'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2020 Christian Werner <chw at ch minus werner dot de>
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH rfcomm n 8.6 Tcl "Tcl Extension Commands"
.\" ---- man.macros begin ----
.\" The -*- nroff -*- definitions below are for supplemental macros used
.\" in Tcl/Tk manual entries.
.\"
.\" .AP type name in/out ?indent?
.\"	Start paragraph describing an argument to a library procedure.
.\"	type is type of argument (int, etc.), in/out is either "in", "out",
.\"	or "in/out" to describe whether procedure reads or modifies arg,
.\"	and indent is equivalent to second arg of .IP (shouldn't ever be
.\"	needed;  use .AS below instead)
.\"
.\" .AS ?type? ?name?
.\"	Give maximum sizes of arguments for setting tab stops.  Type and
.\"	name are examples of largest possible arguments that will be passed
.\"	to .AP later.  If args are omitted, default tab stops are used.
.\"
.\" .BS
.\"	Start box enclosure.  From here until next .BE, everything will be
.\"	enclosed in one large box.
.\"
.\" .BE
.\"	End of box enclosure.
.\"
.\" .CS
.\"	Begin code excerpt.
.\"
.\" .CE
.\"	End code excerpt.
.\"
.\" .VS ?version? ?br?
.\"	Begin vertical sidebar, for use in marking newly-changed parts
.\"	of man pages.  The first argument is ignored and used for recording
.\"	the version when the .VS was added, so that the sidebars can be
.\"	found and removed when they reach a certain age.  If another argument
.\"	is present, then a line break is forced before starting the sidebar.
.\"
.\" .VE
.\"	End of vertical sidebar.
.\"
.\" .DS
.\"	Begin an indented unfilled display.
.\"
.\" .DE
.\"	End of indented unfilled display.
.\"
.\" .SO ?manpage?
.\"	Start of list of standard options for a Tk widget. The manpage
.\"	argument defines where to look up the standard options; if
.\"	omitted, defaults to "options". The options follow on successive
.\"	lines, in three columns separated by tabs.
.\"
.\" .SE
.\"	End of list of standard options for a Tk widget.
.\"
.\" .OP cmdName dbName dbClass
.\"	Start of description of a specific option.  cmdName gives the
.\"	option's name as specified in the class command, dbName gives
.\"	the option's name in the option database, and dbClass gives
.\"	the option's class in the option database.
.\"
.\" .UL arg1 arg2
.\"	Print arg1 underlined, then print arg2 normally.
.\"
.\" .QW arg1 ?arg2?
.\"	Print arg1 in quotes, then arg2 normally (for trailing punctuation).
.\"
.\" .PQ arg1 ?arg2?
.\"	Print an open parenthesis, arg1 in quotes, then arg2 normally
.\"	(for trailing punctuation) and then a closing parenthesis.
.\"
.\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
.\"	# Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
.el \{\
.   ie !"\\$2"" .TP \\n()Cu
.   el          .TP 15
.\}
.ta \\n()Au \\n()Bu
.ie !"\\$3"" \{\
\&\\$1 \\fI\\$2\\fP (\\$3)
.\".b
.\}
.el \{\
.br
.ie !"\\$2"" \{\
\&\\$1	\\fI\\$2\\fP
.\}
.el \{\
\&\\fI\\$1\\fP
.\}
.\}
..
.\"	# define tabbing values for .AP
.de AS
.nr )A 10n
.if !"\\$1"" .nr )A \\w'\\$1'u+3n
.nr )B \\n()Au+15n
.\"
.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
.\"	# BS - start boxed text
.\"	# ^y = starting y location
.\"	# ^b = 1
.de BS
.br
.mk ^y
.nr ^b 1u
.if n .nf
.if n .ti 0
.if n \l'\\n(.lu\(ul'
.if n .fi
..
.\"	# BE - end boxed text (draw box now)
.de BE
.nf
.ti 0
.mk ^t
.ie n \l'\\n(^lu\(ul'
.el \{\
.\"	Draw four-sided box normally, but don't draw top of
.\"	box if the box started on an earlier page.
.ie !\\n(^b-1 \{\
\h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.el \}\
\h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.\}
.fi
.br
.nr ^b 0
..
.\"	# VS - start vertical sidebar
.\"	# ^Y = starting y location
.\"	# ^v = 1 (for troff;  for nroff this doesn't matter)
.de VS
.if !"\\$2"" .br
.mk ^Y
.ie n 'mc \s12\(br\s0
.el .nr ^v 1u
..
