Perl - RS232 Bricklet¶

Loopback¶

Download (example_loopback.pl)

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#!/usr/bin/perl

# For this example connect the RX1 and TX pin to receive the send message

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletRS232;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your RS232 Bricklet

# Convert string to char array with length 60, as needed by write
sub string_to_char_array
{
    my ($message) = @_;

    my @chars = split('', $message);
    my @array = ("\0") x 60;

    for my $i (0..(scalar(@chars) - 1)) {
        $array[$i] = $chars[$i];
    }

    return \@array;
}

# Assume that the message consists of ASCII characters and
# convert it from an array of chars to a string
sub char_array_to_string
{
    my ($message, $length) = @_;

    return substr(join('', @{$message}), 0, $length);
}

# Callback subroutine for read callback
sub cb_read
{
    my ($message, $length) = @_;

    my $str = char_array_to_string($message, $length);
    print "Message (Length: " . $length . "): \"" . $str . "\"\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $rs232 = Tinkerforge::BrickletRS232->new(&UID, $ipcon); # Create device object

$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected

# Register read callback to subroutine cb_read
$rs232->register_callback($rs232->CALLBACK_READ, 'cb_read');

# Enable read callback
$rs232->enable_read_callback();

# Write "test" string
my $message = string_to_char_array('test');
$rs232->write($message, 4);

print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();

Basic Functions¶

BrickletRS232->new($uid, $ipcon)¶

Parameters:	$uid – Type: string $ipcon – Type: IPConnection
Returns:	$rs232 – Type: BrickletRS232

Creates an object with the unique device ID $uid:

$rs232 = BrickletRS232->new("YOUR_DEVICE_UID", $ipcon);

This object can then be used after the IP Connection is connected.

BrickletRS232->write(\@message, $length)¶

Parameters:	\@message – Type: [char, ...], Length: 60 $length – Type: int, Range: [0 to 60]
Returns:	$written – Type: int, Range: [0 to 60]

Writes a string of up to 60 characters to the RS232 interface. The string can be binary data, ASCII or similar is not necessary.

The length of the string has to be given as an additional parameter.

The return value is the number of bytes that could be written.

See set_configuration() for configuration possibilities regarding baudrate, parity and so on.

BrickletRS232->read()¶

Return Array:	0: \@message – Type: [char, ...], Length: 60 1: $length – Type: int, Range: [0 to 60]

Returns the currently buffered message. The maximum length of message is 60. If the returned length is 0, no new data was available.

Instead of polling with this function, you can also use callbacks. See enable_read_callback() and CALLBACK_READ callback.

BrickletRS232->set_configuration($baudrate, $parity, $stopbits, $wordlength, $hardware_flowcontrol, $software_flowcontrol)¶

Parameters:	$baudrate – Type: int, Range: See constants, Default: 11 $parity – Type: int, Range: See constants, Default: 0 $stopbits – Type: int, Range: See constants, Default: 1 $wordlength – Type: int, Range: See constants, Default: 8 $hardware_flowcontrol – Type: int, Range: See constants, Default: 0 $software_flowcontrol – Type: int, Range: See constants, Default: 0
Returns:	undef

Sets the configuration for the RS232 communication.

Hard-/Software flow control can either be on or off but not both simultaneously on.

The following constants are available for this function:

For $baudrate:

• BrickletRS232->BAUDRATE_300 = 0
• BrickletRS232->BAUDRATE_600 = 1
• BrickletRS232->BAUDRATE_1200 = 2
• BrickletRS232->BAUDRATE_2400 = 3
• BrickletRS232->BAUDRATE_4800 = 4
• BrickletRS232->BAUDRATE_9600 = 5
• BrickletRS232->BAUDRATE_14400 = 6
• BrickletRS232->BAUDRATE_19200 = 7
• BrickletRS232->BAUDRATE_28800 = 8
• BrickletRS232->BAUDRATE_38400 = 9
• BrickletRS232->BAUDRATE_57600 = 10
• BrickletRS232->BAUDRATE_115200 = 11
• BrickletRS232->BAUDRATE_230400 = 12

For $parity:

• BrickletRS232->PARITY_NONE = 0
• BrickletRS232->PARITY_ODD = 1
• BrickletRS232->PARITY_EVEN = 2
• BrickletRS232->PARITY_FORCED_PARITY_1 = 3
• BrickletRS232->PARITY_FORCED_PARITY_0 = 4

For $stopbits:

• BrickletRS232->STOPBITS_1 = 1
• BrickletRS232->STOPBITS_2 = 2

For $wordlength:

