This is the description of the Python API bindings for the Voltage/Current Bricklet. General information and technical specifications for the Voltage/Current Bricklet are summarized in its hardware description.
An installation guide for the Python 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 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Voltage/Current Bricklet
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current import BrickletVoltageCurrent
if __name__ == "__main__":
ipcon = IPConnection() # Create IP connection
vc = BrickletVoltageCurrent(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.get_voltage()
print("Voltage: " + str(voltage/1000.0) + " V")
# Get current current
current = vc.get_current()
print("Current: " + str(current/1000.0) + " A")
input("Press key to exit\n") # Use raw_input() in Python 2
ipcon.disconnect()
|
Download (example_callback.py)
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 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Voltage/Current Bricklet
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current import BrickletVoltageCurrent
# Callback function for current callback
def cb_current(current):
print("Current: " + str(current/1000.0) + " A")
if __name__ == "__main__":
ipcon = IPConnection() # Create IP connection
vc = BrickletVoltageCurrent(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.register_callback(vc.CALLBACK_CURRENT, cb_current)
# Set period for current callback to 1s (1000ms)
# Note: The current callback is only called every second
# if the current has changed since the last call!
vc.set_current_callback_period(1000)
input("Press key to exit\n") # Use raw_input() in Python 2
ipcon.disconnect()
|
Download (example_threshold.py)
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 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Voltage/Current Bricklet
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current import BrickletVoltageCurrent
# Callback function for power reached callback
def cb_power_reached(power):
print("Power: " + str(power/1000.0) + " W")
if __name__ == "__main__":
ipcon = IPConnection() # Create IP connection
vc = BrickletVoltageCurrent(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)
vc.set_debounce_period(10000)
# Register power reached callback to function cb_power_reached
vc.register_callback(vc.CALLBACK_POWER_REACHED, cb_power_reached)
# Configure threshold for power "greater than 10 W"
vc.set_power_callback_threshold(">", 10*1000, 0)
input("Press key to exit\n") # Use raw_input() in Python 2
ipcon.disconnect()
|
Generally, every function of the Python bindings can throw an
tinkerforge.ip_connection.Error
exception that has a value
and a
description
property. value
can have different values:
All functions listed below are thread-safe.
BrickletVoltageCurrent
(uid, ipcon)¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID uid
:
voltage_current = BrickletVoltageCurrent("YOUR_DEVICE_UID", ipcon)
This object can then be used after the IP Connection is connected.
BrickletVoltageCurrent.
get_current
()¶Returns: |
|
---|
Returns the current.
If you want to get the current periodically, it is recommended to use the
CALLBACK_CURRENT
callback and set the period with
set_current_callback_period()
.
BrickletVoltageCurrent.
get_voltage
()¶Returns: |
|
---|
Returns the voltage.
If you want to get the voltage periodically, it is recommended to use the
CALLBACK_VOLTAGE
callback and set the period with
set_voltage_callback_period()
.
BrickletVoltageCurrent.
get_power
()¶Returns: |
|
---|
Returns the power.
If you want to get the power periodically, it is recommended to use the
CALLBACK_POWER
callback and set the period with
set_power_callback_period()
.
BrickletVoltageCurrent.
set_configuration
(averaging, voltage_conversion_time, current_conversion_time)¶Parameters: |
|
---|---|
Returns: |
|
Sets the configuration of the Voltage/Current Bricklet. It is possible to configure number of averages as well as voltage and current conversion time.
The following constants are available for this function:
For averaging:
For voltage_conversion_time:
For current_conversion_time:
BrickletVoltageCurrent.
get_configuration
()¶Return Object: |
|
---|
Returns the configuration as set by set_configuration()
.
The following constants are available for this function:
For averaging:
For voltage_conversion_time:
For current_conversion_time:
BrickletVoltageCurrent.
set_calibration
(gain_multiplier, gain_divisor)¶Parameters: |
|
---|---|
Returns: |
|
Since the shunt resistor that is used to measure the current is not perfectly precise, it needs to be calibrated by a multiplier and divisor if a very precise reading is needed.
For example, if you are expecting a measurement of 1000mA and you are measuring 1023mA, you can calibrate the Voltage/Current Bricklet by setting the multiplier to 1000 and the divisor to 1023.
BrickletVoltageCurrent.
get_calibration
()¶Return Object: |
|
---|
Returns the calibration as set by set_calibration()
.
BrickletVoltageCurrent.
get_identity
()¶Return Object: |
|
---|
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.
