacteristicValue success', res.errMsg)