.\"	# VE - end of vertical sidebar
.de VE
.ie n 'mc
.el \{\
.ev 2
.nf
.ti 0
.mk ^t
\h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
.sp -1
.fi
.ev
.\}
.nr ^v 0
..
.\"	# Special macro to handle page bottom:  finish off current
.\"	# box/sidebar if in box/sidebar mode, then invoked standard
.\"	# page bottom macro.
.de ^B
.ev 2
'ti 0
'nf
.mk ^t
.if \\n(^b \{\
.\"	Draw three-sided box if this is the box's first page,
.\"	draw two sides but no top otherwise.
.ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.\}
.if \\n(^v \{\
.nr ^x \\n(^tu+1v-\\n(^Yu
\kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
.\}
.bp
'fi
.ev
.if \\n(^b \{\
.mk ^y
.nr ^b 2
.\}
.if \\n(^v \{\
.mk ^Y
.\}
..
.\"	# DS - begin display
.de DS
.RS
.nf
.sp
..
.\"	# DE - end display
.de DE
.fi
.RE
.sp
..
.\"	# SO - start of list of standard options
.de SO
'ie '\\$1'' .ds So \\fBoptions\\fR
'el .ds So \\fB\\$1\\fR
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
.\"	# SE - end of list of standard options
.de SE
.fi
.ft R
.LP
See the \\*(So manual entry for details on the standard options.
..
.\"	# OP - start of full description for a single option
.de OP
.LP
.nf
.ta 4c
Command-Line Name:	\\fB\\$1\\fR
Database Name:	\\fB\\$2\\fR
Database Class:	\\fB\\$3\\fR
.fi
.IP
..
.\"	# CS - begin code excerpt
.de CS
.RS
.nf
.ta .25i .5i .75i 1i
..
.\"	# CE - end code excerpt
.de CE
.fi
.RE
..
.\"	# UL - underline word
.de UL
\\$1\l'|0\(ul'\\$2
..
.\"	# QW - apply quotation marks to word
.de QW
.ie '\\*(lq'"' ``\\$1''\\$2
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\$2
..
.\"	# PQ - apply parens and quotation marks to word
.de PQ
.ie '\\*(lq'"' (``\\$1''\\$2)\\$3
.\"" fix emacs highlighting
.el (\\*(lq\\$1\\*(rq\\$2)\\$3
..
.\"	# QR - quoted range
.de QR
.ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
..
.\"	# MT - "empty" string
.de MT
.QW ""
..
.\" ---- man.macros end ----
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
\fBble\fR \- interact with Bluetooth Low Energy (BLE) devices. Requires Android 4.3 or higher.
.SH SYNOPSIS
\fBpackage require Ble\fR
.br
\fBble\fR \fIsubcommand ?options?\fR
.BE
.SH DESCRIPTION
.PP
This command is used to deal with Bluetooth Low Energy (BLE) devices. The
legal command forms with \fIsubcommands\fR (which may be abbreviated) are:
.TP
\fBble abort\fR \fIhandle\fR
.
Abort the current write transaction on the BLE connection identified by
\fIhandle\fR which was obtained earlier by a \fBble connect\fR command.
Returns an integer indicating success (1), failure (0), or system error
(less than 0).
.TP
\fBble begin\fR \fIhandle\fR
.
Starts a write transaction on the BLE connection identified by
\fIhandle\fR which was obtained earlier by a \fBble connect\fR command.
Returns an integer indicating success (1), failure (0), or system error
(less than 0).
.TP
\fBble callback\fR \fIhandle ?callback?\fR
.
If the \fIcallback\fR argument is provided that argument replaces the
callback function on the BLE connection identified by \fIhandle\fR and
returns the old callback function. Otherwise the current callback function
is returned. In contrast to e.g. the Tk event bind mechanism, the
\fIcallback\fR argument has not all the freedom of a Tcl bind script, i.e.
it must be a single command and be parseable as a list since internally the
Tcl core function \fBTcl_EvalObjv()\fR is used for executing the callback
instead of the \fBTcl_Eval*()\fR function family supporting full scripts.
.TP
\fBble characteristics\fR \fIhandle suuid sinstance\fR
.
