Problem with advertising service uuids, and other server functionalities.

[roylee17]

Hi @raff ,

I'm currently integrating the goble (xpc, mostly) into gatt for MacOS support, I've got the client APIs unified (not completely done yet). But I'm having problem to get the server function work. It only broadcast name, but not service IDs. Any idea I can try?

xpc.Dict{
    "kCBMsgId":8,
     "kCBMsgArgs":xpc.Dict{
        "kCBAdvDataLocalName":"goble",
        "kCBAdvDataServiceUUIDs":[]string{"180f"}
    },
}

Thanks.
Roy

[raff]

I just checked in a fix. See goble.go.

The problem with Bluetooth via XPC (and the conversion from nodejs) it's
that is not really clear when things are strings, byte arrays or UUIDs, so
you just need to try until you get something that work :)

...actually, I wrote a 2 line program for nodejs, and run it as:

DEBUG=* node test.js

That dumps the messages, as close as they go "over the wire" and compared
with running goble in verbose mode it gives you an idea of what the
differences may be.

-- Raffaele

On Mon, Jan 26, 2015 at 11:17 PM, Tzu-Jung (Roy) Lee <
notifications@github.com> wrote:

Hi @raff https://github.com/raff ,

I'm currently integrating the goble (xpc, mostly) into gatt for MacOS
support, I've got the client APIs unified (not completely done yet). But
I'm having problem to get the server function work. It only broadcast name,
but not service IDs. Any idea I can try?

xpc.Dict{
"kCBMsgId":8,
"kCBMsgArgs":xpc.Dict{
"kCBAdvDataLocalName":"goble",
"kCBAdvDataServiceUUIDs":[]string{"180f"}
},
}

Thanks.
Roy

—
Reply to this email directly or view it on GitHub
#1.

[roylee17]

Thanks a lot!

Another XPC issue, please see below snippet for characteristic data - "kCBMsgArgData"

func (ble *BLE) SetServices(services []Service) {
    ble.sendCBMsg(12, nil) // remove all services
    arg := dict{
        "kCBMsgArgAttributeID":  1,
        "kCBMsgArgUUID":         []byte{0x18, 0x0F},
        "kCBMsgArgAttributeIDs": []int{},
        "kCBMsgArgType":         1,
        "kCBMsgArgCharacteristics": array{
            dict{
                "kCBMsgArgAttributeID":              2,
                "kCBMsgArgUUID":                     []byte{0x2A, 0x19},
                "kCBMsgArgAttributePermissions":     1,
                "kCBMsgArgCharacteristicProperties": 2,

                // hardcoded for static value, or leave nil for "read event(19)"       
                "kCBMsgArgData":                     []byte{0x64},

                "kCBMsgArgDescriptors": array{
                    dict{
                        "kCBMsgArgData": "Battery level between 0 and 100 percent",
                        "kCBMsgArgUUID": []byte{0x29, 0x01},
                    },
                    dict{
                        "kCBMsgArgData": []byte{4, 1, 39, 173, 1, 0, 0},
                        "kCBMsgArgUUID": []byte{0x29, 0x04},
                    },
                },
            },
        },
    }
    ble.sendCBMsg(10, arg) // Add Service
}

noble DEBUG output shows it left it null, instead of empty array/dict.

 bindings sendCBMsg: 10, {
  "kCBMsgArgAttributeID": 1,
  "kCBMsgArgAttributeIDs": [],
  "kCBMsgArgCharacteristics": [
    {
      "kCBMsgArgAttributeID": 2,
      "kCBMsgArgAttributePermissions": 1,
      "kCBMsgArgCharacteristicProperties": 2,
      "kCBMsgArgData": null,
      "kCBMsgArgDescriptors": [
        {
          "kCBMsgArgData": "Battery level between 0 and 100 percent",

I've tried a few hack as follow to treat the nil specially, but haven't got any work.

func valueToXpc(val r.Value) C.xpc_object_t {
        ...
    case r.Map:
        xv = C.xpc_dictionary_create(nil, nil, 0)
        for _, k := range val.MapKeys() {
            v := valueToXpc(val.MapIndex(k))
            if v == nil {
                log.Printf("XXXXXXXX:%s", k.String())
                // vv := C.xpc_array_create(nil, 0)
                // vv := C.xpc_data_create(unsafe.Pointer(0), C.size_t(0)
                // C.xpc_dictionary_set_data(xv, C.CString(k.String()), unsafe.Pointer(nil), C.size_t(0))
                // C.xpc_dictionary_set_value(xv, C.CString(k.String()), C.xpc_object_t(nil))
                // or simply skip...
                continue
            }
            C.xpc_dictionary_set_value(xv, C.CString(k.String()), v)
            if v != nil {
                C.xpc_release(v)
            }
        }

[roylee17]

I add some log in XpcConnection.cpp to see what's the final stuff passed to from node to XPC (or NULL value in the Dice are simply discarded).

diff --git a/src/XpcConnection.cpp b/src/XpcConnection.cpp
index 6d568cb..0819dfe 100644
--- a/src/XpcConnection.cpp
+++ b/src/XpcConnection.cpp
@@ -153,6 +153,11 @@ xpc_object_t XpcConnection::ObjectToXpcObject(v8::Handle<v8::Object> object) {
       v8::Handle<v8::Value> propertyValue = object->GetRealNamedProperty(propertyNameString);

       xpc_object_t xpcValue = XpcConnection::ValueToXpcObject(propertyValue);
+      if (xpcValue == NULL) {
+        NSLog(@"ROY: Set %s to NULL", *propertyNameStringValue);
+        xpc_dictionary_set_value(xpcObject, *propertyNameStringValue, NULL);
+        continue;
+      }
       xpc_dictionary_set_value(xpcObject, *propertyNameStringValue, xpcValue);
       if (xpcValue) {
         xpc_release(xpcValue);

According to the log, it seems that node passes NULL to XPC.

2015-01-28 14:51:12.417 node[27492:507] ROY: Set kCBMsgArgs to NULL
2015-01-28 14:51:12.418 node[27492:507] ROY: Set kCBMsgArgData to NULL

So I went back to try passing more different stuff from go to XPC. Still no luck so far.
Need more enlightenment.

// vv := C.xpc_dictionary_set_data(...)
// vv := C.xpc_dictionary_set_value(...)
// vv := C.xpc_null_create()
// vv := C.xpc_int64_create(0)
// vv := C.xpc_data_create(unsafe.Pointer(uintptr(0)), 0)
// ...
C.xpc_dictionary_set_value(xv, C.CString(k.String()), vv)

[roylee17]

Sorry for the false alarm, after changing the kCBMsgArgType to 1 during the initialization, things working fine now.

[raff]

ok, great!