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This function will wait until a Bluetooth event is raised. It has an optional timeout.
An event is a notification that something has happened on the Bluetooth interface.
The events are queued until btEventDone has been called.
For some events, an appropriate action should be done before calling btEventDone, as described in the table:
Event#
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Event
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Action needed
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Action
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1
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An incoming connection has been received.
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Yes
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Call btHandleSerialPortIncomingConnection to handle the serial port.
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2
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A pairing request have been received.
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Yes
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Call btHandlePairingRequest to find more information about the request and call btSendPairResponse to send the response.
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3
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A new device has been found.
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No
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Call btDeviceInfo to find more information about the device.
Note that this event is not generated for known devices, e.g. paired or connected devices, or devices that have been found previously.
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4
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A known device has been lost.
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No
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None.
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16
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A BLE notification has been received.
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Yes
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Call btleHandleNotification to get the value from the notification.
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btWaitEvent notifies the application of the oldest queued event.
This means that until btEventDone is called, btWaitEvent will continue to report the same event.
Note: waiting for an event using this function will block the calling thread.
Input:
timeout : INT (-1,0..32767) (default -1)
Timeout period in milliseconds to wait.
0
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-
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Disable timeout. The function will return immediately.
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-1
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-
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Wait forever. The function will only return when data is received.
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Output:
dev : STRING
The address of the device the event is related to.
Returns: INT
16
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-
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_BT_EVENT_NOTIFY
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A BLE notification has been received.
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4
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-
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_BT_EVENT_DEV_LOST
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A known device has been lost.
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3
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-
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_BT_EVENT_DEV_FOUND
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A new device has found.
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2
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-
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_BT_EVENT_PAIR_REQ
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A pairing request have been received.
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1
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-
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_BT_EVENT_INCOMING
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An incoming connection has been received.
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0
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-
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_BT_ERR_NOT_SUPPORTED
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The API is not supported.
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-1
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-
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_BT_ERR_NOT_OPEN
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The adapter is not powered(see btPower).
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-5
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-
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_BT_ERR_NO_ADAP
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Could not find adapter.
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-8
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-
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_BT_ERR_INVAL
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Invalid argument.
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-9
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-
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_BT_ERR_NODATA
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No valid data found.
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-17
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-
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_BT_ERR_TIMEOUT
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Timeout
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Declaration:
FUNCTION btWaitEvent : INT;
VAR_INPUT
timeout : INT := -1;
dev : ACCESS STRING;
END_VAR;
Example:
...
THREAD_BLOCK btThread
VAR
rc : INT;
address : STRING;
ch : SINT;
pass : DINT;
END_VAR;
WHILE TRUE DO
rc := btWaitEvent(timeout:=10000, dev := address);
IF rc <> _BT_ERR_TIMEOUT THEN
DebugFmt(message:="event \1: "+address, v1:=rc);
CASE rc OF
_BT_EVENT_INCOMING:
rc := btHandleSerialPortIncomingConnection(ch := ch, port := port);
DebugFmt(message:="btHandleSerialPortIncomingConnection(\2) : \1, \3", v1:=rc, v2:=ch, v3:=port);
_BT_EVENT_DEV_FOUND:
DebugFmt(message:="Found "+address);
_BT_EVENT_DEV_LOST:
DebugFmt(message:="Lost "+address);
_BT_EVENT_PAIR_REQ:
DebugFmt(message:="Requested confirm for "+address);
rc := btHandlePairRequest(passkey:=pass);
DebugFmt(message:="Pass: \4, \1", v1:=rc, v4:=pass);
rc := guiShowMessage(message:="Is the pairing code "+dintToStr(v:=pass)+" correct?", type := 2, timeout := 20);
DebugFmt(message:="guiShowMessage: \1", v1:=rc);
rc := btSendPairResponse(accept:=(rc = 3));
DebugFmt(message:="btSendPairResponse: \1", v1:=rc);
ELSE
DebugFmt(message:="unknown event: \1", v1:=rc);
END_CASE;
btEventDone();
END_IF;
END_WHILE;
END_THREAD_BLOCK;
...
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