MQTT - DMX Bricklet¶

Simple¶

Download (example-simple.txt)

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# Change XYZ to the UID of your DMX Bricklet

setup:
    # Configure Bricklet as DMX master
    publish '{"dmx_mode": "master"}' to tinkerforge/request/dmx_bricklet/XYZ/set_dmx_mode

    # Write DMX frame with 3 channels
    publish '{"frame": [255,128,0]}' to tinkerforge/request/dmx_bricklet/XYZ/write_frame

Basic Functions¶

request/dmx_bricklet/<UID>/set_dmx_mode¶

Request:	dmx_mode – Type: int, Range: See symbols, Default: 0
Response:	no response

Sets the DMX mode to either master or slave.

Calling this function sets frame number to 0.

The following symbols are available for this function:

For dmx_mode:

• "master" = 0
• "slave" = 1

request/dmx_bricklet/<UID>/get_dmx_mode¶

Request:	empty payload
Response:	dmx_mode – Type: int, Range: See symbols, Default: 0

Returns the DMX mode, as set by request/dmx_bricklet/<UID>/set_dmx_mode.

The following symbols are available for this function:

For dmx_mode:

• "master" = 0
• "slave" = 1

request/dmx_bricklet/<UID>/write_frame¶

Request:	frame – Type: [int, ...], Length: variable, Range: [0 to 255]
Response:	no response

Writes a DMX frame. The maximum frame size is 512 byte. Each byte represents one channel.

The next frame can be written after the register/dmx_bricklet/<UID>/frame_started callback was called. The frame is double buffered, so a new frame can be written as soon as the writing of the prior frame starts.

The data will be transfered when the next frame duration ends, see request/dmx_bricklet/<UID>/set_frame_duration.

Generic approach:

• Set the frame duration to a value that represents the number of frames per second you want to achieve.
• Set channels for first frame.
• Wait for the register/dmx_bricklet/<UID>/frame_started callback.
• Set channels for next frame.
• Wait for the register/dmx_bricklet/<UID>/frame_started callback.
• and so on.

This approach ensures that you can set new DMX data with a fixed frame rate.

This function can only be called in master mode.

request/dmx_bricklet/<UID>/read_frame¶

Request:	empty payload
Response:	frame – Type: [int, ...], Length: variable, Range: [0 to 255] frame_number – Type: int, Range: [0 to 232 - 1]

Returns the last frame that was written by the DMX master. The size of the array is equivalent to the number of channels in the frame. Each byte represents one channel.

The next frame is available after the register/dmx_bricklet/<UID>/frame_available callback was called.

Generic approach:

• Call request/dmx_bricklet/<UID>/read_frame to get first frame.
• Wait for the register/dmx_bricklet/<UID>/frame_available callback.
• Call request/dmx_bricklet/<UID>/read_frame to get second frame.
• Wait for the register/dmx_bricklet/<UID>/frame_available callback.
• and so on.

Instead of polling this function you can also use the register/dmx_bricklet/<UID>/frame callback. You can enable it with request/dmx_bricklet/<UID>/set_frame_callback_config.

The frame number starts at 0 and it is increased by one with each received frame.

This function can only be called in slave mode.

request/dmx_bricklet/<UID>/set_frame_duration¶

Request:	frame_duration – Type: int, Unit: 1 ms, Range: [0 to 216 - 1], Default: 100
Response:	no response

Sets the duration of a frame.

Example: If you want to achieve 20 frames per second, you should set the frame duration to 50ms (50ms * 20 = 1 second).

If you always want to send a frame as fast as possible you can set this value to 0.

This setting is only used in master mode.

request/dmx_bricklet/<UID>/get_frame_duration¶

Request:	empty payload
Response:	frame_duration – Type: int, Unit: 1 ms, Range: [0 to 216 - 1], Default: 100

Returns the frame duration as set by request/dmx_bricklet/<UID>/set_frame_duration.

Advanced Functions¶

request/dmx_bricklet/<UID>/get_frame_error_count¶

Request:	empty payload
Response:	overrun_error_count – Type: int, Range: [0 to 232 - 1] framing_error_count – Type: int, Range: [0 to 232 - 1]

Returns the current number of overrun and framing errors.

request/dmx_bricklet/<UID>/set_communication_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

Sets the communication LED configuration. By default the LED shows communication traffic, 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 off.

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_communication" = 3

request/dmx_bricklet/<UID>/get_communication_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/dmx_bricklet/<UID>/set_communication_led_config

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_communication" = 3

request/dmx_bricklet/<UID>/set_error_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

Sets the error LED configuration.

By default the error LED turns on if there is any error (see register/dmx_bricklet/<UID>/frame_error_count callback). If you call this function with the Show-Error option again, the LED will turn off until the next error occurs.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is off.

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_error" = 3

request/dmx_bricklet/<UID>/get_error_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/dmx_bricklet/<UID>/set_error_led_config.

