MQTT - Color Bricklet

This is the description of the MQTT 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 MQTT API bindings is part of their general description.

Examples

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

Simple

Download (example-simple.txt)

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# Change XYZ to the UID of your Color Bricklet

setup:
    # Get current color
    subscribe to tinkerforge/response/color_bricklet/XYZ/get_color
    publish '' to tinkerforge/request/color_bricklet/XYZ/get_color

Callback

Download (example-callback.txt)

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# Change XYZ to the UID of your Color Bricklet

setup:
    # Handle incoming color callbacks
    subscribe to tinkerforge/callback/color_bricklet/XYZ/color
    publish '{"register": true}' to tinkerforge/register/color_bricklet/XYZ/color # Register color callback
    
    # 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!
    publish '{"period": 1000}' to tinkerforge/request/color_bricklet/XYZ/set_color_callback_period

Threshold

Download (example-threshold.txt)

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# Change XYZ to the UID of your Color Bricklet

setup:
    # Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    publish '{"debounce": 10000}' to tinkerforge/request/color_bricklet/XYZ/set_debounce_period
    
    # Handle incoming color reached callbacks
    subscribe to tinkerforge/callback/color_bricklet/XYZ/color_reached
    publish '{"register": true}' to tinkerforge/register/color_bricklet/XYZ/color_reached # Register color_reached callback
    
    # Configure threshold for color "greater than 100, 200, 300, 400"
    publish '{"option": "greater", "min_r": 100, "max_r": 0, "min_g": 200, "max_g": 0, "min_b": 300, "max_b": 0, "min_c": 400, "max_c": 0}' to tinkerforge/request/color_bricklet/XYZ/set_color_callback_threshold

API

All published payloads to and from the MQTT bindings are in JSON format.

If an error occures, the bindings publish a JSON object containing the error message as attribute "_ERROR". It is published on the corresponding response topic: .../response/... for .../request/... and .../callback/... for .../register/....

Basic Functions

request/color_bricklet/<UID>/get_color
Response payload:
  • r -- int
  • g -- int
  • b -- int
  • c -- 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 register/color_bricklet/<UID>/color callback and set the period with request/color_bricklet/<UID>/set_color_callback_period.

request/color_bricklet/<UID>/light_on

Turns the LED on.

request/color_bricklet/<UID>/light_off

Turns the LED off.

request/color_bricklet/<UID>/is_light_on
Response payload:
  • light -- int (has symbols)

Returns the state of the LED. Possible values are:

  • 0: On
  • 1: Off

The following symbols are available for this function:

for light:

  • "On" = 0
  • "Off" = 1
request/color_bricklet/<UID>/set_config
Request payload:
  • gain -- int (has symbols)
  • integration_time -- int (has symbols)

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 symbols are available for this function:

for gain:

  • "1x" = 0
  • "4x" = 1
  • "16x" = 2
  • "60x" = 3

for integration_time:

  • "2ms" = 0
  • "24ms" = 1
  • "101ms" = 2
  • "154ms" = 3
  • "700ms" = 4
request/color_bricklet/<UID>/get_config
Response payload:
  • gain -- int (has symbols)
  • integration_time -- int (has symbols)

Returns the configuration as set by request/color_bricklet/<UID>/set_config.

The following symbols are available for this function:

for gain:

  • "1x" = 0
  • "4x" = 1
  • "16x" = 2
  • "60x" = 3

for integration_time:

  • "2ms" = 0
  • "24ms" = 1
  • "101ms" = 2
  • "154ms" = 3
  • "700ms" = 4
request/color_bricklet/<UID>/get_illuminance
Response payload:
  • illuminance -- int

Returns the illuminance affected by the gain and integration time as set by request/color_bricklet/<UID>/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 themselves 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 request/color_bricklet/<UID>/set_config.

request/color_bricklet/<UID>/get_color_temperature
Response payload:
  • color_temperature -- int

Returns the color temperature in Kelvin.

To get a correct color temperature measurement make sure that the color values themselves 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 request/color_bricklet/<UID>/set_config.

Advanced Functions

request/color_bricklet/<UID>/get_identity
Response payload:
  • uid -- string
  • connected_uid -- string
  • position -- char
  • hardware_version -- [int,int,int]
  • firmware_version -- [int,int,int]
  • device_identifier -- int (has symbols)
  • _display_name -- string

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. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the Color's name in a human readable form.

Callback Configuration Functions

request/color_bricklet/<UID>/set_color_callback_period
Request payload:
  • period -- int

Sets the period in ms with which the register/color_bricklet/<UID>/color callback is triggered periodically. A value of 0 turns the callback off.

