MQTT - RS232 Bricklet 2.0¶

Loopback¶

Download (example-loopback.txt)

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# For this example connect the RX1 and TX pin to receive the send message

# Change XYZ to the UID of your RS232 Bricklet 2.0

setup:
    # Handle incoming read callbacks
    subscribe to tinkerforge/callback/rs232_v2_bricklet/XYZ/read # Received messages contain the message as string
    publish '{"register": true}' to tinkerforge/register/rs232_v2_bricklet/XYZ/read # Register read callback

    # Enable read callback
    publish '' to tinkerforge/request/rs232_v2_bricklet/XYZ/enable_read_callback

    # Write "test" string
    publish '{"message": "test"}' to tinkerforge/request/rs232_v2_bricklet/XYZ/write

Basic Functions¶

request/rs232_v2_bricklet/<UID>/write¶

Request:	message – Type: [char, ...], Length: variable
Response:	message_written – Type: int, Range: [0 to 216 - 1]

Writes characters to the RS232 interface. The characters can be binary data, ASCII or similar is not necessary.

The return value is the number of characters that were written.

See request/rs232_v2_bricklet/<UID>/set_configuration for configuration possibilities regarding baud rate, parity and so on.

request/rs232_v2_bricklet/<UID>/read¶

Request:	length – Type: int, Range: [0 to 216 - 1]
Response:	message – Type: [char, ...], Length: variable

Returns up to length characters from receive buffer.

Instead of polling with this function, you can also use callbacks. But note that this function will return available data only when the read callback is disabled. See request/rs232_v2_bricklet/<UID>/enable_read_callback and register/rs232_v2_bricklet/<UID>/read callback.

request/rs232_v2_bricklet/<UID>/set_configuration¶

Request:	baudrate – Type: int, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 parity – Type: int, Range: See symbols, Default: 0 stopbits – Type: int, Range: See symbols, Default: 1 wordlength – Type: int, Range: See symbols, Default: 8 flowcontrol – Type: int, Range: See symbols, Default: 0
Response:	no response

Sets the configuration for the RS232 communication.

The following symbols are available for this function:

For parity:

• "none" = 0
• "odd" = 1
• "even" = 2

For stopbits:

• "1" = 1
• "2" = 2

For wordlength:

• "5" = 5
• "6" = 6
• "7" = 7
• "8" = 8

For flowcontrol:

• "off" = 0
• "software" = 1
• "hardware" = 2

request/rs232_v2_bricklet/<UID>/get_configuration¶

Request:	empty payload
Response:	baudrate – Type: int, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 parity – Type: int, Range: See symbols, Default: 0 stopbits – Type: int, Range: See symbols, Default: 1 wordlength – Type: int, Range: See symbols, Default: 8 flowcontrol – Type: int, Range: See symbols, Default: 0

Returns the configuration as set by request/rs232_v2_bricklet/<UID>/set_configuration.

The following symbols are available for this function:

For parity:

• "none" = 0
• "odd" = 1
• "even" = 2

For stopbits:

• "1" = 1
• "2" = 2

For wordlength:

• "5" = 5
• "6" = 6
• "7" = 7
• "8" = 8

For flowcontrol:

• "off" = 0
• "software" = 1
• "hardware" = 2

Advanced Functions¶

request/rs232_v2_bricklet/<UID>/set_buffer_config¶

Request:	send_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120 receive_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120
Response:	no response

Sets the send and receive buffer size in byte. In total the buffers have to be 10240 byte (10KiB) in size, the minimum buffer size is 1024 byte (1KiB) for each.

The current buffer content is lost if this function is called.

The send buffer holds data that is given by request/rs232_v2_bricklet/<UID>/write and can not be written yet. The receive buffer holds data that is received through RS232 but could not yet be send to the user, either by request/rs232_v2_bricklet/<UID>/read or through register/rs232_v2_bricklet/<UID>/read callback.

request/rs232_v2_bricklet/<UID>/get_buffer_config¶

Request:	empty payload
Response:	send_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120 receive_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120

Returns the buffer configuration as set by request/rs232_v2_bricklet/<UID>/set_buffer_config.

request/rs232_v2_bricklet/<UID>/get_buffer_status¶

Request:	empty payload
Response:	send_buffer_used – Type: int, Unit: 1 B, Range: [0 to 9216] receive_buffer_used – Type: int, Unit: 1 B, Range: [0 to 9216]

Returns the currently used bytes for the send and received buffer.

