MQTT - UV Light Bricklet 2.0

This is the description of the MQTT API bindings for the UV Light Bricklet 2.0. General information and technical specifications for the UV Light Bricklet 2.0 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).

Callback

Download (example-callback.txt)

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# Change XYZ to the UID of your UV Light Bricklet 2.0

setup:
    # Handle incoming UV index callbacks
    subscribe to tinkerforge/callback/uv_light_v2_bricklet/XYZ/uvi
    publish '{"register": true}' to tinkerforge/register/uv_light_v2_bricklet/XYZ/uvi # Register uvi callback
    
    # Set period for UVI callback to 1s (1000ms) without a threshold
    publish '{"period": 1000, "value_has_to_change": false, "option": "off", "min": 0, "max": 0}' to tinkerforge/request/uv_light_v2_bricklet/XYZ/set_uvi_callback_configuration

Threshold

Download (example-threshold.txt)

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# Change XYZ to the UID of your UV Light Bricklet 2.0

setup:
    # Handle incoming UV index callbacks
    subscribe to tinkerforge/callback/uv_light_v2_bricklet/XYZ/uvi
    publish '{"register": true}' to tinkerforge/register/uv_light_v2_bricklet/XYZ/uvi # Register uvi callback
    
    # Configure threshold for UV index "greater than 3"
    # with a debounce period of 1s (1000ms)
    publish '{"period": 1000, "value_has_to_change": false, "option": "greater", "min": 30, "max": 0}' to tinkerforge/request/uv_light_v2_bricklet/XYZ/set_uvi_callback_configuration

Simple

Download (example-simple.txt)

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# Change XYZ to the UID of your UV Light Bricklet 2.0

setup:
    # Get current UV-A
    subscribe to tinkerforge/response/uv_light_v2_bricklet/XYZ/get_uva
    publish '' to tinkerforge/request/uv_light_v2_bricklet/XYZ/get_uva
    
    # Get current UV-B
    subscribe to tinkerforge/response/uv_light_v2_bricklet/XYZ/get_uvb
    publish '' to tinkerforge/request/uv_light_v2_bricklet/XYZ/get_uvb
    
    # Get current UV index
    subscribe to tinkerforge/response/uv_light_v2_bricklet/XYZ/get_uvi
    publish '' to tinkerforge/request/uv_light_v2_bricklet/XYZ/get_uvi

API

All published payload to an from the MQTT bindings is in the 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/uv_light_v2_bricklet/<UID>/get_uva
Response payload:
 
  • uva -- int

Returns the UVA intensity of the sensor, the intensity is given in 1/10 mW/m². The sensor has not weighted the intensity with the erythemal action spectrum to get the skin-affecting irradiation. Therefore, you cannot just divide the value by 250 to get the UVA index. To get the UV index use request/uv_light_v2_bricklet/<UID>/get_uvi.

If the sensor is saturated, then -1 is returned, see request/uv_light_v2_bricklet/<UID>/set_configuration.

If you want to get the intensity periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uva callback and set the period with request/uv_light_v2_bricklet/<UID>/set_uva_callback_configuration.

If you want to get the value periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uva callback. You can set the callback configuration with request/uv_light_v2_bricklet/<UID>/set_uva_callback_configuration.

request/uv_light_v2_bricklet/<UID>/get_uvb
Response payload:
 
  • uvb -- int

Returns the UVB intensity of the sensor, the intensity is given in 1/10 mW/m². The sensor has not weighted the intensity with the erythemal action spectrum to get the skin-affecting irradiation. Therefore, you cannot just divide the value by 250 to get the UVB index. To get the UV index use request/uv_light_v2_bricklet/<UID>/get_uvi.

If the sensor is saturated, then -1 is returned, see request/uv_light_v2_bricklet/<UID>/set_configuration.

If you want to get the intensity periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uvb callback and set the period with request/uv_light_v2_bricklet/<UID>/set_uvb_callback_configuration.

If you want to get the value periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uvb callback. You can set the callback configuration with request/uv_light_v2_bricklet/<UID>/set_uvb_callback_configuration.

request/uv_light_v2_bricklet/<UID>/get_uvi
Response payload:
 
  • uvi -- int

Returns the UV index of the sensor, the index is given in 1/10.