Returns a list of characteristics of the service described by its UUID
\fIsuuid\fR and instance number \fIinstance\fR on the BLE connection
\fIhandle\fR. The list is layed out as a table with the five columns
characteristic UUID, characteristic instance number, permissions,
properties, and write type suitable for iterating using
.sp 0
.nf
\fCforeach {cuuid cinstance perm prop wrtype} \\
    [ble characteristics ...] {...}\fR
.fi
.TP
\fBble close\fR \fIhandle\fR
.
Closes the BLE connection identified by \fIhandle\fR which was obtained
earlier by a \fBble connect\fR or \fBble scanner\fR command.
.TP
\fBble connect\fR \fIaddress callback ?flag?\fR
Connects to the Bluetooth LE device with address \fIaddress\fR (expressed
as six hexadecimal 8 bit numbers separated by colons, like a Ethernet MAC
address), and arranges for the \fIcallback\fR command to be invoked on
events on the connection to this device. The optional \fIflag\fR is a
boolean with default false controlling automatic connection setup
(see the Android documentation in
\fBhttps://developer.android.com/reference/android/bluetooth/BluetoothGatt.html\fR
for more details). The callback command is called with two additional
arguments, the first is a string (\fBconnection\fR, \fBscan\fR,
\fBservice\fR, \fBcharacteristic\fR, \fBdescriptor\fR, or
\fBtransaction\fR) indicating the kind of event, the second is a
dictionary with event related information, see the section \fBEVENT DATA\fR
below. For restrictions of the \fIcallback\fR argument see the description
in \fBble callback\fR above. The result of the \fBble connect\fR command
is a handle (a string identifying the BLE connection) to be used in other
\fBble\fR subcommands. During connection establishment an automatic
discovery takes place which detects all advertised services, characteristics,
and descriptors of the remote Bluetooth LE device.
.TP
\fBble descriptors\fR \fIhandle suuid sinstance cuuid cinstance\fR
.
Returns a list of descriptors of the service and characteristic described
by its UUIDs \fIsuuid\fR and \fIcuuid\fR and instance numbers \fIsinstance\fR
and \fIcinstance\fR on the BLE connection \fIhandle\fR. The list is layed
out as a table with the two columns descriptor UUID and permissions suitable
for iterating using
.sp 0
.nf
\fCforeach {duuid perm} \\
    [ble descriptors ...] {...}\fR
.fi
.TP
\fBble disable\fR \fIhandle suuid sinstance cuuid cinstance\fR
.
Turns off notifications of a characteristic of the BLE connection
\fIhandle\fR identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID), and
\fIcinstance\fR (characteristic identifier, integer, usually 0).
.TP
\fBble disconnect\fR \fIhandle\fR
.
Initiates a disconnect of the BLE connection \fIhandle\fR if the
current connection state is disconnected. When the operation completes
the callback function of the connection is invoked.
.TP
\fBble dread\fR \fIhandle suuid sinstance cuuid cinstance duuid\fR
.
Initiates the read of a descriptor of the BLE connection \fIhandle\fR
identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID),
\fIcinstance\fR (characteristic identifier, integer, usually 0),
and \fIduuid\fR (128 bit descriptor UUID). The result is a positive
integer when the descriptor read operation is in progress, 0 or negative
on error. The completion of the descriptor read operation is indicated
through the callback function of the connection.
.TP
\fBble dwrite\fR \fIhandle suuid sinstance cuuid cinstance duuid value\fR
.
Initiates the write of a descriptor of the BLE connection \fIhandle\fR
identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID),
\fIcinstance\fR (characteristic identifier, integer, usually 0),
and \fIduuid\fR (128 bit descriptor UUID).
\fIvalue\fR is the value to be written and should be a string or byte array.
The result is a positive integer when the descriptor write operation is in
progress, 0 or negative on error. The completion of the descriptor write
operation is indicated through the callback function of the connection.
.TP
\fBble enable\fR \fIhandle suuid sinstance cuuid cinstance\fR
.
Turns on notifications of a characteristic of the BLE connection \fIhandle\fR
identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID), and
\fIcinstance\fR (characteristic identifier, integer, usually 0).
.TP
\fBble equal\fR \fIhandle uuid1 uuid2\fR
.
Tests if the given UUIDs are equal. Both can be specified in abbreviated
form and are expanded before comparison. Returns true, if the UUIDs are
the same. Unknown abbreviated or long UUIDs with respect to the connection
\fIhandle\fR compare always to false.
.TP
\fBble execute\fR \fIhandle\fR
.