BrickletVoltageCurrent.
register_callback
(callback_id, function)¶Parameters: |
|
---|---|
Returns: |
|
Registers the given function
with the given callback_id
.
The available callback IDs with corresponding function signatures are listed below.
BrickletVoltageCurrent.
set_current_callback_period
(period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the CALLBACK_CURRENT
callback is triggered
periodically. A value of 0 turns the callback off.
The CALLBACK_CURRENT
callback is only triggered if the current has changed since
the last triggering.
BrickletVoltageCurrent.
get_current_callback_period
()¶Returns: |
|
---|
Returns the period as set by set_current_callback_period()
.
BrickletVoltageCurrent.
set_voltage_callback_period
(period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the CALLBACK_VOLTAGE
callback is triggered
periodically. A value of 0 turns the callback off.
The CALLBACK_VOLTAGE
callback is only triggered if the voltage has changed since
the last triggering.
BrickletVoltageCurrent.
get_voltage_callback_period
()¶Returns: |
|
---|
Returns the period as set by set_voltage_callback_period()
.
BrickletVoltageCurrent.
set_power_callback_period
(period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the CALLBACK_POWER
callback is triggered
periodically. A value of 0 turns the callback off.
The CALLBACK_POWER
callback is only triggered if the power has changed since the
last triggering.
BrickletVoltageCurrent.
get_power_callback_period
()¶Returns: |
|
---|
Returns the period as set by get_power_callback_period()
.
BrickletVoltageCurrent.
set_current_callback_threshold
(option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the CALLBACK_CURRENT_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the current is outside the min and max values |
'i' | Callback is triggered when the current is inside the min and max values |
'<' | Callback is triggered when the current is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the current is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
get_current_callback_threshold
()¶Return Object: |
|
---|
Returns the threshold as set by set_current_callback_threshold()
.
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
set_voltage_callback_threshold
(option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the CALLBACK_VOLTAGE_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the voltage is outside the min and max values |
'i' | Callback is triggered when the voltage is inside the min and max values |
'<' | Callback is triggered when the voltage is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the voltage is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
get_voltage_callback_threshold
()¶Return Object: |
|
---|
Returns the threshold as set by set_voltage_callback_threshold()
.
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
set_power_callback_threshold
(option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the CALLBACK_POWER_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the power is outside the min and max values |
'i' | Callback is triggered when the power is inside the min and max values |
'<' | Callback is triggered when the power is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the power is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
get_power_callback_threshold
()¶Return Object: |
|
---|
Returns the threshold as set by set_power_callback_threshold()
.
The following constants are available for this function:
For option:
BrickletVoltageCurrent.
set_debounce_period
(debounce)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the threshold callbacks
are triggered, if the thresholds
keep being reached.
BrickletVoltageCurrent.
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:
def my_callback(param):
print(param)
voltage_current.register_callback(BrickletVoltageCurrent.CALLBACK_EXAMPLE, my_callback)
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.
BrickletVoltageCurrent.
CALLBACK_CURRENT
¶Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
set_current_callback_period()
. The parameter is the current of the
sensor.
The CALLBACK_CURRENT
callback is only triggered if the current has changed since
the last triggering.
BrickletVoltageCurrent.
CALLBACK_VOLTAGE
¶Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
set_voltage_callback_period()
. The parameter is the voltage of
the sensor.
The CALLBACK_VOLTAGE
callback is only triggered if the voltage has changed since
the last triggering.
BrickletVoltageCurrent.
CALLBACK_POWER
¶Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
set_power_callback_period()
. The parameter is the power of the
sensor.
The CALLBACK_POWER
callback is only triggered if the power has changed since the
last triggering.
BrickletVoltageCurrent.
CALLBACK_CURRENT_REACHED
¶Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
set_current_callback_threshold()
is reached.
The parameter is the current of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by set_debounce_period()
.
BrickletVoltageCurrent.
CALLBACK_VOLTAGE_REACHED
¶Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
set_voltage_callback_threshold()
is reached.
The parameter is the voltage of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by set_debounce_period()
.
BrickletVoltageCurrent.
CALLBACK_POWER_REACHED
¶Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
set_power_callback_threshold()
is reached.
The parameter is the power 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.
BrickletVoltageCurrent.
get_api_version
()¶Return Object: |
|
---|
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.
BrickletVoltageCurrent.
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:
BrickletVoltageCurrent.
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:
BrickletVoltageCurrent.
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.
BrickletVoltageCurrent.
DEVICE_IDENTIFIER
¶This constant is used to identify a Voltage/Current 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.
BrickletVoltageCurrent.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Voltage/Current Bricklet.