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_error" = 3

request/dmx_bricklet/<UID>/get_spitfp_error_count¶

Request:	empty payload
Response:	error_count_ack_checksum – Type: int, Range: [0 to 232 - 1] error_count_message_checksum – Type: int, Range: [0 to 232 - 1] error_count_frame – Type: int, Range: [0 to 232 - 1] error_count_overflow – Type: int, Range: [0 to 232 - 1]

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/dmx_bricklet/<UID>/set_status_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

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
• "show_heartbeat" = 2
• "show_status" = 3

request/dmx_bricklet/<UID>/get_status_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

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

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_status" = 3

request/dmx_bricklet/<UID>/get_chip_temperature¶

Request:	empty payload
Response:	temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

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.

request/dmx_bricklet/<UID>/reset¶

Request:	empty payload
Response:	no response

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/dmx_bricklet/<UID>/get_identity¶

Request:

empty payload

Response:

uid – Type: string, Length: up to 8 connected_uid – Type: string, Length: up to 8 position – Type: char, Range: ["a" to "h", "z"] hardware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] firmware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] device_identifier – Type: int, Range: [0 to 216 - 1] _display_name – Type: 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', '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. 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 DMX's name in a human readable form.

Callback Configuration Functions¶

request/dmx_bricklet/<UID>/set_frame_callback_config¶

Request:	frame_started_callback_enabled – Type: bool, Default: true frame_available_callback_enabled – Type: bool, Default: true frame_callback_enabled – Type: bool, Default: false frame_error_count_callback_enabled – Type: bool, Default: false
Response:	no response

Enables/Disables the different callbacks. By default the register/dmx_bricklet/<UID>/frame_started callback and register/dmx_bricklet/<UID>/frame_available callback are enabled while the register/dmx_bricklet/<UID>/frame callback and register/dmx_bricklet/<UID>/frame_error_count callback are disabled.

If you want to use the register/dmx_bricklet/<UID>/frame callback you can enable it and disable the register/dmx_bricklet/<UID>/frame_available callback at the same time. It becomes redundant in this case.

request/dmx_bricklet/<UID>/get_frame_callback_config¶

Request:	empty payload
Response:	frame_started_callback_enabled – Type: bool, Default: true frame_available_callback_enabled – Type: bool, Default: true frame_callback_enabled – Type: bool, Default: false frame_error_count_callback_enabled – Type: bool, Default: false

Returns the frame callback config as set by request/dmx_bricklet/<UID>/set_frame_callback_config.

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.

register/dmx_bricklet/<UID>/frame_started¶

Register Request:	register – Type: bool
Callback Response:	empty payload

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

This callback is triggered as soon as a new frame write is started. You should send the data for the next frame directly after this callback was triggered.

For an explanation of the general approach see request/dmx_bricklet/<UID>/write_frame.

This callback can be enabled via request/dmx_bricklet/<UID>/set_frame_callback_config.

This callback can only be triggered in master mode.

register/dmx_bricklet/<UID>/frame_available¶

Register Request:	register – Type: bool
Callback Response:	frame_number – Type: int, Range: [0 to 232 - 1]

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

This callback is triggered in slave mode when a new frame was received from the DMX master and it can be read out. You have to read the frame before the master has written the next frame, see request/dmx_bricklet/<UID>/read_frame for more details.

The parameter is the frame number, it is increased by one with each received frame.

This callback can be enabled via request/dmx_bricklet/<UID>/set_frame_callback_config.

This callback can only be triggered in slave mode.

register/dmx_bricklet/<UID>/frame¶

Register Request:	register – Type: bool
Callback Response:	frame – Type: [int, ...], Length: variable, Range: [0 to 255] frame_number – Type: int, Range: [0 to 232 - 1]

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

This callback is called as soon as a new frame is available (written by the DMX master).

The size of the array is equivalent to the number of channels in the frame. Each byte represents one channel.

This callback can be enabled via request/dmx_bricklet/<UID>/set_frame_callback_config.

This callback can only be triggered in slave mode.

Note

If reconstructing the value fails, the callback is triggered with null for frame.

register/dmx_bricklet/<UID>/frame_error_count¶

Register Request:	register – Type: bool
Callback Response:	overrun_error_count – Type: int, Range: [0 to 232 - 1] framing_error_count – Type: int, Range: [0 to 232 - 1]

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

This callback is called if a new error occurs. It returns the current overrun and framing error count.

Internal Functions¶

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.

request/dmx_bricklet/<UID>/set_bootloader_mode¶

Request:	mode – Type: int, Range: See symbols
Response:	status – Type: int, Range: See 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
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

For status:

• "ok" = 0
• "invalid_mode" = 1
• "no_change" = 2
• "entry_function_not_present" = 3
• "device_identifier_incorrect" = 4
• "crc_mismatch" = 5

request/dmx_bricklet/<UID>/get_bootloader_mode¶

Request:	empty payload
Response:	mode – Type: int, Range: See symbols

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

The following symbols are available for this function:

For mode:

• "bootloader" = 0
• "firmware" = 1
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

request/dmx_bricklet/<UID>/set_write_firmware_pointer¶

Request:	pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Response:	no response

Sets the firmware pointer for request/dmx_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/dmx_bricklet/<UID>/write_firmware¶

Request:	data – Type: [int, ...], Length: 64, Range: [0 to 255]
Response:	status – Type: int, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by request/dmx_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/dmx_bricklet/<UID>/write_uid¶

Request:	uid – Type: int, Range: [0 to 232 - 1]
Response:	no response

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/dmx_bricklet/<UID>/read_uid¶

Request:	empty payload
Response:	uid – Type: int, Range: [0 to 232 - 1]

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