我正在尝试开发一个android应用程序,它使用ble连接到我基于nrf51822的系统。其目的是将3字节值(rgb)写入我的自定义特性。
android是gatt客户端,基于nrf51的设备是gatt服务器。
我能成功地建立BLE连接并发现我的特点。
但是数据发送部分(setvalue)给我带来了麻烦。不管我写哪3个字节,在nrf51端都会得到相同的常量数据
下面是我的相关代码(Android)
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.d("BLENotifier", "BLE GAT : SERVICES DISCOVERED");
for(BluetoothGattService gs: gatt.getServices()) {
Log.d("BLENotifier", "SERVICE = " + gs.getUuid().toString());
}
//SELECT MY CHARACTERSTIC
ble_my_characterstic = gatt.getService(ble_service_uuid).getCharacteristic(ble_characterstic_uuid);
Log.d("BLENotifier", "BLE SELECTED CHARACTERSTIC " + ble_my_characterstic.getUuid().toString());
ble_connected = true;
}
public void writedata(String data){
//WRITE DATA TO MY CHARACTERSTIC
if(ble_my_characterstic != null && ble_connected == true){
my_gatt_handle.executeReliableWrite();
//ble_my_characterstic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
ble_my_characterstic.setValue(hexStringToByteArray(data));
my_gatt_handle.writeCharacteristic(ble_my_characterstic);
Log.d("BLENotifier", "BLE WRITE DATA " + data);
}
public static byte[] hexStringToByteArray(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
Log.d("BLENotifier", "hexStringToByteArray " + Integer.toString((int)data[0]) + " " + Integer.toString((int)data[1]) + " " + Integer.toString((int)data[2]));
return data;
}
我正在调用
writeData
方法作为ble_handle.writedata("0000FF")
这就是我在NRF51这边得到的
R = 4 | G = 239 | B= 1
谢谢
最佳答案
我真的很喜欢这个。不太确切的答案,但可以帮助你。
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status)
{
List<BluetoothGattService> services = gatt.getServices();
Log.i("onServicesDiscovered", services.toString());
keepConnect=services.get(3).getCharacteristics().get(0);
if(keepConnect!=null){
writeCharacteristic(gatt,keepConnect);
}
}
private void writeCharacteristic(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic)
{
byte[] byteData = hexToBytes("6fd362e40ebcd0945bf58dc4");
byte[] writeData = new byte[byteData.length];
for (int i = 0; i < byteData.length; i++) {
writeData[i] = byteData[i];
}
characteristic.setValue(writeData);
gatt.writeCharacteristic(characteristic);
}
public static byte[] hexToBytes(String hexRepresentation) {
int len = hexRepresentation.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(hexRepresentation.charAt(i), 16) << 4)
+ Character.digit(hexRepresentation.charAt(i + 1), 16));
}
return data;
}