Dispatches execute (commit) of the current write transaction which was
started earlier using \fBble begin\fR on the BLE connection identified
by \fIhandle\fR which was obtained earlier by a \fBble connect\fR
command. Returns an integer indicating success (1), failure (0), or
system error (less than 0). The result of the transaction is reported
in the callback with event kind \fBtransaction\fR.
.TP
\fBble expand\fR \fIhandle uuid\fR
.
Expands the given (abbreviated, short) UUID to its 128 bit (long, canonical)
form and returns a 128 bit UUID string. An error is reported if an
abbreviated or long UUID is unknown with respect to the connection
\fIhandle\fR.
.TP
\fBble getrssi\fR \fIhandle\fR
.
Requests remote SSI information from the BLE connection identified by
\fIhandle\fR which was obtained earlier by a \fBble connect\fR command.
Returns an integer indicating success (1), failure (0), or system error
(less than 0). The updated remote SSI is reported in later callbacks.
.TP
\fBble info\fR \fI?handle?\fR
.
Returns information of the BLE connection identified by \fIhandle\fR as
a dictionary made up the fields \fIhandle\fR (the connection identifier),
\fIaddress\fR (Bluetooth address), and \fIstate\fR (connection state,
one of \fBdisconnected\fR, \fBdiscovery\fR, \fBscanning\fR,
\fBconnected\fR, or \fBidle\fR. If \fIhandle\fR is omitted, a list of
all known connection identifiers is returned.
.TP
\fBble pair\fR \fIaddress\fR
.
 Initiates pairing with the Bluetooth device with address \fIaddress\fR
(expressed as six hexadecimal 8 bit numbers separated by colons, like a
Ethernet MAC address).
.TP
\fBble read\fR \fIhandle suuid sinstance cuuid cinstance\fR
.
Initiates the read of a characteristic of the BLE connection \fIhandle\fR
identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID), and
\fIcinstance\fR (characteristic identifier, integer, usually 0).
The result is a positive integer when the read operation is in progress,
0 or negative on error. The completion of the read operation is indicated
through the callback function of the connection.
.TP
\fBble reconnect\fR \fIhandle\fR
.
Initiates a reconnect of the BLE connection \fIhandle\fR if the
current connection state is disconnected. When the operation completes
the callback function of the connection is invoked with information on
the new connection state.
.TP
\fBble scanner\fR \fIcallback\fR
.
Creates a BLE connection to be used for detection (scan) of BLE devices
and returns a handle (a string identifying the BLE scanner) to be used
to deal with this scanner and arranges for the \fIcallback\fR command
to be invoked on events on the connection. See the description of
\fBble connect\fR and the section \fBEVENT DATA\fR for more details
on the \fIcallback\fR argument.
.TP
\fBble services\fR \fIhandle\fR
.
Returns a list of services of the BLE connection \fIhandle\fR. The list
is layed out as a table with the three columns service UUID, service
instance number, and service type suitable for iterating using
.sp 0
.nf
\fCforeach {suuid sinstance type} \\
    [ble services ...] {...}\fR
.fi
.TP
\fBble shorten\fR \fIhandle uuid\fR
.
Shorten the given (long, canonical) UUID to its shortest (16 or 32 bit)
form. An error is reported if the long UUID is unknown with respect to
the connection \fIhandle\fR. If no unique abbreviation is found, the
full 128 bit UUID is returned.
.TP
\fBble start\fR \fIhandle\fR
.
Starts scanning for BLE devices. Scan status and scan results are
indicated by invocations of the \fIcallback\fR function given to
the corresponding \fBble scanner\fR command.
.TP
\fBble stop\fR \fIhandle\fR
.
Stops scanning for BLE devices. Scan status is indicated by invocations
of the \fIcallback\fR function given to the corresponding \fBble scanner\fR
command.
.TP
\fBble unpair\fR \fIaddress\fR
.
Initiates release of the pairing with the Bluetooth device with address
\fIaddress\fR (expressed as six hexadecimal 8 bit numbers separated by
colons, like a Ethernet MAC address).
.TP
\fBble userdata\fR \fIhandle ?data?\fR
.
Associate or retrieve user data with the BLE connection \fIhandle\fR.
When \fIdata\fR is given it replaces the former associated user data.
When omitted, the current user data or an empty list is returned.  
.TP
\fBble write\fR \fIhandle suuid sinstance cuuid cinstance value\fR
.
