MQTT - Industrial Digital In 4 Bricklet 2.0

This is the description of the MQTT API bindings for the Industrial Digital In 4 Bricklet 2.0. General information and technical specifications for the Industrial Digital In 4 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).

Simple

Download (example-simple.txt)

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# Change XYZ to the UID of your Industrial Digital In 4 Bricklet 2.0

setup:
    # Get current value
    subscribe to tinkerforge/response/industrial_digital_in_4_v2_bricklet/XYZ/get_value
    publish '' to tinkerforge/request/industrial_digital_in_4_v2_bricklet/XYZ/get_value

Callback

Download (example-callback.txt)

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# Change XYZ to the UID of your Industrial Digital In 4 Bricklet 2.0

setup:
    # Handle incoming value callbacks
    subscribe to tinkerforge/callback/industrial_digital_in_4_v2_bricklet/XYZ/value
    publish '{"register": true}' to tinkerforge/register/industrial_digital_in_4_v2_bricklet/XYZ/value # Register value callback
    
    # Set period for value (channel 1) callback to 0.1s (100ms)
    publish '{"channel": 1, "period": 100, "value_has_to_change": false}' to tinkerforge/request/industrial_digital_in_4_v2_bricklet/XYZ/set_value_callback_configuration

Edge Count

Download (example-edge-count.txt)

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# Change XYZ to the UID of your Industrial Digital In 4 Bricklet 2.0

setup:
    # Configure rising edge count (channel 3) with 10ms debounce
    publish '{"channel": "3", "edge_type": "rising", "debounce": 10}' to tinkerforge/request/industrial_digital_in_4_v2_bricklet/XYZ/set_edge_count_configuration 
    
    # Get edge count 10 times with 1s delay
    for i in 0 1 2 3 4 5 6 7 8 9; do
    
        wait for 1s 
    
        # Get current edge count
    subscribe to tinkerforge/response/industrial_digital_in_4_v2_bricklet/XYZ/get_edge_count
    publish '{"channel": "3", "reset_counter": false}' to tinkerforge/request/industrial_digital_in_4_v2_bricklet/XYZ/get_edge_count
    
    done

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 member _ERROR. It is published on the corresponding response topic: .../response/... for .../request/... and .../callback/... for .../register/....

Basic Functions

request/industrial_digital_in_4_v2_bricklet/<UID>/get_value
Request:
  • empty payload
Response:
  • value – Type: [bool, ...], Length: 4

Returns the input value as bools, true refers to high and false refers to low.

request/industrial_digital_in_4_v2_bricklet/<UID>/set_channel_led_config
Request:
  • channel – Type: int, Range: See symbols
  • config – Type: int, Range: See symbols
Response:
  • no response

Each channel has a corresponding LED. You can turn the LED off, on or show a heartbeat. You can also set the LED to "Channel Status". In this mode the LED is on if the channel is high and off otherwise.

By default all channel LEDs are configured as "Channel Status".

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3

For config:

  • "Off" = 0
  • "On" = 1
  • "ShowHeartbeat" = 2
  • "ShowChannelStatus" = 3
request/industrial_digital_in_4_v2_bricklet/<UID>/get_channel_led_config
Request:
  • channel – Type: int, Range: See symbols
Response:
  • config – Type: int, Range: See symbols

Returns the channel LED configuration as set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_channel_led_config

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3

For config:

  • "Off" = 0
  • "On" = 1
  • "ShowHeartbeat" = 2
  • "ShowChannelStatus" = 3

Advanced Functions

request/industrial_digital_in_4_v2_bricklet/<UID>/get_edge_count
Request:
  • channel – Type: int, Range: See symbols
  • reset_counter – Type: bool
Response:
  • count – Type: int, Range: [0 to 232 - 1]

Returns the current value of the edge counter for the selected channel. You can configure the edges that are counted with request/industrial_digital_in_4_v2_bricklet/<UID>/set_edge_count_configuration.

If you set the reset counter to true, the count is set back to 0 directly after it is read.

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3
request/industrial_digital_in_4_v2_bricklet/<UID>/set_edge_count_configuration
Request:
  • channel – Type: int, Range: See symbols
  • edge_type – Type: int, Range: See symbols
  • debounce – Type: int, Range: [0 to 255]
Response:
  • no response

Configures the edge counter for a specific channel.

The edge type parameter configures if rising edges, falling edges or both are counted. Possible edge types are:

  • 0 = rising (default)
  • 1 = falling
  • 2 = both

The debounce time is given in ms.

Configuring an edge counter resets its value to 0.

If you don't know what any of this means, just leave it at default. The default configuration is very likely OK for you.

