Shell - RS232 Bricklet 2.0

This is the description of the Shell API bindings for the RS232 Bricklet 2.0. General information and technical specifications for the RS232 Bricklet 2.0 are summarized in its hardware description.

An installation guide for the Shell API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Loopback

Download (example-loopback.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

# For this example connect the RX pin to the TX pin on the same Bricklet

uid=XYZ # Change XYZ to the UID of your RS232 Bricklet 2.0

# Handle incoming read callbacks
tinkerforge dispatch rs232-v2-bricklet $uid read &

# Enable read callback
tinkerforge call rs232-v2-bricklet $uid enable-read-callback

# Write "test" string
tinkerforge call rs232-v2-bricklet $uid write t,e,s,t

echo "Press key to exit"; read dummy

kill -- -$$ # Stop callback dispatch in background

API

Possible exit codes for all tinkerforge commands are:

  • 1: interrupted (ctrl+c)
  • 2: syntax error
  • 21: Python 2.5 or newer is required
  • 22: Python argparse module is missing
  • 23: socket error
  • 24: other exception
  • 25: invalid placeholder in format string
  • 26: authentication error
  • 201: timeout occurred
  • 209: invalid argument value
  • 210: function is not supported
  • 211: unknown error

Command Structure

The common options of the call and dispatch commands are documented here. The specific command structure is shown below.

tinkerforge call rs232-v2-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the RS232 Bricklet 2.0. It can take several options:

  • --help shows help for the specific call command and exits
  • --list-functions shows a list of known functions of the RS232 Bricklet 2.0 and exits
tinkerforge dispatch rs232-v2-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the RS232 Bricklet 2.0. It can take several options:

  • --help shows help for the specific dispatch command and exits
  • --list-callbacks shows a list of known callbacks of the RS232 Bricklet 2.0 and exits
tinkerforge call rs232-v2-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The <function> to be called can take different options depending of its kind. All functions can take the following options:

  • --help shows help for the specific function and exits

Getter functions can take the following options:

  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Setter functions can take the following options:

  • --expect-response requests response and waits for it

The --expect-response option for setter functions allows to detect timeouts and other error conditions calls of setters as well. The device will then send a response for this purpose. If this option is not given for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch rs232-v2-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> -- string
  • <callback> -- string

The <callback> to be dispatched can take several options:

  • --help shows help for the specific callback and exits
  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Basic Functions

tinkerforge call rs232-v2-bricklet <uid> write-low-level <message-length> <message-chunk-offset> <message-chunk-data>
Parameters:
  • <message-length> -- int
  • <message-chunk-offset> -- int
  • <message-chunk-data> -- char,char,..57x..,char
Output:
  • message-chunk-written -- int

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 set-configuration for configuration possibilities regarding baud rate, parity and so on.

tinkerforge call rs232-v2-bricklet <uid> read-low-level <length>
Parameters:
  • <length> -- int
Output:
  • message-length -- int
  • message-chunk-offset -- int
  • message-chunk-data -- char,char,..57x..,char

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 enable-read-callback and read callback.

tinkerforge call rs232-v2-bricklet <uid> set-configuration <baudrate> <parity> <stopbits> <wordlength> <flowcontrol>
Parameters:
  • <baudrate> -- int
  • <parity> -- int (has symbols)
  • <stopbits> -- int (has symbols)
  • <wordlength> -- int (has symbols)
  • <flowcontrol> -- int (has symbols)
Output:

no output

Sets the configuration for the RS232 communication. Available options:

  • Baud rate between 100 and 2000000 baud.
  • Parity of none, odd or even.
  • Stop bits can be 1 or 2.
  • Word length of 5 to 8.
  • Flow control can be off, software or hardware.

The default is: 115200 baud, parity none, 1 stop bit, word length 8.

The following symbols are available for this function:

  • parity-none = 0, for <parity>
  • parity-odd = 1, for <parity>
  • parity-even = 2, for <parity>
  • stopbits-1 = 1, for <stopbits>
  • stopbits-2 = 2, for <stopbits>
  • wordlength-5 = 5, for <wordlength>
  • wordlength-6 = 6, for <wordlength>
  • wordlength-7 = 7, for <wordlength>
  • wordlength-8 = 8, for <wordlength>
  • flowcontrol-off = 0, for <flowcontrol>
  • flowcontrol-software = 1, for <flowcontrol>
  • flowcontrol-hardware = 2, for <flowcontrol>
tinkerforge call rs232-v2-bricklet <uid> get-configuration
Output:
  • baudrate -- int
  • parity -- int (has symbols)
  • stopbits -- int (has symbols)
  • wordlength -- int (has symbols)
  • flowcontrol -- int (has symbols)

Returns the configuration as set by set-configuration.

