This is the description of the Perl API bindings for the Temperature Bricklet. General information and technical specifications for the Temperature Bricklet are summarized in its hardware description.
An installation guide for the Perl API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | #!/usr/bin/perl
use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletTemperature;
use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Temperature Bricklet
my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $t = Tinkerforge::BrickletTemperature->new(&UID, $ipcon); # Create device object
$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected
# Get current temperature
my $temperature = $t->get_temperature();
print "Temperature: " . $temperature/100.0 . " °C\n";
print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();
|
Download (example_callback.pl)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | #!/usr/bin/perl
use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletTemperature;
use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Temperature Bricklet
# Callback subroutine for temperature callback
sub cb_temperature
{
my ($temperature) = @_;
print "Temperature: " . $temperature/100.0 . " °C\n";
}
my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $t = Tinkerforge::BrickletTemperature->new(&UID, $ipcon); # Create device object
$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected
# Register temperature callback to subroutine cb_temperature
$t->register_callback($t->CALLBACK_TEMPERATURE, 'cb_temperature');
# Set period for temperature callback to 1s (1000ms)
# Note: The temperature callback is only called every second
# if the temperature has changed since the last call!
$t->set_temperature_callback_period(1000);
print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();
|
Download (example_threshold.pl)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | #!/usr/bin/perl
use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletTemperature;
use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Temperature Bricklet
# Callback subroutine for temperature reached callback
sub cb_temperature_reached
{
my ($temperature) = @_;
print "Temperature: " . $temperature/100.0 . " °C\n";
print "It is too hot, we need air conditioning!\n";
}
my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $t = Tinkerforge::BrickletTemperature->new(&UID, $ipcon); # Create device object
$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected
# Get threshold callbacks with a debounce time of 10 seconds (10000ms)
$t->set_debounce_period(10000);
# Register temperature reached callback to subroutine cb_temperature_reached
$t->register_callback($t->CALLBACK_TEMPERATURE_REACHED, 'cb_temperature_reached');
# Configure threshold for temperature "greater than 30 °C"
$t->set_temperature_callback_threshold('>', 30*100, 0);
print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();
|
Generally, every subroutine of the Perl bindings can report an error as
Tinkerforge::Error
object via croak()
. The object has a
get_code()
and a get_message()
subroutine. There are different
error code:
All functions listed below are thread-safe.
BrickletTemperature
->
new
($uid, $ipcon)¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID $uid
:
$temperature = BrickletTemperature->new("YOUR_DEVICE_UID", $ipcon);
This object can then be used after the IP Connection is connected.
BrickletTemperature
->
get_temperature
()¶Returns: |
|
---|
Returns the temperature of the sensor.
If you want to get the temperature periodically, it is recommended
to use the CALLBACK_TEMPERATURE
callback and set the period with
set_temperature_callback_period()
.
BrickletTemperature
->
set_i2c_mode
($mode)¶Parameters: |
|
---|---|
Returns: |
|
Sets the I2C mode. Possible modes are:
If you have problems with obvious outliers in the Temperature Bricklet measurements, they may be caused by EMI issues. In this case it may be helpful to lower the I2C speed.
It is however not recommended to lower the I2C speed in applications where a high throughput needs to be achieved.
The following constants are available for this function:
For $mode:
New in version 2.0.1 (Plugin).
BrickletTemperature
->
get_i2c_mode
()¶Returns: |
|
---|
Returns the I2C mode as set by set_i2c_mode()
.
The following constants are available for this function:
For $mode:
New in version 2.0.1 (Plugin).
BrickletTemperature
->
get_identity
()¶Return Array: |
|
---|
Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
BrickletTemperature
->
register_callback
($callback_id, $function)¶Parameters: |
|
---|---|
Returns: |
|
Registers the given $function
name with the given $callback_id
.
The available callback IDs with corresponding function signatures are listed below.
BrickletTemperature
->
set_temperature_callback_period
($period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the CALLBACK_TEMPERATURE
callback is triggered
periodically. A value of 0 turns the callback off.
The CALLBACK_TEMPERATURE
callback is only triggered if the temperature has changed
since the last triggering.
BrickletTemperature
->
get_temperature_callback_period
()¶Returns: |
|
---|
Returns the period as set by set_temperature_callback_period()
.
BrickletTemperature
->
set_temperature_callback_threshold
($option, $min, $max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the CALLBACK_TEMPERATURE_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the temperature is outside the min and max values |
'i' | Callback is triggered when the temperature is inside the min and max values |
'<' | Callback is triggered when the temperature is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the temperature is greater than the min value (max is ignored) |
The following constants are available for this function:
For $option:
BrickletTemperature
->
get_temperature_callback_threshold
()¶Return Array: |
|
---|
Returns the threshold as set by set_temperature_callback_threshold()
.
The following constants are available for this function:
For $option:
BrickletTemperature
->
set_debounce_period
($debounce)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the threshold callback
is triggered, if the threshold
keeps being reached.
BrickletTemperature
->
get_debounce_period
()¶Returns: |
|
---|
Returns the debounce period as set by set_debounce_period()
.
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]";
}
$temperature->register_callback(BrickletTemperature->CALLBACK_EXAMPLE, 'my_callback')
The callback function will be called from an internal thread of the
IP Connection. In contrast to many other programming languages, variables are
not automatically shared between threads in Perl. If you want to share a global
variable between a callback function and the rest for your program it has to be
marked as :shared
. See the documentation of the threads::shared Perl module for more details.
The available constants with inherent number and type of parameters are described below.
Note
Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.
BrickletTemperature
->
CALLBACK_TEMPERATURE
¶Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
set_temperature_callback_period()
. The parameter is the
temperature of the sensor.
The CALLBACK_TEMPERATURE
callback is only triggered if the temperature has changed
since the last triggering.
BrickletTemperature
->
CALLBACK_TEMPERATURE_REACHED
¶Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
set_temperature_callback_threshold()
is reached.
The parameter is the temperature of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by set_debounce_period()
.
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.
BrickletTemperature
->
get_api_version
()¶Return Array: |
|
---|
Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
BrickletTemperature
->
get_response_expected
($function_id)¶Parameters: |
|
---|---|
Returns: |
|
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 $function_id:
BrickletTemperature
->
set_response_expected
($function_id, $response_expected)¶Parameters: |
|
---|---|
Returns: |
|
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 $function_id:
BrickletTemperature
->
set_response_expected_all
($response_expected)¶Parameters: |
|
---|---|
Returns: |
|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
BrickletTemperature
->
DEVICE_IDENTIFIER
¶This constant is used to identify a Temperature 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.
BrickletTemperature
->
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Temperature Bricklet.