• BrickletRS232->WORDLENGTH_5 = 5
• BrickletRS232->WORDLENGTH_6 = 6
• BrickletRS232->WORDLENGTH_7 = 7
• BrickletRS232->WORDLENGTH_8 = 8

For $hardware_flowcontrol:

• BrickletRS232->HARDWARE_FLOWCONTROL_OFF = 0
• BrickletRS232->HARDWARE_FLOWCONTROL_ON = 1

For $software_flowcontrol:

• BrickletRS232->SOFTWARE_FLOWCONTROL_OFF = 0
• BrickletRS232->SOFTWARE_FLOWCONTROL_ON = 1

BrickletRS232->get_configuration()¶

Return Array:	0: $baudrate – Type: int, Range: See constants, Default: 11 1: $parity – Type: int, Range: See constants, Default: 0 2: $stopbits – Type: int, Range: See constants, Default: 1 3: $wordlength – Type: int, Range: See constants, Default: 8 4: $hardware_flowcontrol – Type: int, Range: See constants, Default: 0 5: $software_flowcontrol – Type: int, Range: See constants, Default: 0

Returns the configuration as set by set_configuration().

The following constants are available for this function:

For $baudrate:

• BrickletRS232->BAUDRATE_300 = 0
• BrickletRS232->BAUDRATE_600 = 1
• BrickletRS232->BAUDRATE_1200 = 2
• BrickletRS232->BAUDRATE_2400 = 3
• BrickletRS232->BAUDRATE_4800 = 4
• BrickletRS232->BAUDRATE_9600 = 5
• BrickletRS232->BAUDRATE_14400 = 6
• BrickletRS232->BAUDRATE_19200 = 7
• BrickletRS232->BAUDRATE_28800 = 8
• BrickletRS232->BAUDRATE_38400 = 9
• BrickletRS232->BAUDRATE_57600 = 10
• BrickletRS232->BAUDRATE_115200 = 11
• BrickletRS232->BAUDRATE_230400 = 12

For $parity:

• BrickletRS232->PARITY_NONE = 0
• BrickletRS232->PARITY_ODD = 1
• BrickletRS232->PARITY_EVEN = 2
• BrickletRS232->PARITY_FORCED_PARITY_1 = 3
• BrickletRS232->PARITY_FORCED_PARITY_0 = 4

For $stopbits:

• BrickletRS232->STOPBITS_1 = 1
• BrickletRS232->STOPBITS_2 = 2

For $wordlength:

• BrickletRS232->WORDLENGTH_5 = 5
• BrickletRS232->WORDLENGTH_6 = 6
• BrickletRS232->WORDLENGTH_7 = 7
• BrickletRS232->WORDLENGTH_8 = 8

For $hardware_flowcontrol:

• BrickletRS232->HARDWARE_FLOWCONTROL_OFF = 0
• BrickletRS232->HARDWARE_FLOWCONTROL_ON = 1

For $software_flowcontrol:

• BrickletRS232->SOFTWARE_FLOWCONTROL_OFF = 0
• BrickletRS232->SOFTWARE_FLOWCONTROL_ON = 1

BrickletRS232->set_break_condition($break_time)¶

Parameters:	$break_time – Type: int, Unit: 1 ms, Range: [0 to 216 - 1]
Returns:	undef

Sets a break condition (the TX output is forced to a logic 0 state). The parameter sets the hold-time of the break condition.

New in version 2.0.2 (Plugin).

BrickletRS232->read_frame()¶

Return Array:	0: \@message – Type: [char, ...], Length: 60 1: $length – Type: int, Range: [0 to 60]

Returns up to one frame of bytes from the read buffer. The frame size is configured with set_frame_readable_callback_configuration(). If the returned length is 0, no new data was available.

New in version 2.0.4 (Plugin).

Advanced Functions¶

BrickletRS232->get_identity()¶

Return Array:

0: $uid – Type: string, Length: up to 8 1: $connected_uid – Type: string, Length: up to 8 2: $position – Type: char, Range: ['a' to 'h', 'z'] 3: \@hardware_version – Type: [int, ...], Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255] 4: \@firmware_version – Type: [int, ...], Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255] 5: $device_identifier – Type: int, Range: [0 to 216 - 1]

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

BrickletRS232->register_callback($callback_id, $function)¶

Parameters:	$callback_id – Type: int $function – Type: string
Returns:	undef

Registers the given $function name with the given $callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletRS232->enable_read_callback()¶

Returns:	undef

Enables the CALLBACK_READ callback. This will disable the CALLBACK_FRAME_READABLE callback.

By default the callback is disabled.

