Shell - LED Strip Bricklet 2.0

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

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

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

# Set first 3 LEDs to red, green and blue
tinkerforge call led-strip-v2-bricklet $uid set-led-values 0 255,0,0,0,255,0,0,0,255

Callback

Download (example-callback.sh)

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

# FIXME: This example is incomplete

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

# Set frame duration to 50ms (20 frames per second)
tinkerforge call led-strip-v2-bricklet $uid set-frame-duration 50

# Use frame started callback to move the active LED every frame
tinkerforge dispatch led-strip-v2-bricklet $uid frame-started &

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

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

The dispatch command is used to dispatch a callback of the LED Strip 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 LED Strip Bricklet 2.0 and exits
tinkerforge call led-strip-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 led-strip-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 led-strip-v2-bricklet <uid> set-led-values-low-level <index> <value-length> <value-chunk-offset> <value-chunk-data>
Parameters:
  • <index> -- int
  • <value-length> -- int
  • <value-chunk-offset> -- int
  • <value-chunk-data> -- int,int,..55x..,int
Output:

no output

Sets the RGB(W) values for the LEDs starting from index. You can set at most 2048 RGB values or 1536 RGBW values.

To make the colors show correctly you need to configure the chip type (see set-chip-type) and a channel mapping (see set-channel-mapping) according to the connected LEDs.

If the channel mapping has 3 colors, you need to give the data in the sequence RGBRGBRGB... if the channel mapping has 4 colors you need to give data in the sequence RGBWRGBWRGBW...

The data is double buffered and the colors will be transfered to the LEDs when the next frame duration ends (see set-frame-duration).

Generic approach:

  • Set the frame duration to a value that represents the number of frames per second you want to achieve.
  • Set all of the LED colors for one frame.
  • Wait for the frame-started callback.
  • Set all of the LED colors for next frame.
  • Wait for the frame-started callback.
  • And so on.

This approach ensures that you can change the LED colors with a fixed frame rate.

tinkerforge call led-strip-v2-bricklet <uid> get-led-values-low-level <index> <length>
Parameters:
  • <index> -- int
  • <length> -- int
Output:
  • value-length -- int
  • value-chunk-offset -- int
  • value-chunk-data -- int,int,..57x..,int

Returns the RGB(W) values as set by set-led-values.

tinkerforge call led-strip-v2-bricklet <uid> set-frame-duration <duration>
Parameters:
  • <duration> -- int
Output:

no output

Sets the frame duration in ms.

Example: If you want to achieve 20 frames per second, you should set the frame duration to 50ms (50ms * 20 = 1 second).

For an explanation of the general approach see set-led-values.

Default value: 100ms (10 frames per second).

tinkerforge call led-strip-v2-bricklet <uid> get-frame-duration
Output:
  • duration -- int

Returns the frame duration in ms as set by set-frame-duration.

tinkerforge call led-strip-v2-bricklet <uid> get-supply-voltage
Output:
  • voltage -- int

Returns the current supply voltage of the LEDs. The voltage is given in mV.

tinkerforge call led-strip-v2-bricklet <uid> set-clock-frequency <frequency>
Parameters:
  • <frequency> -- int
Output:

no output

Sets the frequency of the clock in Hz. The range is 10000Hz (10kHz) up to 2000000Hz (2MHz).

The Bricklet will choose the nearest achievable frequency, which may be off by a few Hz. You can get the exact frequency that is used by calling get-clock-frequency.

If you have problems with flickering LEDs, they may be bits flipping. You can fix this by either making the connection between the LEDs and the Bricklet shorter or by reducing the frequency.

With a decreasing frequency your maximum frames per second will decrease too.

The default value is 1.66MHz.

tinkerforge call led-strip-v2-bricklet <uid> get-clock-frequency
Output:
  • frequency -- int

Returns the currently used clock frequency as set by set-clock-frequency.

tinkerforge call led-strip-v2-bricklet <uid> set-chip-type <chip>
Parameters:
  • <chip> -- int (has symbols)
Output:

no output

Sets the type of the LED driver chip. We currently support the chips

  • WS2801,
  • WS2811,
  • WS2812 / SK6812 / NeoPixel RGB,
  • SK6812RGBW / NeoPixel RGBW (Chip Type = WS2812),
  • LPD8806 and
  • APA102 / DotStar.

The default value is WS2801 (2801).

The following symbols are available for this function:

  • chip-type-ws2801 = 2801, for <chip>
  • chip-type-ws2811 = 2811, for <chip>
  • chip-type-ws2812 = 2812, for <chip>
  • chip-type-lpd8806 = 8806, for <chip>
  • chip-type-apa102 = 102, for <chip>
tinkerforge call led-strip-v2-bricklet <uid> get-chip-type
Output:
  • chip -- int (has symbols)

Returns the currently used chip type as set by set-chip-type.

The following symbols are available for this function:

  • chip-type-ws2801 = 2801, for chip
  • chip-type-ws2811 = 2811, for chip
  • chip-type-ws2812 = 2812, for chip
  • chip-type-lpd8806 = 8806, for chip
  • chip-type-apa102 = 102, for chip
tinkerforge call led-strip-v2-bricklet <uid> set-channel-mapping <mapping>
Parameters:
  • <mapping> -- int (has symbols)
Output:

no output

Sets the channel mapping for the connected LEDs.

