Python - Color Bricklet

This is the description of the Python API bindings for the Color Bricklet. General information and technical specifications for the Color Bricklet are summarized in its hardware description.

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

Examples

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

Simple

Download (example_simple.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Color Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_color import BrickletColor

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    c = BrickletColor(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Get current color
    r, g, b, c_ = c.get_color()

    print("Color [R]: " + str(r))
    print("Color [G]: " + str(g))
    print("Color [B]: " + str(b))
    print("Color [C]: " + str(c_))

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Callback

Download (example_callback.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Color Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_color import BrickletColor

# Callback function for color callback
def cb_color(r, g, b, c):
    print("Color [R]: " + str(r))
    print("Color [G]: " + str(g))
    print("Color [B]: " + str(b))
    print("Color [C]: " + str(c))
    print("")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    c = BrickletColor(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Register color callback to function cb_color
    c.register_callback(c.CALLBACK_COLOR, cb_color)

    # Set period for color callback to 1s (1000ms)
    # Note: The color callback is only called every second
    #       if the color has changed since the last call!
    c.set_color_callback_period(1000)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Threshold

Download (example_threshold.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Color Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_color import BrickletColor

# Callback function for color reached callback
def cb_color_reached(r, g, b, c):
    print("Color [R]: " + str(r))
    print("Color [G]: " + str(g))
    print("Color [B]: " + str(b))
    print("Color [C]: " + str(c))
    print("")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    c = BrickletColor(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)
    c.set_debounce_period(10000)

    # Register color reached callback to function cb_color_reached
    c.register_callback(c.CALLBACK_COLOR_REACHED, cb_color_reached)

    # Configure threshold for color "greater than 100, 200, 300, 400"
    c.set_color_callback_threshold(">", 100, 0, 200, 0, 300, 0, 400, 0)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

API

Generally, every method 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:

  • Error.TIMEOUT = -1
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12

All methods listed below are thread-safe.

Basic Functions

BrickletColor(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

color = BrickletColor("YOUR_DEVICE_UID", ipcon)

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

BrickletColor.get_color()
Return type:(int, int, int, int)

Returns the measured color of the sensor. The values have a range of 0 to 65535.

The red (r), green (g), blue (b) and clear (c) colors are measured with four different photodiodes that are responsive at different wavelengths:

Chart Responsivity / Wavelength

If you want to get the color periodically, it is recommended to use the CALLBACK_COLOR callback and set the period with set_color_callback_period().

The returned namedtuple has the variables r, g, b and c.

BrickletColor.light_on()
Return type:None

Turns the LED on.

BrickletColor.light_off()
Return type:None

Turns the LED off.

BrickletColor.is_light_on()
Return type:int

Returns the state of the LED. Possible values are:

  • 0: On
  • 1: Off

The following constants are available for this function:

  • BrickletColor.LIGHT_ON = 0
  • BrickletColor.LIGHT_OFF = 1
BrickletColor.set_config(gain, integration_time)
Parameters:
  • gain -- int
  • integration_time -- int
Return type:

None

Sets the configuration of the sensor. Gain and integration time can be configured in this way.

For configuring the gain:

  • 0: 1x Gain
  • 1: 4x Gain
  • 2: 16x Gain
  • 3: 60x Gain

For configuring the integration time:

  • 0: 2.4ms
  • 1: 24ms
  • 2: 101ms
  • 3: 154ms
  • 4: 700ms

Increasing the gain enables the sensor to detect a color from a higher distance.

The integration time provides a trade-off between conversion time and accuracy. With a longer integration time the values read will be more accurate but it will take longer time to get the conversion results.

The default values are 60x gain and 154ms integration time.

The following constants are available for this function:

  • BrickletColor.GAIN_1X = 0
  • BrickletColor.GAIN_4X = 1
  • BrickletColor.GAIN_16X = 2
  • BrickletColor.GAIN_60X = 3
  • BrickletColor.INTEGRATION_TIME_2MS = 0
  • BrickletColor.INTEGRATION_TIME_24MS = 1
  • BrickletColor.INTEGRATION_TIME_101MS = 2
  • BrickletColor.INTEGRATION_TIME_154MS = 3
  • BrickletColor.INTEGRATION_TIME_700MS = 4
BrickletColor.get_config()
Return type:(int, int)

Returns the configuration as set by set_config().

The following constants are available for this function:

  • BrickletColor.GAIN_1X = 0
  • BrickletColor.GAIN_4X = 1
  • BrickletColor.GAIN_16X = 2
  • BrickletColor.GAIN_60X = 3
  • BrickletColor.INTEGRATION_TIME_2MS = 0
  • BrickletColor.INTEGRATION_TIME_24MS = 1
  • BrickletColor.INTEGRATION_TIME_101MS = 2
  • BrickletColor.INTEGRATION_TIME_154MS = 3
  • BrickletColor.INTEGRATION_TIME_700MS = 4

The returned namedtuple has the variables gain and integration_time.

BrickletColor.get_illuminance()
Return type:int

Returns the illuminance affected by the gain and integration time as set by set_config(). To get the illuminance in Lux apply this formula:

lux = illuminance * 700 / gain / integration_time

To get a correct illuminance measurement make sure that the color values themself are not saturated. The color value (R, G or B) is saturated if it is equal to the maximum value of 65535. In that case you have to reduce the gain, see set_config().

BrickletColor.get_color_temperature()
Return type:int

Returns the color temperature in Kelvin.

To get a correct color temperature measurement make sure that the color values themself are not saturated. The color value (R, G or B) is saturated if it is equal to the maximum value of 65535. In that case you have to reduce the gain, see set_config().