The register/color_bricklet/<UID>/color callback is only triggered if the color has changed since the last triggering.

The default value is 0.

request/color_bricklet/<UID>/get_color_callback_period
Response payload:
  • period -- int

Returns the period as set by request/color_bricklet/<UID>/set_color_callback_period.

request/color_bricklet/<UID>/set_color_callback_threshold
Request payload:
  • option -- char (has symbols)
  • min_r -- int
  • max_r -- int
  • min_g -- int
  • max_g -- int
  • min_b -- int
  • max_b -- int
  • min_c -- int
  • max_c -- int

Sets the thresholds for the register/color_bricklet/<UID>/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 symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/color_bricklet/<UID>/get_color_callback_threshold
Response payload:
  • option -- char (has symbols)
  • min_r -- int
  • max_r -- int
  • min_g -- int
  • max_g -- int
  • min_b -- int
  • max_b -- int
  • min_c -- int
  • max_c -- int

Returns the threshold as set by request/color_bricklet/<UID>/set_color_callback_threshold.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/color_bricklet/<UID>/set_debounce_period
Request payload:
  • debounce -- int

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

request/color_bricklet/<UID>/get_debounce_period
Response payload:
  • debounce -- int

Returns the debounce period as set by request/color_bricklet/<UID>/set_debounce_period.

request/color_bricklet/<UID>/set_illuminance_callback_period
Request payload:
  • period -- int

Sets the period in ms with which the register/color_bricklet/<UID>/illuminance callback is triggered periodically. A value of 0 turns the callback off.

The register/color_bricklet/<UID>/illuminance callback is only triggered if the illuminance has changed since the last triggering.

The default value is 0.

request/color_bricklet/<UID>/get_illuminance_callback_period
Response payload:
  • period -- int

Returns the period as set by request/color_bricklet/<UID>/set_illuminance_callback_period.

request/color_bricklet/<UID>/set_color_temperature_callback_period
Request payload:
  • period -- int

Sets the period in ms with which the register/color_bricklet/<UID>/color_temperature callback is triggered periodically. A value of 0 turns the callback off.

The register/color_bricklet/<UID>/color_temperature callback is only triggered if the color temperature has changed since the last triggering.

The default value is 0.

request/color_bricklet/<UID>/get_color_temperature_callback_period
Response payload:
  • period -- int

Returns the period as set by request/color_bricklet/<UID>/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 corresponding .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

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.

register/color_bricklet/<UID>/color
Request payload:
  • register -- bool
Response payload:
  • r -- int
  • g -- int
  • b -- int
  • c -- int

A callback can be registered for this event by publishing to the .../register/color_bricklet/<UID>/color[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/color_bricklet/<UID>/color[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/color_bricklet/<UID>/set_color_callback_period. The callback payload is the color of the sensor as RGBC.

The register/color_bricklet/<UID>/color callback is only triggered if the color has changed since the last triggering.

register/color_bricklet/<UID>/color_reached
Request payload:
  • register -- bool
Response payload:
  • r -- int
  • g -- int
  • b -- int
  • c -- int

A callback can be registered for this event by publishing to the .../register/color_bricklet/<UID>/color_reached[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/color_bricklet/<UID>/color_reached[/<SUFFIX>] topic for each registered suffix.

This callback is triggered when the threshold as set by request/color_bricklet/<UID>/set_color_callback_threshold is reached. The callback payload 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 request/color_bricklet/<UID>/set_debounce_period.

register/color_bricklet/<UID>/illuminance
Request payload:
  • register -- bool
Response payload:
  • illuminance -- int

A callback can be registered for this event by publishing to the .../register/color_bricklet/<UID>/illuminance[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/color_bricklet/<UID>/illuminance[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/color_bricklet/<UID>/set_illuminance_callback_period. The callback payload is the illuminance. See request/color_bricklet/<UID>/get_illuminance for how to interpret this value.

The register/color_bricklet/<UID>/illuminance callback is only triggered if the illuminance has changed since the last triggering.

register/color_bricklet/<UID>/color_temperature
Request payload:
  • register -- bool
Response payload:
  • color_temperature -- int

A callback can be registered for this event by publishing to the .../register/color_bricklet/<UID>/color_temperature[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/color_bricklet/<UID>/color_temperature[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/color_bricklet/<UID>/set_color_temperature_callback_period. The callback payload is the color temperature in Kelvin.

The register/color_bricklet/<UID>/color_temperature callback is only triggered if the color temperature has changed since the last triggering.