MQTT - Isolator Bricklet

This is the description of the MQTT API bindings for the Isolator Bricklet. General information and technical specifications for the Isolator 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 Isolator Bricklet

setup:
    # Get current statistics
    subscribe to tinkerforge/response/isolator_bricklet/XYZ/get_statistics
    publish '' to tinkerforge/request/isolator_bricklet/XYZ/get_statistics

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/isolator_bricklet/<UID>/get_statistics
Response payload:
 
  • messages_from_brick -- int
  • messages_from_bricklet -- int
  • connected_bricklet_device_identifier -- int
  • connected_bricklet_uid -- string

Returns statistics for the Isolator Bricklet.

Advanced Functions

request/isolator_bricklet/<UID>/set_spitfp_baudrate_config
Request payload:
 
  • enable_dynamic_baudrate -- bool
  • minimum_dynamic_baudrate -- int

The SPITF protocol can be used with a dynamic baudrate. If the dynamic baudrate is enabled, the Isolator Bricklet will try to adapt the baudrate for the communication between Bricks and Bricklets according to the amount of data that is transferred.

The baudrate for communication config between Brick and Isolator Bricklet can be set through the API of the Brick.

The baudrate will be increased exponentially if lots of data is send/received and decreased linearly if little data is send/received.

This lowers the baudrate in applications where little data is transferred (e.g. a weather station) and increases the robustness. If there is lots of data to transfer (e.g. Thermal Imaging Bricklet) it automatically increases the baudrate as needed.

In cases where some data has to transferred as fast as possible every few seconds (e.g. RS485 Bricklet with a high baudrate but small payload) you may want to turn the dynamic baudrate off to get the highest possible performance.

The maximum value of the baudrate can be set per port with the function request/isolator_bricklet/<UID>/set_spitfp_baudrate. If the dynamic baudrate is disabled, the baudrate as set by request/isolator_bricklet/<UID>/set_spitfp_baudrate will be used statically.

The minimum dynamic baudrate has a value range of 400000 to 2000000 baud.

By default dynamic baudrate is enabled and the minimum dynamic baudrate is 400000.

request/isolator_bricklet/<UID>/get_spitfp_baudrate_config
Response payload:
 
  • enable_dynamic_baudrate -- bool
  • minimum_dynamic_baudrate -- int

Returns the baudrate config, see request/isolator_bricklet/<UID>/set_spitfp_baudrate_config.

request/isolator_bricklet/<UID>/set_spitfp_baudrate
Request payload:
 
  • baudrate -- int

Sets the baudrate for a the communication between Isolator Bricklet and the connected Bricklet. The baudrate for communication between Brick and Isolator Bricklet can be set through the API of the Brick.

The baudrate can be in the range 400000 to 2000000.

If you want to increase the throughput of Bricklets you can increase the baudrate. If you get a high error count because of high interference (see request/isolator_bricklet/<UID>/get_spitfp_error_count) you can decrease the baudrate.

If the dynamic baudrate feature is enabled, the baudrate set by this function corresponds to the maximum baudrate (see request/isolator_bricklet/<UID>/set_spitfp_baudrate_config).

Regulatory testing is done with the default baudrate. If CE compatibility or similar is necessary in you applications we recommend to not change the baudrate.

The default baudrate for all ports is 1400000.

request/isolator_bricklet/<UID>/get_spitfp_baudrate
Response payload:
 
  • baudrate -- int

Returns the baudrate, see request/isolator_bricklet/<UID>/set_spitfp_baudrate.

request/isolator_bricklet/<UID>/get_isolator_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 Isolator Bricklet and the connected Bricklet. Call request/isolator_bricklet/<UID>/get_spitfp_error_count to get the error count between Isolator Bricklet and Brick.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.
request/isolator_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/isolator_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/isolator_bricklet/<UID>/get_bootloader_mode
Response payload:
 
  • mode -- int (has symbols)

Returns the current bootloader mode, see request/isolator_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/isolator_bricklet/<UID>/set_write_firmware_pointer
Request payload:
 
  • pointer -- int

Sets the firmware pointer for request/isolator_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/isolator_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/isolator_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/isolator_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/isolator_bricklet/<UID>/get_status_led_config
Response payload:
 
  • config -- int (has symbols)

Returns the configuration as set by request/isolator_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/isolator_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/isolator_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/isolator_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/isolator_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/isolator_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 Isolator's name in a human readable form.