Advanced Functions

BrickletColor.get_api_version()
Return type:[int, int, int]

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.

BrickletColor.get_response_expected(function_id)
Parameters:function_id -- int
Return type:bool

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 send and errors are silently ignored, because they cannot be detected.

See set_response_expected() for the list of function ID constants available for this function.

BrickletColor.set_response_expected(function_id, response_expected)
Parameters:
  • function_id -- int
  • response_expected -- bool
Return type:

None

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 send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletColor.FUNCTION_SET_COLOR_CALLBACK_PERIOD = 2
  • BrickletColor.FUNCTION_SET_COLOR_CALLBACK_THRESHOLD = 4
  • BrickletColor.FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BrickletColor.FUNCTION_LIGHT_ON = 10
  • BrickletColor.FUNCTION_LIGHT_OFF = 11
  • BrickletColor.FUNCTION_SET_CONFIG = 13
  • BrickletColor.FUNCTION_SET_ILLUMINANCE_CALLBACK_PERIOD = 17
  • BrickletColor.FUNCTION_SET_COLOR_TEMPERATURE_CALLBACK_PERIOD = 19
BrickletColor.set_response_expected_all(response_expected)
Parameters:response_expected -- bool
Return type:None

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletColor.get_identity()
Return type:(str, str, chr, [int, int, int], [int, int, int], int)

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 namedtuple has the variables uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletColor.register_callback(callback_id, function)
Parameters:
  • callback_id -- int
  • function -- callable
Return type:

None

Registers the given function with the given callback_id.

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

BrickletColor.set_color_callback_period(period)
Parameters:period -- int
Return type:None

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

The CALLBACK_COLOR callback is only triggered if the color has changed since the last triggering.

The default value is 0.

BrickletColor.get_color_callback_period()
Return type:int

Returns the period as set by set_color_callback_period().

BrickletColor.set_color_callback_threshold(option, min_r, max_r, min_g, max_g, min_b, max_b, min_c, max_c)
Parameters:
  • option -- chr
  • min_r -- int
  • max_r -- int
  • min_g -- int
  • max_g -- int
  • min_b -- int
  • max_b -- int
  • min_c -- int
  • max_c -- int
Return type:

None

Sets the thresholds for the CALLBACK_COLOR_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 default value is ('x', 0, 0, 0, 0, 0, 0, 0, 0).

The following constants are available for this function:

  • BrickletColor.THRESHOLD_OPTION_OFF = 'x'
  • BrickletColor.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletColor.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletColor.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletColor.THRESHOLD_OPTION_GREATER = '>'
BrickletColor.get_color_callback_threshold()
Return type:(chr, int, int, int, int, int, int, int, int)

Returns the threshold as set by set_color_callback_threshold().

The following constants are available for this function:

  • BrickletColor.THRESHOLD_OPTION_OFF = 'x'
  • BrickletColor.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletColor.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletColor.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletColor.THRESHOLD_OPTION_GREATER = '>'

The returned namedtuple has the variables option, min_r, max_r, min_g, max_g, min_b, max_b, min_c and max_c.

BrickletColor.set_debounce_period(debounce)
Parameters:debounce -- int
Return type:None

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

BrickletColor.get_debounce_period()
Return type:int

Returns the debounce period as set by set_debounce_period().

BrickletColor.set_illuminance_callback_period(period)
Parameters:period -- int
Return type:None

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

The CALLBACK_ILLUMINANCE callback is only triggered if the illuminance has changed since the last triggering.

The default value is 0.

BrickletColor.get_illuminance_callback_period()
Return type:int

Returns the period as set by set_illuminance_callback_period().

BrickletColor.set_color_temperature_callback_period(period)
Parameters:period -- int
Return type:None

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

The CALLBACK_COLOR_TEMPERATURE callback is only triggered if the color temperature has changed since the last triggering.

The default value is 0.

BrickletColor.get_color_temperature_callback_period()
Return type:int

Returns the period as set by set_color_temperature_callback_period().

Callbacks

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)

color.register_callback(BrickletColor.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.

BrickletColor.CALLBACK_COLOR
Parameters:
  • r -- int
  • g -- int
  • b -- int
  • c -- int

This callback is triggered periodically with the period that is set by set_color_callback_period(). The parameter is the color of the sensor as RGBC.

The CALLBACK_COLOR callback is only triggered if the color has changed since the last triggering.

BrickletColor.CALLBACK_COLOR_REACHED
Parameters:
  • r -- int
  • g -- int
  • b -- int
  • c -- int

This callback is triggered when the threshold as set by set_color_callback_threshold() is reached. The parameter is the color of the sensor as RGBC.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set_debounce_period().

BrickletColor.CALLBACK_ILLUMINANCE
Parameters:illuminance -- int

This callback is triggered periodically with the period that is set by set_illuminance_callback_period(). The parameter is the illuminance. See get_illuminance() for how to interpret this value.

The CALLBACK_ILLUMINANCE callback is only triggered if the illuminance has changed since the last triggering.

BrickletColor.CALLBACK_COLOR_TEMPERATURE
Parameters:color_temperature -- int

This callback is triggered periodically with the period that is set by set_color_temperature_callback_period(). The parameter is the color temperature in Kelvin.

The CALLBACK_COLOR_TEMPERATURE callback is only triggered if the color temperature has changed since the last triggering.

Constants

BrickletColor.DEVICE_IDENTIFIER

This constant is used to identify a Color Bricklet.

The get_identity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletColor.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Color Bricklet.