如何从ble设备android读取数据？

Question

我开发了具有写功能的应用程序。写入功能可以正常工作，但是读取功能无法从BLE设备获得价值，或者我不知道如何获得价值。我想获得此值“ 7B 1E 01 7D 8D 0A”。但是我得到了这个“ 87”。我不知道我在哪里做错了。

这是代码。

@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
            super.onCharacteristicRead(gatt, characteristic, status);
            Log.e("onCharacteristicRead", "Status: " + status);
            if (Constant.DEBUG) {
                if (status == 0) {
                    Log.i("JMG", "Read from:" + characteristic.getUuid().toString() + " value: " + bytesToString(characteristic.getValue()));
                } else {
                    Log.i("JMG", "Read fail ,characteristic uuid=:" + characteristic.getUuid().toString() + " status=" + status);
                }
            }
            Log.e("JMG 1", "Read from:" + characteristic.getUuid().toString() + " value: " + bytesToString(characteristic.getValue()));
            String value = Arrays.toString(characteristic.getValue());
            Log.e("JMG 2", "Read From" + characteristic.getUuid().toString() + "Value" + value);
            Intent intent = new Intent(READ_SUCCESS);
            intent.putExtra(EXTRA_CHARACTERISTIC, characteristic.getUuid().toString());
            intent.putExtra(EXTRA_VALUE, characteristic.getStringValue(0));
            intent.putExtra(EXTRA_VALUE_BYTE_ARRAY, characteristic.getValue());
            mContext.sendBroadcast(intent);
            //COMMENT CODE 
            /*intent.putExtra(EXTRA_VALUE_STRING, bytesToString(characteristic.getValue()));
            intent.putExtra(EXTRA_VALUE, characteristic.getStringValue(0));
            intent.putExtra(EXTRA_VALUE_BYTE_ARRAY, bytesToHex(characteristic.getValue()));*/

        }