Initiates the write of a characteristic of the BLE connection \fIhandle\fR
identified by \fIsuuid\fR (128 bit service UUID),
\fIsinstance\fR (service instance identifier, integer, usually 0),
\fIcuuid\fR (128 bit characteristic UUID), and
\fIcinstance\fR (characteristic identifier, integer, usually 0).
\fIvalue\fR is the value to be written and should be a string or byte array.
The result is a positive integer when the write operation is in progress,
0 or negative on error. The completion of the write operation is indicated
through the callback function of the connection.  Note: not all Android
implementations allow more than one active command (example, issuing a
\fBble read\fR immediately after a \fBble write\fR). For best compatibility,
you should wait for the callback that your write operation has completed
before issuing the next \fBble write\fR or \fBble read\fR command.
.
.SH "ABBREVIATED UUIDs"
.PP
The 128 bit UUID arguments to \fBble\fR commands can be specified
in abbreviated 16 or 32 bit form as long as the value is unique with
respect to the UUIDs learned during the discovery phase. Examples:
.sp 1
.nf
\fC
 TI SensorTag Base UUID:        F0000000-0451-4000-B000-000000000000

 IR Temperature Sensor Service: F000AA00-0451-4000-B000-000000000000
          abbreviated (32 bit): F000AA00
          abbreviated (16 bit):     AA00

 IR Temperature Sensor Value:   F000AA01-0451-4000-B000-000000000000
          abbreviated (32 bit): F000AA01
          abbreviated (16 bit):     AA01

 Generic descriptor for notify: 00002902-0000-1000-8000-00805F9B34FB
          abbreviated (32 bit): 00002902
          abbreviated (16 bit):     2902
\fR
.fi

.SH "EVENT DATA"
.PP
The first argument to callback functions is the type of event,
as described below.
.TP
\fBconnection\fR
.
Indicates change in connection state.
.TP
\fBscan\fR
.
Indicates change in scan state or reports newly detected Bluetooth LE devices.
.TP
\fBservice\fR
.
Information about a service.
.TP
\fBcharacteristic\fR
.
Information about a characteristic, used for data exchange.
.TP
\fBdescriptor\fR
.
Information about a descriptor (meta information of a characteristic).
.TP
\fBtransaction\fR
.
Indicates status of a write transaction.
.PP
The second argument to callback functions is a dictionary with keys
depending on the kind of the event. The following paragraphs list the
various event formats.
.TP
\fBhandle\fR \fIh\fR \fBstate\fR \fIs\fR
.
Connection state event for \fBble scan\fR. \fBstate\fR can be one of
\fBscanning\fR or \fBidle\fR.
.TP
\fBhandle\fR \fIh\fR \fBaddress\fR \fIa\fR \fBstate\fR \fIs\fR \fBrssi\fR \fIr\fR
.
Connection state event for \fBble connect\fR. \fBstate\fR can be one
of \fBdisconnected\fR, \fBdiscovery\fR, or \fBconnected\fR.
In the discovery phase the services, characteristics, and descriptors
of the remote device are gathered. The \fBrssi\fR field contains the
last read remote SSI (signal strength indicator) in dBm as integer number.
.TP
\fBhandle\fR \fIh\fR \fBstate\fR \fIs\fR \fBaddress\fR \fIa\fR \fBname\fR \fIn\fR \fBtype\fR \fIt\fR \fBrssi\fR \fIr\fR
.
Scan result event. \fBaddress\fR is the Bluetooth address of the remote
device, \fBname\fR it's advertised friendly name, \fBtype\fR the device
type as integer, \fBrssi\fR the receive SSI in dBm as integer.
.TP
\fBhandle\fR \fIh\fR \fBaddress\fR \fIa\fR \fBstate\fR \fIs\fR \fBrssi\fR \fIr\fR \fBsuuid\fR \fIsu\fR \fBsinstance\fR \fIsi\fR \fBtype\fR \fIt\fR
.
Service discovery event. \fBsuuid\fR is the UUID of the service,
\fBsinstance\fR the instance of that service as integer number.
Refer to \fBhttps://developer.android.com/reference/android/bluetooth/BluetoothGattService.html\fR for details.
.TP
\fBhandle\fR \fIh\fR \fBaddress\fR \fIa\fR \fBstate\fR \fIs\fR \fBrssi\fR \fIr\fR \fBsuuid\fR \fIsu\fR \fBsinstance\fR \fIsi\fR \fBcuuid\fR \fIci\fR \fBcinstance\fR \fIci\fR \fBpermissions\fR \fIp\fR \fBproperties\fR \fIq\fR \fBwritetype\fR \fIw\fR \fBaccess\fR \fIa\fR \fBvalue\fR \fIv\fR
.
