This is the description of the Python 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 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 2.0
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current_v2 import BrickletVoltageCurrentV2
if __name__ == "__main__":
ipcon = IPConnection() # Create IP connection
vc = 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.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 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Voltage/Current Bricklet 2.0
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current_v2 import BrickletVoltageCurrentV2
# 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 = 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.register_callback(vc.CALLBACK_CURRENT, cb_current)
# Set period for current callback to 1s (1000ms) without a threshold
vc.set_current_callback_configuration(1000, False, "x", 0, 0)
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 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Voltage/Current Bricklet 2.0
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_voltage_current_v2 import BrickletVoltageCurrentV2
# Callback function for power callback
def cb_power(power):
print("power: " + str(power/1000.0) + " W")
if __name__ == "__main__":
ipcon = IPConnection() # Create IP connection
vc = 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.register_callback(vc.CALLBACK_POWER, cb_power)
# Configure threshold for power "greater than 10 W"
# with a debounce period of 1s (1000ms)
vc.set_power_callback_configuration(1000, False, ">", 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.
BrickletVoltageCurrentV2
(uid, ipcon)¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID uid
:
voltage_current_v2 = BrickletVoltageCurrentV2("YOUR_DEVICE_UID", ipcon)
This object can then be used after the IP Connection is connected.
BrickletVoltageCurrentV2.
get_current
()¶Returns: |
|
---|
Returns the current.
If you want to get the value periodically, it is recommended to use the
CALLBACK_CURRENT
callback. You can set the callback configuration
with set_current_callback_configuration()
.
BrickletVoltageCurrentV2.
get_voltage
()¶Returns: |
|
---|
Returns the voltage.
If you want to get the value periodically, it is recommended to use the
CALLBACK_VOLTAGE
callback. You can set the callback configuration
with set_voltage_callback_configuration()
.
BrickletVoltageCurrentV2.
get_power
()¶Returns: |
|
---|
Returns the power.
If you want to get the value periodically, it is recommended to use the
CALLBACK_POWER
callback. You can set the callback configuration
with set_power_callback_configuration()
.
BrickletVoltageCurrentV2.
set_configuration
(averaging, voltage_conversion_time, current_conversion_time)¶Parameters: |
|
---|---|
Returns: |
|
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.
The following constants are available for this function:
For averaging:
For voltage_conversion_time:
For current_conversion_time:
BrickletVoltageCurrentV2.
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:
BrickletVoltageCurrentV2.
set_calibration
(voltage_multiplier, voltage_divisor, current_multiplier, current_divisor)¶Parameters: |
|
---|---|
Returns: |
|
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.
The calibration will be saved on the EEPROM of the Voltage/Current Bricklet and only needs to be done once.
BrickletVoltageCurrentV2.
get_calibration
()¶Return Object: |
|
---|
Returns the calibration as set by set_calibration()
.
BrickletVoltageCurrentV2.
get_spitfp_error_count
()¶Return Object: |
|
---|
Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
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.
BrickletVoltageCurrentV2.
set_status_led_config
(config)¶Parameters: |
|
---|---|
Returns: |
|
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:
For config:
BrickletVoltageCurrentV2.
get_status_led_config
()¶Returns: |
|
---|
Returns the configuration as set by set_status_led_config()
The following constants are available for this function:
For config:
BrickletVoltageCurrentV2.
get_chip_temperature
()¶Returns: |
|
---|
Returns the temperature 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.
BrickletVoltageCurrentV2.
reset
()¶Returns: |
|
---|
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!
BrickletVoltageCurrentV2.
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.
BrickletVoltageCurrentV2.
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.
BrickletVoltageCurrentV2.
set_current_callback_configuration
(period, value_has_to_change, option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
The period 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 following constants are available for this function:
For option:
BrickletVoltageCurrentV2.
get_current_callback_configuration
()¶Return Object: |
|
---|
Returns the callback configuration as set by set_current_callback_configuration()
.
The following constants are available for this function:
For option:
BrickletVoltageCurrentV2.
set_voltage_callback_configuration
(period, value_has_to_change, option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
The period is the period with which the CALLBACK_VOLTAGE
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_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 following constants are available for this function:
For option:
BrickletVoltageCurrentV2.
get_voltage_callback_configuration
()¶Return Object: |
|
---|
Returns the callback configuration as set by set_voltage_callback_configuration()
.
The following constants are available for this function:
For option:
BrickletVoltageCurrentV2.
set_power_callback_configuration
(period, value_has_to_change, option, min, max)¶Parameters: |
|
---|---|
Returns: |
|
The period is the period with which the CALLBACK_POWER
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_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 following constants are available for this function:
For option:
BrickletVoltageCurrentV2.
get_power_callback_configuration
()¶Return Object: |
|
---|
Returns the callback configuration as set by set_power_callback_configuration()
.
The following constants are available for this function:
For option:
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_v2.register_callback(BrickletVoltageCurrentV2.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.
BrickletVoltageCurrentV2.
CALLBACK_CURRENT
¶Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
set_current_callback_configuration()
.
The parameter is the same as get_current()
.
BrickletVoltageCurrentV2.
CALLBACK_VOLTAGE
¶Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
set_voltage_callback_configuration()
.
The parameter is the same as get_voltage()
.
BrickletVoltageCurrentV2.
CALLBACK_POWER
¶Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
set_power_callback_configuration()
.
The parameter is the same as get_power()
.
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.
BrickletVoltageCurrentV2.
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.
BrickletVoltageCurrentV2.
get_response_expected
(function_id)¶Parameters: |
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---|---|
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:
BrickletVoltageCurrentV2.
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:
BrickletVoltageCurrentV2.
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.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
BrickletVoltageCurrentV2.
set_bootloader_mode
(mode)¶Parameters: |
|
---|---|
Returns: |
|
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:
For mode:
For status:
BrickletVoltageCurrentV2.
get_bootloader_mode
()¶Returns: |
|
---|
Returns the current bootloader mode, see set_bootloader_mode()
.
The following constants are available for this function:
For mode:
BrickletVoltageCurrentV2.
set_write_firmware_pointer
(pointer)¶Parameters: |
|
---|---|
Returns: |
|
Sets the firmware pointer for write_firmware()
. 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.
BrickletVoltageCurrentV2.
write_firmware
(data)¶Parameters: |
|
---|---|
Returns: |
|
Writes 64 Bytes of firmware at the position as written by
set_write_firmware_pointer()
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.
BrickletVoltageCurrentV2.
write_uid
(uid)¶Parameters: |
|
---|---|
Returns: |
|
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.
BrickletVoltageCurrentV2.
read_uid
()¶Returns: |
|
---|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
BrickletVoltageCurrentV2.
DEVICE_IDENTIFIER
¶This constant is used to identify a Voltage/Current Bricklet 2.0.
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.
BrickletVoltageCurrentV2.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Voltage/Current Bricklet 2.0.