Note
This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.
This is the description of the PHP API bindings for the Heart Rate Bricklet. General information and technical specifications for the Heart Rate Bricklet are summarized in its hardware description.
An installation guide for the PHP 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 24 25 26 27 28 29 | <?php
require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletHeartRate.php');
use Tinkerforge\IPConnection;
use Tinkerforge\BrickletHeartRate;
const HOST = 'localhost';
const PORT = 4223;
const UID = 'abc'; // Change to your UID
$ipcon = new IPConnection(); // Create IP connection
$c = new BrickletHeartRate(UID, $ipcon); // Create device object
$ipcon->connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Get current heart rate (in beats per minute)
$hrate = $c->getHeartRate();
echo "Heart Rate(bpm): ".$hrate."\n";
echo "\n";
echo "Press key to exit\n";
fgetc(fopen('php://stdin', 'r'));
$ipcon->disconnect();
?>
|
Download (ExampleCallback.php)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | <?php
require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletHeartRate.php');
use Tinkerforge\IPConnection;
use Tinkerforge\BrickletHeartRate;
const HOST = 'localhost';
const PORT = 4223;
const UID = 'abc'; // Change to your UID
// Callback function for heart rate (in beats per minute)
function cb_heart_rate($hrate)
{
echo "Heart Rate(bpm): " . $hrate ."\n";
echo "\n";
}
$ipcon = new IPConnection(); // Create IP connection
$hr = new BrickletHeartRate(UID, $ipcon); // Create device object
$ipcon->connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Set Period for heart rate callback to 1s (1000ms)
// Note: The callback is only called every second if the
// heart has changed since the last call!
$hr->setHeartRateCallbackPeriod(1000);
// Register heart rate callback to function cb_heart_rate
$hr->registerCallback(BrickletHeartRate::CALLBACK_HEART_RATE, 'cb_heart_rate');
echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever
?>
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Download (ExampleThreshold.php)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | <?php
require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletHeartRate.php');
use Tinkerforge\IPConnection;
use Tinkerforge\BrickletHeartRate;
const HOST = 'localhost';
const PORT = 4223;
const UID = 'abc'; // Change to your UID
// Callback for heart rate threshold reached
function cb_reached($hrate)
{
echo "Heart Rate(bpm): " . $hrate ."\n";
echo "\n";
}
$ipcon = new IPConnection(); // Create IP connection
$hr = new BrickletHeartRate(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)
$hr->setDebouncePeriod(10000);
// Register threshold reached callback to function cb_reached
$hr->registerCallback(BrickletHeartRate::CALLBACK_HEART_RATE_REACHED, 'cb_reached');
// Configure threshold for heart rate values,
// Heart Rate : greater than 70
$hr->setHeartRateCallbackThreshold('>', 50, 70);
echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever
?>
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Functions that return multiple values return them in an associative array.
Creates an object with the unique device ID $uid:
<?php $heart_rate = new BrickletHeartRate('YOUR_DEVICE_UID', $ipcon); ?>
This object can then be used after the IP Connection is connected (see examples above).
Returns the current heart rate measured.
If you want to get the heart rate periodically, it is recommended to use the callback CALLBACK_HEART_RATE and set the period with setHeartRateCallbackPeriod().
Returns the version of the API definition (major, minor, revision) 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.
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 setResponseExpected(). 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 send and errors are silently ignored, because they cannot be detected.
See setResponseExpected() for the list of function ID constants available for this function.
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 and callbacks it is always disabled.
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 send and errors are silently ignored, because they cannot be detected.
The following function ID constants are available for this function:
Changes the response expected flag for all setter and callback configuration functions of this device at once.
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' or 'd'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
The returned array has the keys uid, connected_uid, position, hardware_version, firmware_version and device_identifier.
Registers a callback with ID $id to the callable $callback. The $userData will be given as a parameter of the callback.
The available IDs with corresponding function signatures are listed below.
Sets the period in ms with which the CALLBACK_HEART_RATE callback is triggered periodically. A value of 0 turns the callback off.
CALLBACK_HEART_RATE is only triggered if the heart rate has changed since the last triggering.
The default value is 0.
Returns the period as set by setHeartRateCallbackPeriod().
Sets the thresholds for the CALLBACK_HEART_RATE_REACHED callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the heart rate is outside the min and max values |
'i' | Callback is triggered when the heart rate is inside the min and max values |
'<' | Callback is triggered when the heart rate is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the heart rate is greater than the min value (max is ignored) |
The default value is ('x', 0, 0).
The following constants are available for this function:
Returns the threshold as set by setHeartRateCallbackThreshold().
The following constants are available for this function:
The returned array has the keys option, min and max.
Sets the period in ms with which the threshold callback
is triggered, if the threshold
keeps being reached.
The default value is 100.
Returns the debounce period as set by setDebouncePeriod().
Enables the CALLBACK_BEAT_STATE_CHANGED callback.
Disables the CALLBACK_BEAT_STATE_CHANGED callback.
Returns true if the CALLBACK_BEAT_STATE_CHANGED callback is enabled.
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the registerCallback() function of the device object. The first parameter is the callback ID and the second parameter the callback function:
<?php
function myCallback($param)
{
echo $param . "\n";
}
$heart_rate->registerCallback(BrickletHeartRate::CALLBACK_EXAMPLE, 'myCallback');
?>
The available constants with corresponding function signatures 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.
<?php void callback(int $heart_rate [, mixed $userData]) ?>
This callback is triggered periodically with the period that is set by setHeartRateCallbackPeriod(). The parameter is the heart rate of the sensor.
CALLBACK_HEART_RATE is only triggered if the heart rate has changed since the last triggering.
<?php void callback(int $heart_rate [, mixed $userData]) ?>
This callback is triggered when the threshold as set by setHeartRateCallbackThreshold() is reached. The parameter is the heart rate of the sensor.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by setDebouncePeriod().
<?php void callback(int $state [, mixed $userData]) ?>
This callback provides the current heart beat state.It is called every time a heart beat is detected. The state can either be
The following constants are available for this function:
This constant is used to identify a Heart Rate Bricklet.
The getIdentity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.