Shell - Joystick Bricklet 2.0

This is the description of the Shell API bindings for the Joystick Bricklet 2.0. General information and technical specifications for the Joystick 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).

Simple

Download (example-simple.sh)

1
2
3
4
5
6
7
#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

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

# Get current position
tinkerforge call joystick-v2-bricklet $uid get-position

Callback

Download (example-callback.sh)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

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

# Handle incoming pressed callbacks
tinkerforge dispatch joystick-v2-bricklet $uid pressed &

# Set period for pressed callback to 0.01s (10ms)
tinkerforge call joystick-v2-bricklet $uid set-pressed-callback-configuration 10 true

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

The call command is used to call a function of the Joystick 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 Joystick Bricklet 2.0 and exits
tinkerforge dispatch joystick-v2-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the Joystick 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 Joystick Bricklet 2.0 and exits
tinkerforge call joystick-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 joystick-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 joystick-v2-bricklet <uid> get-position
Output:
  • x -- int
  • y -- int

Returns the position of the joystick. The value ranges between -100 and 100 for both axis. The middle position of the joystick is x=0, y=0. The returned values are averaged and calibrated (see calibrate).

If you want to get the position periodically, it is recommended to use the position callback and set the period with set-position-callback-configuration.

tinkerforge call joystick-v2-bricklet <uid> is-pressed
Output:
  • pressed -- bool

Returns true if the button is pressed and false otherwise.

If you want to get the press-state periodically, it is recommended to use the pressed callback and set the period with set-pressed-callback-configuration.

Advanced Functions

tinkerforge call joystick-v2-bricklet <uid> calibrate
Output:no output

Calibrates the middle position of the joystick. If your Joystick Bricklet 2.0 does not return x=0 and y=0 in the middle position, call this function while the joystick is standing still in the middle position.

The resulting calibration will be saved in non-volatile memory, thus you only have to calibrate it once.

tinkerforge call joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-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 joystick-v2-bricklet <uid> set-position-callback-configuration <period> <value-has-to-change>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
Output:

no output

The period in ms is the period with which the position 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 at least one of the values has changed. If the values 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 default value is (0, false).

tinkerforge call joystick-v2-bricklet <uid> get-position-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool

Returns the callback configuration as set by set-position-callback-configuration.

tinkerforge call joystick-v2-bricklet <uid> set-pressed-callback-configuration <period> <value-has-to-change>
Parameters:
  • <period> -- int
  • <value-has-to-change> -- bool
Output:

no output

The period in ms is the period with which the pressed 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 at least one of the values has changed. If the values 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 default value is (0, false).

tinkerforge call joystick-v2-bricklet <uid> get-pressed-callback-configuration
Output:
  • period -- int
  • value-has-to-change -- bool

Returns the callback configuration as set by set-pressed-callback-configuration.

Callbacks

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

tinkerforge dispatch joystick-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 joystick-v2-bricklet <uid> position
Output:
  • x -- int
  • y -- int

This callback is triggered periodically according to the configuration set by set-position-callback-configuration.

The parameters are the same as with get-position.

tinkerforge dispatch joystick-v2-bricklet <uid> pressed
Output:
  • pressed -- bool

This callback is triggered periodically according to the configuration set by set-pressed-callback-configuration.

The parameters are the same as with is-pressed.