See request/rs232_v2_bricklet/<UID>/set_buffer_config for buffer size configuration.

request/rs232_v2_bricklet/<UID>/get_error_count¶

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

Returns the current number of overrun and parity errors.

request/rs232_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/rs232_v2_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/rs232_v2_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/rs232_v2_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/rs232_v2_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/rs232_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/rs232_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, 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 RS232 2.0's name in a human readable form.

Callback Configuration Functions¶

request/rs232_v2_bricklet/<UID>/enable_read_callback¶

Request:	empty payload
Response:	no response

Enables the register/rs232_v2_bricklet/<UID>/read callback. This will disable the register/rs232_v2_bricklet/<UID>/frame_readable callback.

By default the callback is disabled.

request/rs232_v2_bricklet/<UID>/disable_read_callback¶

Request:	empty payload
Response:	no response

Disables the register/rs232_v2_bricklet/<UID>/read callback.

By default the callback is disabled.

request/rs232_v2_bricklet/<UID>/is_read_callback_enabled¶

Request:	empty payload
Response:	enabled – Type: bool, Default: false

Returns true if the register/rs232_v2_bricklet/<UID>/read callback is enabled, false otherwise.

request/rs232_v2_bricklet/<UID>/set_frame_readable_callback_configuration¶

Request:	frame_size – Type: int, Unit: 1 B, Range: [0 to 9216], Default: 0
Response:	no response

Configures the register/rs232_v2_bricklet/<UID>/frame_readable callback. The frame size is the number of bytes, that have to be readable to trigger the callback. A frame size of 0 disables the callback. A frame size greater than 0 enables the callback and disables the register/rs232_v2_bricklet/<UID>/read callback.

By default the callback is disabled.

New in version 2.0.3 (Plugin).

request/rs232_v2_bricklet/<UID>/get_frame_readable_callback_configuration¶

Request:	empty payload
Response:	frame_size – Type: int, Unit: 1 B, Range: [0 to 9216], Default: 0

Returns the callback configuration as set by request/rs232_v2_bricklet/<UID>/set_frame_readable_callback_configuration.

New in version 2.0.3 (Plugin).

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/rs232_v2_bricklet/<UID>/read¶

Register Request:	register – Type: bool
Callback Response:	message – Type: [char, ...], Length: variable

A callback can be registered for this event by publishing to the .../register/rs232_v2_bricklet/<UID>/read[/<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/rs232_v2_bricklet/<UID>/read[/<SUFFIX>] topic for each registered suffix.

This callback is called if new data is available.

To enable this callback, use request/rs232_v2_bricklet/<UID>/enable_read_callback.

Note

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

register/rs232_v2_bricklet/<UID>/error_count¶

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

A callback can be registered for this event by publishing to the .../register/rs232_v2_bricklet/<UID>/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/rs232_v2_bricklet/<UID>/error_count[/<SUFFIX>] topic for each registered suffix.

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

register/rs232_v2_bricklet/<UID>/frame_readable¶

Register Request:	register – Type: bool
Callback Response:	frame_count – Type: int, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs232_v2_bricklet/<UID>/frame_readable[/<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/rs232_v2_bricklet/<UID>/frame_readable[/<SUFFIX>] topic for each registered suffix.

This callback is called if at least one frame of data is readable. The frame size is configured with request/rs232_v2_bricklet/<UID>/set_frame_readable_callback_configuration. The frame count parameter is the number of frames that can be read. This callback is triggered only once until request/rs232_v2_bricklet/<UID>/read is called. This means, that if you have configured a frame size of X bytes, you can read exactly X bytes using the request/rs232_v2_bricklet/<UID>/read function, every time the callback triggers without checking the frame count callback payload.

New in version 2.0.3 (Plugin).

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/rs232_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
• "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/rs232_v2_bricklet/<UID>/get_bootloader_mode¶

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

Returns the current bootloader mode, see request/rs232_v2_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/rs232_v2_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/rs232_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/rs232_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/rs232_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/rs232_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/rs232_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.