BrickletRS232->disable_read_callback()¶

Returns:	undef

Disables the CALLBACK_READ callback.

By default the callback is disabled.

BrickletRS232->is_read_callback_enabled()¶

Returns:	$enabled – Type: bool, Default: 0

Returns true if the CALLBACK_READ callback is enabled, false otherwise.

BrickletRS232->set_frame_readable_callback_configuration($frame_size)¶

Parameters:	$frame_size – Type: int, Unit: 1 B, Range: [0 to 100], Default: 0
Returns:	undef

Configures the CALLBACK_FRAME_READABLE callback. The frame size is the number of bytes, that have to be readable to trigger the callback. A frame size of 0 disables the callback. A frame size greater than 0 enables the callback and disables the CALLBACK_READ callback.

By default the callback is disabled.

New in version 2.0.4 (Plugin).

BrickletRS232->get_frame_readable_callback_configuration()¶

Returns:	$frame_size – Type: int, Unit: 1 B, Range: [0 to 100], Default: 0

Returns the callback configuration as set by set_frame_readable_callback_configuration().

New in version 2.0.4 (Plugin).

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function name:

sub my_callback
{
    print "@_[0]";
}

$rs232->register_callback(BrickletRS232->CALLBACK_EXAMPLE, 'my_callback')

The callback function will be called from an internal thread of the IP Connection. In contrast to many other programming languages, variables are not automatically shared between threads in Perl. If you want to share a global variable between a callback function and the rest for your program it has to be marked as :shared. See the documentation of the threads::shared Perl module for more details.

The available constants with inherent number and type of parameters are described below.

BrickletRS232->CALLBACK_READ¶

Callback Parameters:	\@message – Type: [char, ...], Length: 60 $length – Type: int, Range: [1 to 60]

This callback is called if new data is available. The message has a maximum size of 60 characters. The actual length of the message is given in addition.

To enable this callback, use enable_read_callback().

BrickletRS232->CALLBACK_ERROR¶

Callback Parameters:	$error – Type: int, Range: See constants

This callback is called if an error occurs. Possible errors are overrun, parity or framing error.

The following constants are available for this function:

For $error:

• BrickletRS232->ERROR_OVERRUN = 1
• BrickletRS232->ERROR_PARITY = 2
• BrickletRS232->ERROR_FRAMING = 4

New in version 2.0.1 (Plugin).

BrickletRS232->CALLBACK_FRAME_READABLE¶

Callback Parameters:	$frame_count – Type: int, Range: [0 to 255]

This callback is called if at least one frame of data is readable. The frame size is configured with set_frame_readable_callback_configuration(). The frame count parameter is the number of frames that can be read. This callback is triggered only once until read() or read_frame() is called. This means, that if you have configured a frame size of X bytes, you can read exactly X bytes using the read_frame() function, every time the callback triggers without checking the frame count parameter.

New in version 2.0.4 (Plugin).

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

BrickletRS232->get_api_version()¶

Return Array:	0: \@api_version – Type: [int, ...], Length: 3 0: $major – Type: int, Range: [0 to 255] 1: $minor – Type: int, Range: [0 to 255] 2: $revision – Type: int, Range: [0 to 255]

Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletRS232->get_response_expected($function_id)¶

Parameters:	$function_id – Type: int, Range: See constants
Returns:	$response_expected – Type: bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For $function_id:

• BrickletRS232->FUNCTION_ENABLE_READ_CALLBACK = 3
• BrickletRS232->FUNCTION_DISABLE_READ_CALLBACK = 4
• BrickletRS232->FUNCTION_SET_CONFIGURATION = 6
• BrickletRS232->FUNCTION_SET_BREAK_CONDITION = 10
• BrickletRS232->FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 11

BrickletRS232->set_response_expected($function_id, $response_expected)¶

Parameters:	$function_id – Type: int, Range: See constants $response_expected – Type: bool
Returns:	undef

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For $function_id:

• BrickletRS232->FUNCTION_ENABLE_READ_CALLBACK = 3
• BrickletRS232->FUNCTION_DISABLE_READ_CALLBACK = 4
• BrickletRS232->FUNCTION_SET_CONFIGURATION = 6
• BrickletRS232->FUNCTION_SET_BREAK_CONDITION = 10
• BrickletRS232->FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 11

BrickletRS232->set_response_expected_all($response_expected)¶

Parameters:	$response_expected – Type: bool
Returns:	undef

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Constants¶

BrickletRS232->DEVICE_IDENTIFIER¶

This constant is used to identify a RS232 Bricklet.

The get_identity() function and the IPConnection->CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletRS232->DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a RS232 Bricklet.