uniapp 或小程序，通过蓝牙连接设备， 给设备配网

1.打开蓝牙适配器

    openBluetoothAdapter() {
        const that = this
        wx.openBluetoothAdapter({
            success(res) {
                console.log('open blueFi success: ', res)
                that.onBluetoothDeviceFound()
                that.onBluetoothAdapterStateChange()
                that.startBluetoothDevicesDiscovery()
            },
            fail(error) {
                let errorRes = blueFi.fail(error)
                console.log(errorRes)
            }
        })
    },

2.打开蓝牙搜索功能

    startBluetoothDevicesDiscovery() {
        wx.startBluetoothDevicesDiscovery({
            services: UUIDS,
            success(res) {
                console.log("打开蓝牙搜索功能成功")
            }
        })
    }

3.监听寻找到新设备的事件

    onBluetoothDeviceFound() {
        const that = this
        wx.onBluetoothDeviceFound((res) => {
            var devices = res.devices;

            that.setData({
                devices: devices
            })
        })
    },

4.监听本机蓝牙状态变化的事件

onBluetoothAdapterStateChange() {
    wx.onBluetoothAdapterStateChange(function(res) {
        console.log('adapterState changed, now is', res)
    })
}

5.获取已发现的蓝牙设备 包括 已经和本机处于连接状态的设备

    getBluetoothDevices(){
    uni.getBluetoothDevices({
  success(res) {
    console.log(res)
    if (res.devices[0]) {
      console.log(ab2hex(res.devices[0].advertisData))
    }
  }
})
    }

6.获取特征值

getBLEDeviceCharacteristics(){
  uni.getBLEDeviceCharacteristics({
  // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接
  deviceId,
  // 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取
  serviceId,
  success(res) {
    console.log('device getBLEDeviceCharacteristics:', res.characteristics)
  }
})
}

7.开启订阅值

notifyBLECharacteristicValueChange(){
uni.notifyBLECharacteristicValueChange({
  state: true, // 启用 notify 功能
  // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接
  deviceId,
  // 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取
  serviceId,
  // 这里的 characteristicId 需要在 getBLEDeviceCharacteristics 接口中获取
  characteristicId,
  success(res) {
    var value = that.ab2hex(res.value); // ArrayBuffer转16进度字符串示例
    console.log('notifyBLECharacteristicValueChange success', res.errMsg)
  }
})
}

8. 连接设备

createBLEConnection(){
    uni.getBLEDeviceServices({
  // 这里的 deviceId 需要已经通过 createBLEConnection 与对应设备建立链接
  deviceId,
  success(res) {
    console.log('device services:', res.services)
   this.getBLEDeviceCharacteristics() //获取特征值
    setTimeout(function() {
	that.notifyBLECharacteristicValue() // 开启订阅
        let wifi = "chenKKK";
        let newWifi =  stringToUint8Array(wifi ) //  string 转化为 unit8array的函数
	that.writeBLECharacteristicValue('53',5,newWifi ) //发送写入数据	// 指令， 长度， 值 ， 这里根据设备的协议发				
  }, 2000)
  }
})
}

9.写入数据

	writeBLECharacteristicValue(typeNum,subCMD, data) {
		let that = this;
		let deviceId = this.bindDeviceMes.deviceId;
		let serviceId = this.bindDeviceMes.serviceId;
		let characteristicId = this.bindDeviceMes.writeId;
		var beffer = new ArrayBuffer(20)
		var bufView = new Uint8Array(beffer)
		bufView[0] = typeNum // 指令1
		bufView[1] = subCMD ? bufView[1] = subCMD : bufView[1] = data.length // 指令2
			for(let i = 0; i < 18; i++){ // 3-18位值（一共20，我这里不满20位补0）
				let item = data[i]
				if(!item){
					bufView[2+i] = 0
				}else{
					bufView[2 +i] = data[i]
				}
			}
		console.log('发送写入指令:' + String(bufView))
		// plus.bluetooth.writeBLECharacteristicValue({    //12.25更改
		uni.writeBLECharacteristicValue({
			// 这里的 deviceId 需要在 getBluetoothDevices 或 onBluetoothDeviceFound 接口中获取
			deviceId,
			// 这里的 serviceId 需要在 getBLEDeviceServices 接口中获取1
			serviceId,
			// 这里的 characteristicId 需要在 getBLEDeviceCharacteristics 接口中获取
			characteristicId,
			// 这里的value是ArrayBuffer类型
			value: beffer,
			success(res) {
				console.log('写入成功' + JSON.stringify(res))
				that.testList.push('写入数据成功' + JSON.stringify(res)) //test4
			},
			fail(res) {
				that.testList.push('写入数据失败' + JSON.stringify(res)) //test4
				console.log("写入数据失败" + res);
			}
		});
	},