Characteristic event. \fBcuuid\fR is the UUID of the characteristic,
\fBcinstance\fR the instance of that characteristic as integer number.
The items \fBpermission\fR, \fBproperties\fR, and \fBwritetype\fR are
integer numbers, too. The \fBaccess\fR item contains a one letter code
indicating the type of access (\fBc\fR for change notification,
\fBd\fR for discovery, \fBr\fR for read, \fBw\fR for write).
The \fBvalue\fR item holds the data of the characteristic as a byte array.
It's interpretation is device/characteristic depending. This event is
reported during discovery and normal operation when \fBble read\fR
or \fBble write\fR are performed locally or notifications for the
characteristic are enabled using \fBble enable\fR. Refer to
\fBhttps://developer.android.com/reference/android/bluetooth/BluetoothGattCharacteristic.html\fR for details.
.TP
\fBhandle\fR \fIh\fR \fBaddress\fR \fIa\fR \fBstate\fR \fIs\fR \fBrssi\fR \fIr\fR \fBsuuid\fR \fIsu\fR \fBsinstance\fR \fIsi\fR \fBcuuid\fR \fIci\fR \fBcinstance\fR \fIci\fR \fBduuid\fR \fIdi\fR \fBpermissions\fR \fIp\fR \fBaccess\fR \fIa\fR \fBvalue\fR \fIv\fR
.
Descriptor event. \fBduuid\fR is the UUID of the descriptor.
The item \fBpermissions\fR is an integer number, too.
The \fBaccess\fR item contains a one letter code indicating the type
of access (\fBd\fR for discovery, \fBr\fR for read, \fBw\fR for write).
The \fBvalue\fR item holds the data of the descriptor as a byte array.
It's interpretation is device/characteristic/descriptor depending.
This event is reported during discovery and normal operation when
\fBble dread\fR or \fBble dwrite\fR are performed locally. Refer to
\fBhttps://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor.html\fR for details.
.TP
\fBhandle\fR \fIh\fR \fBsuccess\fR \fIs\fR
.
Transaction result event. \fBsuccess\fR is the transaction result and is
1 for success or 0 for failure.
.SH EXAMPLE
.PP
The following example scans for Bluetooth LE devices, connects to a
TI Sensor Tag (see \fBhttp://www.ti.com/tool/cc2541dk-sensor\fR)
and enables notifications of the buttons of the device.
.sp 1
.nf
\fC
proc ble_handler {what data} {
    switch -- $what {
        scan {
            if {[dict get $data name] eq "SensorTag"} {
                # found the TI SensorTag, connect it, stop the scanner
                ble connect [dict get $data address] ble_handler 1
                ble close [dict get $data handle]
            }
        }
        connection {
            if {[dict get $data state] == "disconnected"} {
                # fall back to scanning
                ble close [dict get $data handle]
                ble start [ble scanner ble_handler]
            } elseif {[dict get $data state] == "connected"} {
                # if the TI SensorTag buttons were found,
                # it will be enabled for notifications now
                set handle [dict get $data handle]
                set cmd [ble userdata $handle]
                if {$cmd ne {}} {
                    if {[{*}$cmd]} {
                        # success, clear userdata
                        ble userdata $handle {}
                    }
                }
            }
        }
        descriptor {
            if {[string match "*2902-*" [dict get $data duuid]] &&
                [string match "*FFE1-*" [dict get $data cuuid]]} {
                # descriptor for TI SensorTag buttons found
                set flag 0
                # notification enable state, 16 bit little-endian
                #  0x0000 = disabled, 0x0001 = enabled
                binary scan [dict get $data value] s flag
                if {!$flag} {
                    # later turn on notifications of button changes
                    set handle [dict get $data handle]
                    ble userdata $handle [list ble enable $handle \\
                        [dict get $data suuid] [dict get $data sinstance] \\
                        [dict get $data cuuid] [dict get $data cinstance]]
                }
            }
        }
    }
    # dump data to stdout
    if {[dict exists $data value]} {
        # make hex string from byte array
        binary scan [dict get $data value] H* value
        dict set data value $value
    }
    puts "$what: $data"
}

ble start [ble scanner ble_handler]
\fR
.fi