If the mapping has 4 colors, the function set-led-values expects 4 values per pixel and if the mapping has 3 colors it expects 3 values per pixel.

The function always expects the order RGB(W). The connected LED driver chips might have their 3 or 4 channels in a different order. For example, the WS2801 chips typically use BGR order, then WS2812 chips typically use GRB order and the APA102 chips typically use WBGR order.

The APA102 chips are special. They have three 8-bit channels for RGB and an additional 5-bit channel for the overall brightness of the RGB LED making them 4-channel chips. Internally the brightness channel is the first channel, therefore one of the Wxyz channel mappings should be used. Then the W channel controls the brightness.

The default value is BGR (36).

The following symbols are available for this function:

  • channel-mapping-rgb = 6, for <mapping>
  • channel-mapping-rbg = 9, for <mapping>
  • channel-mapping-brg = 33, for <mapping>
  • channel-mapping-bgr = 36, for <mapping>
  • channel-mapping-grb = 18, for <mapping>
  • channel-mapping-gbr = 24, for <mapping>
  • channel-mapping-rgbw = 27, for <mapping>
  • channel-mapping-rgwb = 30, for <mapping>
  • channel-mapping-rbgw = 39, for <mapping>
  • channel-mapping-rbwg = 45, for <mapping>
  • channel-mapping-rwgb = 54, for <mapping>
  • channel-mapping-rwbg = 57, for <mapping>
  • channel-mapping-grwb = 78, for <mapping>
  • channel-mapping-grbw = 75, for <mapping>
  • channel-mapping-gbwr = 108, for <mapping>
  • channel-mapping-gbrw = 99, for <mapping>
  • channel-mapping-gwbr = 120, for <mapping>
  • channel-mapping-gwrb = 114, for <mapping>
  • channel-mapping-brgw = 135, for <mapping>
  • channel-mapping-brwg = 141, for <mapping>
  • channel-mapping-bgrw = 147, for <mapping>
  • channel-mapping-bgwr = 156, for <mapping>
  • channel-mapping-bwrg = 177, for <mapping>
  • channel-mapping-bwgr = 180, for <mapping>
  • channel-mapping-wrbg = 201, for <mapping>
  • channel-mapping-wrgb = 198, for <mapping>
  • channel-mapping-wgbr = 216, for <mapping>
  • channel-mapping-wgrb = 210, for <mapping>
  • channel-mapping-wbgr = 228, for <mapping>
  • channel-mapping-wbrg = 225, for <mapping>
tinkerforge call led-strip-v2-bricklet <uid> get-channel-mapping
Output:
  • mapping -- int (has symbols)

Returns the currently used channel mapping as set by set-channel-mapping.

The following symbols are available for this function:

  • channel-mapping-rgb = 6, for mapping
  • channel-mapping-rbg = 9, for mapping
  • channel-mapping-brg = 33, for mapping
  • channel-mapping-bgr = 36, for mapping
  • channel-mapping-grb = 18, for mapping
  • channel-mapping-gbr = 24, for mapping
  • channel-mapping-rgbw = 27, for mapping
  • channel-mapping-rgwb = 30, for mapping
  • channel-mapping-rbgw = 39, for mapping
  • channel-mapping-rbwg = 45, for mapping
  • channel-mapping-rwgb = 54, for mapping
  • channel-mapping-rwbg = 57, for mapping
  • channel-mapping-grwb = 78, for mapping
  • channel-mapping-grbw = 75, for mapping
  • channel-mapping-gbwr = 108, for mapping
  • channel-mapping-gbrw = 99, for mapping
  • channel-mapping-gwbr = 120, for mapping
  • channel-mapping-gwrb = 114, for mapping
  • channel-mapping-brgw = 135, for mapping
  • channel-mapping-brwg = 141, for mapping
  • channel-mapping-bgrw = 147, for mapping
  • channel-mapping-bgwr = 156, for mapping
  • channel-mapping-bwrg = 177, for mapping
  • channel-mapping-bwgr = 180, for mapping
  • channel-mapping-wrbg = 201, for mapping
  • channel-mapping-wrgb = 198, for mapping
  • channel-mapping-wgbr = 216, for mapping
  • channel-mapping-wgrb = 210, for mapping
  • channel-mapping-wbgr = 228, for mapping
  • channel-mapping-wbrg = 225, for mapping

Advanced Functions

tinkerforge call led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-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 led-strip-v2-bricklet <uid> set-frame-started-callback-configuration <enable>
Parameters:
  • <enable> -- bool
Output:

no output

Enables/disables the frame-started callback.

By default the callback is enabled.

tinkerforge call led-strip-v2-bricklet <uid> get-frame-started-callback-configuration
Output:
  • enable -- bool

Returns the configuration as set by set-frame-started-callback-configuration.

Callbacks

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

tinkerforge dispatch led-strip-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 led-strip-v2-bricklet <uid> frame-started
Output:
  • length -- int

This callback is triggered directly after a new frame render is started. The parameter is the number of LEDs in that frame.

You should send the data for the next frame directly after this callback was triggered.

For an explanation of the general approach see set-led-values.