10. 断开蓝牙连接

	closeBluetoothAdapter() {
		let that = this;
		that.reConnectNum = 0
		let deviceId = this.bindDeviceMes.deviceId;
		uni.closeBLEConnection({
			deviceId,
			success(res) {
				that.testList.push('断开蓝牙模块连接') //test4
			}
		})
		uni.closeBluetoothAdapter({
			success: res => {
				that.testList.push('断开蓝牙模块成功') //test4
				console.log('断开蓝牙模块成功');
			}
		});
		that.blueHadConnected = false;
	},

11.ArrayBuffer转16进度字符串示例 (接受蓝牙返回时使用)

function ab2hex(buffer) {
  const hexArr = Array.prototype.map.call(
    new Uint8Array(buffer),
    function (bit) {
      return ('00' + bit.toString(16)).slice(-2)
    }
  )
  return hexArr.join('')
}

12. 将string 转化为 unit8array的函数

const stringToUint8Array = function(string) {
	let pos = 0;
	const len = string.length;
	const out = [];
	let at = 0; // output position
	let tlen = Math.max(32, len + (len >> 1) + 7); // 1.5x size
	let target = new Uint8Array((tlen >> 3) << 3); // ... but at 8 byte offset
	while (pos < len) {
		let value = string.charCodeAt(pos++);
		if (value >= 0xd800 && value <= 0xdbff) {
			// high surrogate
			if (pos < len) {
				const extra = string.charCodeAt(pos);
				if ((extra & 0xfc00) === 0xdc00) {
					++pos;
					value = ((value & 0x3ff) << 10) + (extra & 0x3ff) + 0x10000;
				}
			}
			if (value >= 0xd800 && value <= 0xdbff) {
				continue; // drop lone surrogate
			}
		}
		// expand the buffer if we couldn't write 4 bytes
		if (at + 4 > target.length) {
			tlen += 8; // minimum extra
			tlen *= (1.0 + (pos / string.length) * 2); // take 2x the remaining
			tlen = (tlen >> 3) << 3; // 8 byte offset
			const update = new Uint8Array(tlen);
			update.set(target);
			target = update;
		}
		if ((value & 0xffffff80) === 0) { // 1-byte
			target[at++] = value; // ASCII
			continue;
		} else if ((value & 0xfffff800) === 0) { // 2-byte
			target[at++] = ((value >> 6) & 0x1f) | 0xc0;
		} else if ((value & 0xffff0000) === 0) { // 3-byte
			target[at++] = ((value >> 12) & 0x0f) | 0xe0;
			target[at++] = ((value >> 6) & 0x3f) | 0x80;
		} else if ((value & 0xffe00000) === 0) { // 4-byte
			target[at++] = ((value >> 18) & 0x07) | 0xf0;
			target[at++] = ((value >> 12) & 0x3f) | 0x80;
			target[at++] = ((value >> 6) & 0x3f) | 0x80;
		} else {
			// FIXME: do we care
			continue;
		}
		target[at++] = (value & 0x3f) | 0x80;
	}
	return target.slice(0, at);
}

13. unit8array转化为 string的方法

function Unit8ArrayToStr(array) {
    var out, i, len, c;
    var char2, char3;

    out = "";
    len = array.length;
    i = 0;
    while (i < len) {
        c = array[i++];
        switch (c >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                // 0xxxxxxx
                out += String.fromCharCode(c);
                break;
            case 12:
            case 13:
                // 110x xxxx 10xx xxxx
                char2 = array[i++];
                out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
                break;
            case 14:
                // 1110 xxxx 10xx xxxx 10xx xxxx
                char2 = array[i++];
                char3 = array[i++];
                out += String.fromCharCode(((c & 0x0F) << 12) |
                    ((char2 & 0x3F) << 6) |
                    ((char3 & 0x3F) << 0));
                break;
        }
    }

    return out;
}