Question

对于使用BLE（蓝牙低功耗）的Android应用程序，我正在尝试使用evothings插件订阅心率测量的混合设备通知。可以扫描设备，连接读出服务但无法订阅。

以下是一些代码片段：

app.connect = function(address, name)
{
    app.stopLeScan();
    console.log('connect('+address+')');
    document.getElementById('deviceName').innerHTML = address + " " + name;
    ble.connect(address, function(r)
    {
        app.deviceHandle = r.deviceHandle;
        console.log('connect '+r.deviceHandle+' state '+r.state);
        document.getElementById('deviceState').innerHTML = r.state;
        if (r.state == 2) // connected
        {
            console.log('connected, requesting services...');
            app.getServices(r.deviceHandle);
            app.subscribe(r.deviceHandle);
        }


    }, function(errorCode)
    {
        console.log('connect error: ' + errorCode);
    });
};

订阅功能：

app.subscribe = function(deviceHandle)
{

    console.log('Write Descriptor..');
    ble.writeDescriptor(deviceHandle,
        "00002a37-0000-1000-8000-00805f9b34fb", // Characteristic
        "00002902-0000-1000-8000-00805f9b34fb", // descriptor
        new Uint8Array([1,0]),
        function()
        {
            console.log('Status: writeDescriptor ok.');
        },
        function(errorCode)
        {
            // This error will happen on iOS, since this descriptor is not
            // listed when requesting descriptors. On iOS you are not allowed
            // to use the configuration descriptor explicitly. It should be
            // safe to ignore this error.
            console.log('Error: writeDescriptor: ' + errorCode + '.');
        });

    console.log('Subscribe..');
    ble.enableNotification(deviceHandle,
        "00002a37-0000-1000-8000-00805f9b34fb",
        function(data)
        {
            console.log('byteLength: '+data.byteLength);
        },
        function(errorCode)
        {
            console.log('Error: enableNotification: ' + errorCode + '.');
    });

}

日志的输出显示以下内容：

Write Descriptor.. index.js:44
Subscribe.. index.js:62
connected, requesting services... index.js:211
Error: enableNotification: JSON error. index.js:71
Status: writeDescriptor ok. index.js:51
s1: 0 00001800-0000-1000-8000-00805f9b34fb. 2 chars. index.js:231
 c11: 00002a00-0000-1000-8000-00805f9b34fb. 0 desc. index.js:248
  properties: PROPERTY_READ index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250
 c12: 00002a01-0000-1000-8000-00805f9b34fb. 0 desc. index.js:248
  properties: PROPERTY_READ index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250
s2: 0 00001801-0000-1000-8000-00805f9b34fb. 1 chars. index.js:231
 c13: 00002a05-0000-1000-8000-00805f9b34fb. 1 desc. index.js:248
  properties: PROPERTY_INDICATE index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250
  d26: 00002902-0000-1000-8000-00805f9b34fb index.js:268
s3: 0 0000180d-0000-1000-8000-00805f9b34fb. 3 chars. index.js:231
 c14: 00002a37-0000-1000-8000-00805f9b34fb. 1 desc. index.js:248
  properties: PROPERTY_NOTIFY index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250
  d27: 00002902-0000-1000-8000-00805f9b34fb index.js:268
 c15: 00002a38-0000-1000-8000-00805f9b34fb. 0 desc. index.js:248
  properties: PROPERTY_READ index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250
 c16: 00002a39-0000-1000-8000-00805f9b34fb. 0 desc. index.js:248
  properties: PROPERTY_WRITE index.js:249
  writeType: WRITE_TYPE_DEFAULT index.js:250

我对作为s3列出的炉灶率服务感兴趣。但启用通知会导致JSON错误。我希望有人能给出一些指示。

提前致谢

Maverick2k

Answer 1

您似乎正在使用图书馆＆＃34; easyble＆＃34;来自evothings-例子。我是对的吗？

此外，功能＆＃34; app.getServices＆＃34;未在您的示例中列出，但似乎在您致电＆＃34;订阅＆＃34;之前无法完成。因此，在＆＃34; subscribe＆＃34;期间，UUID和特征和描述符的句柄不可用，并且任何使用它们的尝试都会失败。

我不知道＆＃34; writeDescriptor＆＃34;在这种情况下可能会成功;也许它的错误处理会以某种方式破坏。

无论如何，拨打电话＆＃34;订阅＆＃34;在＆＃34; getServices＆＃34;的最后打回来。这应该可以解决你的问题。

订阅带有evothings插件的BLE通知

1 个答案: