Software / API Bindings / PHP / API Reference and Examples / Bricklets / Voltage/Current Bricklet 2.0

PHP - Voltage/Current Bricklet 2.0¶

This is the description of the PHP API bindings for the Voltage/Current Bricklet 2.0. General information and technical specifications for the Voltage/Current Bricklet 2.0 are summarized in its hardware description.

An installation guide for the PHP API bindings is part of their general description.

Examples¶

The example code below is Public Domain (CC0 1.0).

Simple¶

Download (ExampleSimple.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletVoltageCurrentV2.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletVoltageCurrentV2;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Voltage/Current Bricklet 2.0

$ipcon = new IPConnection(); // Create IP connection
$vc = new BrickletVoltageCurrentV2(UID, $ipcon); // Create device object

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

// Get current voltage
$voltage = $vc->getVoltage();
echo "Voltage: " . $voltage/1000.0 . " V\n";

// Get current current
$current = $vc->getCurrent();
echo "Current: " . $current/1000.0 . " A\n";

echo "Press key to exit\n";
fgetc(fopen('php://stdin', 'r'));
$ipcon->disconnect();

?>

Callback¶

Download (ExampleCallback.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletVoltageCurrentV2.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletVoltageCurrentV2;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Voltage/Current Bricklet 2.0

// Callback function for current callback
function cb_current($current)
{
    echo "Current: " . $current/1000.0 . " A\n";
}

$ipcon = new IPConnection(); // Create IP connection
$vc = new BrickletVoltageCurrentV2(UID, $ipcon); // Create device object

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

// Register current callback to function cb_current
$vc->registerCallback(BrickletVoltageCurrentV2::CALLBACK_CURRENT, 'cb_current');

// Set period for current callback to 1s (1000ms) without a threshold
$vc->setCurrentCallbackConfiguration(1000, FALSE, 'x', 0, 0);

echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever

?>

Threshold¶

Download (ExampleThreshold.php)

<?php

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletVoltageCurrentV2.php');

use Tinkerforge\IPConnection;
use Tinkerforge\BrickletVoltageCurrentV2;

const HOST = 'localhost';
const PORT = 4223;
const UID = 'XYZ'; // Change XYZ to the UID of your Voltage/Current Bricklet 2.0

// Callback function for power callback
function cb_power($power)
{
    echo "power: " . $power/1000.0 . " W\n";
}

$ipcon = new IPConnection(); // Create IP connection
$vc = new BrickletVoltageCurrentV2(UID, $ipcon); // Create device object

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

// Register power callback to function cb_power
$vc->registerCallback(BrickletVoltageCurrentV2::CALLBACK_POWER, 'cb_power');

// Configure threshold for power "greater than 10 W"
// with a debounce period of 1s (1000ms)
$vc->setPowerCallbackConfiguration(1000, FALSE, '>', 10*1000, 0);

echo "Press ctrl+c to exit\n";
$ipcon->dispatchCallbacks(-1); // Dispatch callbacks forever

?>

API¶

Functions that return multiple values return them in an associative array.

Basic Functions¶

class BrickletVoltageCurrentV2(string $uid, IPConnection $ipcon)¶

Creates an object with the unique device ID $uid:

<?php   $voltage_current_v2 = new BrickletVoltageCurrentV2('YOUR_DEVICE_UID', $ipcon);   ?>

This object can then be used after the IP Connection is connected (see examples above).

int BrickletVoltageCurrentV2::getCurrent()¶

Returns the current. The value is in mA and between -20000mA and 20000mA.

If you want to get the value periodically, it is recommended to use the CALLBACK_CURRENT callback. You can set the callback configuration with setCurrentCallbackConfiguration().

int BrickletVoltageCurrentV2::getVoltage()¶

Returns the voltage. The value is in mV and between 0mV and 36000mV.

If you want to get the value periodically, it is recommended to use the CALLBACK_VOLTAGE callback. You can set the callback configuration with setVoltageCallbackConfiguration().

int BrickletVoltageCurrentV2::getPower()¶

Returns the power. The value is in mW and between 0mV and 720000mW.

If you want to get the value periodically, it is recommended to use the CALLBACK_POWER callback. You can set the callback configuration with setPowerCallbackConfiguration().

void BrickletVoltageCurrentV2::setConfiguration(int $averaging, int $voltage_conversion_time, int $current_conversion_time)¶

Sets the configuration of the Voltage/Current Bricklet 2.0. It is possible to configure number of averages as well as voltage and current conversion time.

Averaging:

Value	Number of Averages
0	1
1	4
2	16
3	64
4	128
5	256
6	512
>=7	1024

Voltage/Current conversion:

Value	Conversion time
0	140µs
1	204µs
2	332µs
3	588µs
4	1.1ms
5	2.116ms
6	4.156ms
>=7	8.244ms

The default values are 3, 4 and 4 (64, 1.1ms, 1.1ms) for averaging, voltage conversion and current conversion.

The following constants are available for this function:

BrickletVoltageCurrentV2::AVERAGING_1 = 0
BrickletVoltageCurrentV2::AVERAGING_4 = 1
BrickletVoltageCurrentV2::AVERAGING_16 = 2
BrickletVoltageCurrentV2::AVERAGING_64 = 3
BrickletVoltageCurrentV2::AVERAGING_128 = 4
BrickletVoltageCurrentV2::AVERAGING_256 = 5
BrickletVoltageCurrentV2::AVERAGING_512 = 6
BrickletVoltageCurrentV2::AVERAGING_1024 = 7

array BrickletVoltageCurrentV2::getConfiguration()¶

Returns the configuration as set by setConfiguration().

The following constants are available for this function:

BrickletVoltageCurrentV2::AVERAGING_1 = 0
BrickletVoltageCurrentV2::AVERAGING_4 = 1
BrickletVoltageCurrentV2::AVERAGING_16 = 2
BrickletVoltageCurrentV2::AVERAGING_64 = 3
BrickletVoltageCurrentV2::AVERAGING_128 = 4
BrickletVoltageCurrentV2::AVERAGING_256 = 5
BrickletVoltageCurrentV2::AVERAGING_512 = 6
BrickletVoltageCurrentV2::AVERAGING_1024 = 7

The returned array has the keys averaging, voltage_conversion_time and current_conversion_time.

Advanced Functions¶

void BrickletVoltageCurrentV2::setCalibration(int $voltage_multiplier, int $voltage_divisor, int $current_multiplier, int $current_divisor)¶

Since the ADC and the shunt resistor used for the measurements are not perfect they need to be calibrated by a multiplier and a divisor if a very precise reading is needed.

For example, if you are expecting a current of 1000mA and you are measuring 1023mA, you can calibrate the Voltage/Current Bricklet by setting the current multiplier to 1000 and the divisor to 1023. The same applies for the voltage.

array BrickletVoltageCurrentV2::getCalibration()¶

Returns the calibration as set by setCalibration().

The returned array has the keys voltage_multiplier, voltage_divisor, current_multiplier and current_divisor.

array BrickletVoltageCurrentV2::getAPIVersion()¶: 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.

bool BrickletVoltageCurrentV2::getResponseExpected(int $function_id)¶

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.

void BrickletVoltageCurrentV2::setResponseExpected(int $function_id, bool $response_expected)¶

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.

The following function ID constants are available for this function:

BrickletVoltageCurrentV2::FUNCTION_SET_CURRENT_CALLBACK_CONFIGURATION = 2
BrickletVoltageCurrentV2::FUNCTION_SET_VOLTAGE_CALLBACK_CONFIGURATION = 6
BrickletVoltageCurrentV2::FUNCTION_SET_POWER_CALLBACK_CONFIGURATION = 10
BrickletVoltageCurrentV2::FUNCTION_SET_CONFIGURATION = 13
BrickletVoltageCurrentV2::FUNCTION_SET_CALIBRATION = 15
BrickletVoltageCurrentV2::FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
BrickletVoltageCurrentV2::FUNCTION_SET_STATUS_LED_CONFIG = 239
BrickletVoltageCurrentV2::FUNCTION_RESET = 243
BrickletVoltageCurrentV2::FUNCTION_WRITE_UID = 248

void BrickletVoltageCurrentV2::setResponseExpectedAll(bool $response_expected)¶: Changes the response expected flag for all setter and callback configuration functions of this device at once.

array BrickletVoltageCurrentV2::getSPITFPErrorCount()¶

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

ACK checksum errors,
message checksum errors,
framing errors and
overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned array has the keys error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

int BrickletVoltageCurrentV2::setBootloaderMode(int $mode)¶

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

BrickletVoltageCurrentV2::BOOTLOADER_MODE_BOOTLOADER = 0
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE = 1
BrickletVoltageCurrentV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_OK = 0
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_INVALID_MODE = 1
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_NO_CHANGE = 2
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
BrickletVoltageCurrentV2::BOOTLOADER_STATUS_CRC_MISMATCH = 5

int BrickletVoltageCurrentV2::getBootloaderMode()¶

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

BrickletVoltageCurrentV2::BOOTLOADER_MODE_BOOTLOADER = 0
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE = 1
BrickletVoltageCurrentV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
BrickletVoltageCurrentV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

void BrickletVoltageCurrentV2::setWriteFirmwarePointer(int $pointer)¶

Sets the firmware pointer for writeFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int BrickletVoltageCurrentV2::writeFirmware(array $data)¶

Writes 64 Bytes of firmware at the position as written by setWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

void BrickletVoltageCurrentV2::setStatusLEDConfig(int $config)¶

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

BrickletVoltageCurrentV2::STATUS_LED_CONFIG_OFF = 0
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_ON = 1
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_SHOW_STATUS = 3

int BrickletVoltageCurrentV2::getStatusLEDConfig()¶

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

BrickletVoltageCurrentV2::STATUS_LED_CONFIG_OFF = 0
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_ON = 1
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
BrickletVoltageCurrentV2::STATUS_LED_CONFIG_SHOW_STATUS = 3

int BrickletVoltageCurrentV2::getChipTemperature()¶

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

void BrickletVoltageCurrentV2::reset()¶

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

void BrickletVoltageCurrentV2::writeUID(int $uid)¶

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

int BrickletVoltageCurrentV2::readUID()¶: Returns the current UID as an integer. Encode as Base58 to get the usual string version.

array BrickletVoltageCurrentV2::getIdentity()¶

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.

Callback Configuration Functions¶

void BrickletVoltageCurrentV2::registerCallback(int $callback_id, callable $callback, mixed $user_data=NULL)¶

Registers the given $function with the given $callback_id. The optional $user_data will be passed as the last parameter to the function.

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

void BrickletVoltageCurrentV2::setCurrentCallbackConfiguration(int $period, bool $value_has_to_change, string $option, int $min, int $max)¶

The period in ms is the period with which the CALLBACK_CURRENT callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_CURRENT callback.

The following options are possible:

Option	Description
'x'	Threshold is turned off
'o'	Threshold is triggered when the value is outside the min and max values
'i'	Threshold is triggered when the value is inside or equal to the min and max values
'<'	Threshold is triggered when the value is smaller than the min value (max is ignored)
'>'	Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

array BrickletVoltageCurrentV2::getCurrentCallbackConfiguration()¶

Returns the callback configuration as set by setCurrentCallbackConfiguration().

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

The returned array has the keys period, value_has_to_change, option, min and max.

void BrickletVoltageCurrentV2::setVoltageCallbackConfiguration(int $period, bool $value_has_to_change, string $option, int $min, int $max)¶

The period in ms is the period with which the CALLBACK_VOLTAGE callback is triggered periodically. A value of 0 turns the callback off.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_VOLTAGE callback.

The following options are possible:

Option	Description
'x'	Threshold is turned off
'o'	Threshold is triggered when the value is outside the min and max values
'i'	Threshold is triggered when the value is inside or equal to the min and max values
'<'	Threshold is triggered when the value is smaller than the min value (max is ignored)
'>'	Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

array BrickletVoltageCurrentV2::getVoltageCallbackConfiguration()¶

Returns the callback configuration as set by setVoltageCallbackConfiguration().

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

The returned array has the keys period, value_has_to_change, option, min and max.

void BrickletVoltageCurrentV2::setPowerCallbackConfiguration(int $period, bool $value_has_to_change, string $option, int $min, int $max)¶

The period in ms is the period with which the CALLBACK_POWER callback is triggered periodically. A value of 0 turns the callback off.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_POWER callback.

The following options are possible:

Option	Description
'x'	Threshold is turned off
'o'	Threshold is triggered when the value is outside the min and max values
'i'	Threshold is triggered when the value is inside or equal to the min and max values
'<'	Threshold is triggered when the value is smaller than the min value (max is ignored)
'>'	Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

array BrickletVoltageCurrentV2::getPowerCallbackConfiguration()¶

Returns the callback configuration as set by setPowerCallbackConfiguration().

The following constants are available for this function:

BrickletVoltageCurrentV2::THRESHOLD_OPTION_OFF = 'x'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_OUTSIDE = 'o'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_INSIDE = 'i'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_SMALLER = '<'
BrickletVoltageCurrentV2::THRESHOLD_OPTION_GREATER = '>'

The returned array has the keys period, value_has_to_change, option, min and max.

Callbacks¶

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";
}

$voltage_current_v2->registerCallback(BrickletVoltageCurrentV2::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.

int BrickletVoltageCurrentV2::CALLBACK_CURRENT¶

<?php   void callback(int $current [, mixed $user_data])   ?>

This callback is triggered periodically according to the configuration set by setCurrentCallbackConfiguration().

The parameter is the same as getCurrent().

int BrickletVoltageCurrentV2::CALLBACK_VOLTAGE¶

<?php   void callback(int $voltage [, mixed $user_data])   ?>

This callback is triggered periodically according to the configuration set by setVoltageCallbackConfiguration().

The parameter is the same as getVoltage().

int BrickletVoltageCurrentV2::CALLBACK_POWER¶

<?php   void callback(int $power [, mixed $user_data])   ?>

This callback is triggered periodically according to the configuration set by setPowerCallbackConfiguration().

The parameter is the same as getPower().

Constants¶

int BrickletVoltageCurrentV2::DEVICE_IDENTIFIER¶

This constant is used to identify a Voltage/Current Bricklet 2.0.

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.

string BrickletVoltageCurrentV2::DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Voltage/Current Bricklet 2.0.