The following symbols are available for this function:

  • parity-none = 0, for parity
  • parity-odd = 1, for parity
  • parity-even = 2, for parity
  • stopbits-1 = 1, for stopbits
  • stopbits-2 = 2, for stopbits
  • wordlength-5 = 5, for wordlength
  • wordlength-6 = 6, for wordlength
  • wordlength-7 = 7, for wordlength
  • wordlength-8 = 8, for wordlength
  • flowcontrol-off = 0, for flowcontrol
  • flowcontrol-software = 1, for flowcontrol
  • flowcontrol-hardware = 2, for flowcontrol

Advanced Functions

tinkerforge call rs232-v2-bricklet <uid> set-buffer-config <send-buffer-size> <receive-buffer-size>
Parameters:
  • <send-buffer-size> -- int
  • <receive-buffer-size> -- int
Output:

no output

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

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

The send buffer holds data that is given by 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 read or through read callback.

The default configuration is 5120 byte (5kb) per buffer.

tinkerforge call rs232-v2-bricklet <uid> get-buffer-config
Output:
  • send-buffer-size -- int
  • receive-buffer-size -- int

Returns the buffer configuration as set by set-buffer-config.

tinkerforge call rs232-v2-bricklet <uid> get-buffer-status
Output:
  • send-buffer-used -- int
  • receive-buffer-used -- int

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

See set-buffer-config for buffer size configuration.

tinkerforge call rs232-v2-bricklet <uid> get-error-count
Output:
  • error-count-overrun -- int
  • error-count-parity -- int

Returns the current number of overrun and parity errors.

tinkerforge call rs232-v2-bricklet <uid> get-spitfp-error-count
Output:
  • 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.

tinkerforge call rs232-v2-bricklet <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> -- int (has symbols)
Output:
  • 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:

  • bootloader-mode-bootloader = 0, for <mode>
  • bootloader-mode-firmware = 1, for <mode>
  • bootloader-mode-bootloader-wait-for-reboot = 2, for <mode>
  • bootloader-mode-firmware-wait-for-reboot = 3, for <mode>
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for <mode>
  • bootloader-status-ok = 0, for status
  • bootloader-status-invalid-mode = 1, for status
  • bootloader-status-no-change = 2, for status
  • bootloader-status-entry-function-not-present = 3, for status
  • bootloader-status-device-identifier-incorrect = 4, for status
  • bootloader-status-crc-mismatch = 5, for status
tinkerforge call rs232-v2-bricklet <uid> get-bootloader-mode
Output:
  • mode -- int (has symbols)

Returns the current bootloader mode, see set-bootloader-mode.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for mode
  • bootloader-mode-firmware = 1, for mode
  • bootloader-mode-bootloader-wait-for-reboot = 2, for mode
  • bootloader-mode-firmware-wait-for-reboot = 3, for mode
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for mode
tinkerforge call rs232-v2-bricklet <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> -- int
Output:

no output

Sets the firmware pointer for 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.

tinkerforge call rs232-v2-bricklet <uid> write-firmware <data>
Parameters:
  • <data> -- int,int,..61x..,int
Output:
  • status -- int

Writes 64 Bytes of firmware at the position as written by 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.

tinkerforge call rs232-v2-bricklet <uid> set-status-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

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:

  • status-led-config-off = 0, for <config>
  • status-led-config-on = 1, for <config>
  • status-led-config-show-heartbeat = 2, for <config>
  • status-led-config-show-status = 3, for <config>
tinkerforge call rs232-v2-bricklet <uid> get-status-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-status-led-config

The following symbols are available for this function:

  • status-led-config-off = 0, for config
  • status-led-config-on = 1, for config
  • status-led-config-show-heartbeat = 2, for config
  • status-led-config-show-status = 3, for config
tinkerforge call rs232-v2-bricklet <uid> get-chip-temperature
Output:
  • 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.

tinkerforge call rs232-v2-bricklet <uid> reset
Output:no output

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!

tinkerforge call rs232-v2-bricklet <uid> write-uid <uid>
Parameters:
  • <uid> -- int
Output:

no output

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.

tinkerforge call rs232-v2-bricklet <uid> read-uid
Output:
  • uid -- int

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

tinkerforge call rs232-v2-bricklet <uid> get-identity
Output:
  • uid -- string
  • connected-uid -- string
  • position -- char
  • hardware-version -- int,int,int
  • firmware-version -- int,int,int
  • device-identifier -- int (has symbols)

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

Callback Configuration Functions

tinkerforge call rs232-v2-bricklet <uid> enable-read-callback
Output:no output

Enables the read callback.

By default the callback is disabled.

tinkerforge call rs232-v2-bricklet <uid> disable-read-callback
Output:no output

Disables the read callback.

By default the callback is disabled.

tinkerforge call rs232-v2-bricklet <uid> is-read-callback-enabled
Output:
  • enabled -- bool

Returns true if the read callback is enabled, false otherwise.

Callbacks

Callbacks can be used to receive time critical or recurring data from the device:

tinkerforge dispatch rs232-v2-bricklet <uid> example

The available callbacks are described below.

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.

tinkerforge dispatch rs232-v2-bricklet <uid> read-low-level
Output:
  • message-length -- int
  • message-chunk-offset -- int
  • message-chunk-data -- char,char,..57x..,char

This callback is called if new data is available.

To enable this callback, use enable-read-callback.

tinkerforge dispatch rs232-v2-bricklet <uid> error-count
Output:
  • error-count-overrun -- int
  • error-count-parity -- int

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