If the sensor is saturated, then -1 is returned, see request/uv_light_v2_bricklet/<UID>/set_configuration.

If you want to get the intensity periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uvi callback and set the period with request/uv_light_v2_bricklet/<UID>/set_uvi_callback_configuration.

If you want to get the value periodically, it is recommended to use the register/uv_light_v2_bricklet/<UID>/uvi callback. You can set the callback configuration with request/uv_light_v2_bricklet/<UID>/set_uvi_callback_configuration.

Advanced Functions

request/uv_light_v2_bricklet/<UID>/set_configuration
Request payload:
 
  • integration_time -- int (has symbols)

Sets the configuration of the sensor. The integration time can be configured between 50 and 800 ms. With a shorter integration time the sensor reading updates more often but contains more noise. With a longer integration the sensor reading contains less noise but updates less often.

With a longer integration time (especially 800 ms) and a higher UV intensity the sensor can be saturated. If this happens the UVA/UVB/UVI readings are all -1. In this case you need to choose a shorter integration time.

Default value: 400 ms.

The following symbols are available for this function:

for integration_time:

  • "50ms" = 0
  • "100ms" = 1
  • "200ms" = 2
  • "400ms" = 3
  • "800ms" = 4
request/uv_light_v2_bricklet/<UID>/get_configuration
Response payload:
 
  • integration_time -- int (has symbols)

Returns the configuration as set by request/uv_light_v2_bricklet/<UID>/set_configuration.

The following symbols are available for this function:

for integration_time:

  • "50ms" = 0
  • "100ms" = 1
  • "200ms" = 2
  • "400ms" = 3
  • "800ms" = 4
request/uv_light_v2_bricklet/<UID>/get_spitfp_error_count
Response payload:
 
  • error_count_ack_checksum -- int
  • error_count_message_checksum -- int
  • error_count_frame -- int
  • error_count_overflow -- int

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.

request/uv_light_v2_bricklet/<UID>/set_bootloader_mode
Request payload:
 
  • mode -- int (has symbols)
Response payload:
 
  • status -- int (has symbols)

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 symbols are available for this function:

for mode:

  • "Bootloader" = 0
  • "Firmware" = 1
  • "BootloaderWaitForReboot" = 2
  • "FirmwareWaitForReboot" = 3
  • "FirmwareWaitForEraseAndReboot" = 4

for status:

  • "OK" = 0
  • "InvalidMode" = 1
  • "NoChange" = 2
  • "EntryFunctionNotPresent" = 3
  • "DeviceIdentifierIncorrect" = 4
  • "CRCMismatch" = 5
request/uv_light_v2_bricklet/<UID>/get_bootloader_mode
Response payload:
 
  • mode -- int (has symbols)

Returns the current bootloader mode, see request/uv_light_v2_bricklet/<UID>/set_bootloader_mode.

The following symbols are available for this function:

for mode:

  • "Bootloader" = 0
  • "Firmware" = 1
  • "BootloaderWaitForReboot" = 2
  • "FirmwareWaitForReboot" = 3
  • "FirmwareWaitForEraseAndReboot" = 4
request/uv_light_v2_bricklet/<UID>/set_write_firmware_pointer
Request payload:
 
  • pointer -- int

Sets the firmware pointer for request/uv_light_v2_bricklet/<UID>/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.

request/uv_light_v2_bricklet/<UID>/write_firmware
Request payload:
 
  • data -- [int,... (x64)]
Response payload:
 
  • status -- int

Writes 64 Bytes of firmware at the position as written by request/uv_light_v2_bricklet/<UID>/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.

request/uv_light_v2_bricklet/<UID>/set_status_led_config
Request payload:
 
  • config -- int (has symbols)

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 symbols are available for this function:

for config:

  • "Off" = 0
  • "On" = 1
  • "ShowHeartbeat" = 2
  • "ShowStatus" = 3
request/uv_light_v2_bricklet/<UID>/get_status_led_config
Response payload:
 
  • config -- int (has symbols)