Default values: 0 (edge type) and 100ms (debounce time)

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3

For edge_type:

  • "Rising" = 0
  • "Falling" = 1
  • "Both" = 2
request/industrial_digital_in_4_v2_bricklet/<UID>/get_edge_count_configuration
Request:
  • channel – Type: int, Range: See symbols
Response:
  • edge_type – Type: int, Range: See symbols
  • debounce – Type: int, Range: [0 to 255]

Returns the edge type and debounce time for the selected channel as set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_edge_count_configuration.

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3

For edge_type:

  • "Rising" = 0
  • "Falling" = 1
  • "Both" = 2
request/industrial_digital_in_4_v2_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/industrial_digital_in_4_v2_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
  • "BootloaderWaitForReboot" = 2
  • "FirmwareWaitForReboot" = 3
  • "FirmwareWaitForEraseAndReboot" = 4

For status:

  • "OK" = 0
  • "InvalidMode" = 1
  • "NoChange" = 2
  • "EntryFunctionNotPresent" = 3
  • "DeviceIdentifierIncorrect" = 4
  • "CRCMismatch" = 5
request/industrial_digital_in_4_v2_bricklet/<UID>/get_bootloader_mode
Request:
  • empty payload
Response:
  • mode – Type: int, Range: See symbols

Returns the current bootloader mode, see request/industrial_digital_in_4_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/industrial_digital_in_4_v2_bricklet/<UID>/set_write_firmware_pointer
Request:
  • pointer – Type: int, Range: [0 to 232 - 1]
Response:
  • no response

Sets the firmware pointer for request/industrial_digital_in_4_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/industrial_digital_in_4_v2_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/industrial_digital_in_4_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/industrial_digital_in_4_v2_bricklet/<UID>/set_status_led_config
Request:
  • config – Type: int, Range: See symbols
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
  • "ShowHeartbeat" = 2
  • "ShowStatus" = 3
request/industrial_digital_in_4_v2_bricklet/<UID>/get_status_led_config
Request:
  • empty payload
Response:
  • config – Type: int, Range: See symbols

Returns the configuration as set by request/industrial_digital_in_4_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/industrial_digital_in_4_v2_bricklet/<UID>/get_chip_temperature
Request:
  • empty payload
Response:
  • temperature – Type: int, Range: [-215 to 215 - 1]

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/industrial_digital_in_4_v2_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/industrial_digital_in_4_v2_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/industrial_digital_in_4_v2_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.

request/industrial_digital_in_4_v2_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
  • hardware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • firmware_version – Type: [int, ...], Length: 3, 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' 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 Industrial Digital In 4 2.0's name in a human readable form.

Callback Configuration Functions

request/industrial_digital_in_4_v2_bricklet/<UID>/set_value_callback_configuration
Request:
  • channel – Type: int, Range: See symbols
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
Response:
  • no response

This callback can be configured per channel.

The period is the period with which the register/industrial_digital_in_4_v2_bricklet/<UID>/value 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.

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3
request/industrial_digital_in_4_v2_bricklet/<UID>/get_value_callback_configuration
Request:
  • channel – Type: int, Range: See symbols
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false

Returns the callback configuration for the given channel as set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_value_callback_configuration.

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3
request/industrial_digital_in_4_v2_bricklet/<UID>/set_all_value_callback_configuration
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false
Response:
  • no response

The period is the period with which the register/industrial_digital_in_4_v2_bricklet/<UID>/all_value 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.

request/industrial_digital_in_4_v2_bricklet/<UID>/get_all_value_callback_configuration
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: false

Returns the callback configuration as set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_all_value_callback_configuration.

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/industrial_digital_in_4_v2_bricklet/<UID>/value
Register Request:
  • register – Type: bool
Callback Response:
  • channel – Type: int, Range: See symbols
  • changed – Type: bool
  • value – Type: bool

A callback can be registered for this event by publishing to the .../register/industrial_digital_in_4_v2_bricklet/<UID>/value[/<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/industrial_digital_in_4_v2_bricklet/<UID>/value[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically according to the configuration set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_value_callback_configuration.

The callback payload members are the channel, a value-changed indicator and the actual value for the channel. The changed parameter is true if the value has changed since the last callback.

The following symbols are available for this function:

For channel:

  • "0" = 0
  • "1" = 1
  • "2" = 2
  • "3" = 3
register/industrial_digital_in_4_v2_bricklet/<UID>/all_value
Register Request:
  • register – Type: bool
Callback Response:
  • changed – Type: [bool, ...], Length: 4
  • value – Type: [bool, ...], Length: 4

A callback can be registered for this event by publishing to the .../register/industrial_digital_in_4_v2_bricklet/<UID>/all_value[/<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/industrial_digital_in_4_v2_bricklet/<UID>/all_value[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically according to the configuration set by request/industrial_digital_in_4_v2_bricklet/<UID>/set_all_value_callback_configuration.

The callback payload members are the same as request/industrial_digital_in_4_v2_bricklet/<UID>/get_value. Additional the changed parameter is true if the value has changed since the last callback.