Android从蓝牙数据中获取byteValue

Question

读取蓝牙传感器特性时，值或测量值存储在特性值中。我怎样才能得到这样的字节值:

00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00

来自传感器值？

/******** 编辑 ***********/

@Vikram 推荐以下内容:

        private void updateAdc3Values(BluetoothGattCharacteristic characteristic) {

        // Convert values if needed
        //double adc3 = SensorTagData.extractAdc3(characteristic);


/******** Used to get raw HEX value ********/   

        byte[] ADCValue3 = characteristic.getValue();
        String adc3Hex = ADCValue3.toString()
                .replace("[", "")   //remove the right bracket
                .replace("]", ""); //remove the left bracket

//      Log.e("ADC3", "ADC CH3 characteristicvalue from TEST is " + adc3Hex);
//      Log.i("ADC3", "ADC Last 6CH3 characteristicvalue from TEST is " + adc3Hex.substring(adc3Hex.length() - 6));  //Prints last 6 of this string

        // Get UUID
        String ch3 = (String.valueOf(characteristic.getUuid()));
        String ch3UUID = ch3.substring(0, Math.min(ch3.length(), 8));
//      Log.d("ADC3", "ADC FIRST 6CH3 characteristicvalue from TEST is " + ch3.substring(0, Math.min(ch3.length(), 8)));  //Print first 6 of this string


        String adc3hex6 = adc3Hex.substring(adc3Hex.length() - 6);

        StringBuilder sb = new StringBuilder(); 
        for (byte b : ADCValue3) { 
            if (sb.length() > 0) { 
                sb.append(':'); 
                } 
        sb.append(String.format("%02x", b)); }


        Log.w("ADC3", "StringBuilder " + sb);

/********  Used to get raw HEX value   ********/        


    }

我基本上一直在使用不同类型的输出，来试验所有的可能性。使用 byte[] 特征值，我形成了不同类型的输出。忽略 UUID，这只是我们证明这些值来自正确的 channel 。所以我只是分割 UUID 以获得前 6 个字符，这证明了它来自的 channel 。

在上述情况下，Log.i 以 ADC3 字节数组值开头，此行记录一次测量值:

B@42bc0738

然后是StringBuilder之后的姊妹日志:

7a:17:d0:7f:ff:ff:21:b4:e1:80:00:00:a4:a6:f4:77:73:5e

这似乎是我正在寻找的正确格式和值。现在是时候比较这些值了。

Answer 1

转自评论:

OP 正在从 BluetoothGattCharacteristic#getValue() 方法获取 byte[]。

要以所需格式格式化代码，请使用以下代码段:

// Use StringBuilder so that we can go through the byte[] 
// and append formatted text
StringBuilder sb = new StringBuilder(); 

for (byte b : byteArray) { 
    if (sb.length() > 0) { 
        sb.append(':'); 
    } 

    sb.append(String.format("%02x", b)); 
}