Returns the configuration as set by request/uv_light_v2_bricklet/<UID>/set_status_led_config

The following symbols are available for this function:

for config:

  • "Off" = 0
  • "On" = 1
  • "ShowHeartbeat" = 2
  • "ShowStatus" = 3
request/uv_light_v2_bricklet/<UID>/get_chip_temperature
Response payload:
 
  • temperature -- int

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.

request/uv_light_v2_bricklet/<UID>/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!

request/uv_light_v2_bricklet/<UID>/write_uid
Request payload:
 
  • uid -- int

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.

request/uv_light_v2_bricklet/<UID>/read_uid
Response payload:
 
  • uid -- int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

request/uv_light_v2_bricklet/<UID>/get_identity
Response payload:
 
  • uid -- string
  • connected_uid -- string
  • position -- string
  • 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 UV Light 2.0's name in a human readable form.

Callback Configuration Functions

request/uv_light_v2_bricklet/<UID>/set_uva_callback_configuration
Request payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

The period in ms is the period with which the register/uv_light_v2_bricklet/<UID>/uva 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 register/uv_light_v2_bricklet/<UID>/uva 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 symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/uv_light_v2_bricklet/<UID>/get_uva_callback_configuration
Response payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

Returns the callback configuration as set by request/uv_light_v2_bricklet/<UID>/set_uva_callback_configuration.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/uv_light_v2_bricklet/<UID>/set_uvb_callback_configuration
Request payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

The period in ms is the period with which the register/uv_light_v2_bricklet/<UID>/uvb 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 register/uv_light_v2_bricklet/<UID>/uvb 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 symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/uv_light_v2_bricklet/<UID>/get_uvb_callback_configuration
Response payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

Returns the callback configuration as set by request/uv_light_v2_bricklet/<UID>/set_uvb_callback_configuration.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/uv_light_v2_bricklet/<UID>/set_uvi_callback_configuration
Request payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

The period in ms is the period with which the register/uv_light_v2_bricklet/<UID>/uvi 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 register/uv_light_v2_bricklet/<UID>/uvi 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 symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'
request/uv_light_v2_bricklet/<UID>/get_uvi_callback_configuration
Response payload:
 
  • period -- int
  • value_has_to_change -- bool
  • option -- string (has symbols)
  • min -- int
  • max -- int

Returns the callback configuration as set by request/uv_light_v2_bricklet/<UID>/set_uvi_callback_configuration.

The following symbols are available for this function:

for option:

  • "Off" = 'x'
  • "Outside" = 'o'
  • "Inside" = 'i'
  • "Smaller" = '<'
  • "Greater" = '>'

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/uv_light_v2_bricklet/<UID>/uva
Request payload:
 
  • register -- bool
Response payload:
 
  • uva -- int

A callback can be registered for this event by publishing to the .../register/uv_light_v2_bricklet/<UID>/uva[/<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/uv_light_v2_bricklet/<UID>/uva[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically according to the configuration set by request/uv_light_v2_bricklet/<UID>/set_uva_callback_configuration.

The callback payload is the same as request/uv_light_v2_bricklet/<UID>/get_uva.

register/uv_light_v2_bricklet/<UID>/uvb
Request payload:
 
  • register -- bool
Response payload:
 
  • uvb -- int

A callback can be registered for this event by publishing to the .../register/uv_light_v2_bricklet/<UID>/uvb[/<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/uv_light_v2_bricklet/<UID>/uvb[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically according to the configuration set by request/uv_light_v2_bricklet/<UID>/set_uvb_callback_configuration.

The callback payload is the same as request/uv_light_v2_bricklet/<UID>/get_uvb.

register/uv_light_v2_bricklet/<UID>/uvi
Request payload:
 
  • register -- bool
Response payload:
 
  • uvi -- int

A callback can be registered for this event by publishing to the .../register/uv_light_v2_bricklet/<UID>/uvi[/<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/uv_light_v2_bricklet/<UID>/uvi[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically according to the configuration set by request/uv_light_v2_bricklet/<UID>/set_uvi_callback_configuration.

The callback payload is the same as request/uv_light_v2_bricklet/<UID>/get_uvi.