# 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

# error

# 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)

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