Shell - LED Strip Bricklet

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

# Set first 10 LEDs to green
tinkerforge call led-strip-bricklet $uid set-rgb-values 0 10 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 255,255,255,255,255,255,255,255,255,255,0,0,0,0,0,0 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0

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

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

The dispatch command is used to dispatch a callback of the LED Strip Bricklet. 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 and exits
tinkerforge call led-strip-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-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-bricklet <uid> set-rgb-values <index> <length> <r> <g> <b>
Parameters:
  • <index> -- int
  • <length> -- int
  • <r> -- int,int,..13x..,int
  • <g> -- int,int,..13x..,int
  • <b> -- int,int,..13x..,int
Output:

no output

Sets the RGB values for the LEDs with the given length starting from index.

To make the colors show correctly you need to configure the chip type (set-chip-type) and a 3-channel channel mapping (set-channel-mapping) according to the connected LEDs.

The maximum length is 16, the index goes from 0 to 319 and the rgb values have 8 bits each.

Example: If you set

  • index to 5,
  • length to 3,
  • r to [255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  • g to [0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] and
  • b to [0, 0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

the LED with index 5 will be red, 6 will be green and 7 will be blue.

Note

Depending on the LED circuitry colors can be permuted.

The colors will be transfered to actual 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-rendered callback.
  • Set all of the LED colors for next frame.
  • Wait for the frame-rendered callback.
  • and so on.

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

The actual number of controllable LEDs depends on the number of free Bricklet ports. See here for more information. A call of set-rgb-values with index + length above the bounds is ignored completely.

tinkerforge call led-strip-bricklet <uid> get-rgb-values <index> <length>
Parameters:
  • <index> -- int
  • <length> -- int
Output:
  • r -- int,int,..13x..,int
  • g -- int,int,..13x..,int
  • b -- int,int,..13x..,int

Returns RGB value with the given length starting from the given index.

The values are the last values that were set by set-rgb-values.

tinkerforge call led-strip-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-rgb-values.

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

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

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

tinkerforge call led-strip-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-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.

Note

The frequency in firmware version 2.0.0 is fixed at 2MHz.

New in version 2.0.1 (Plugin).

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

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

New in version 2.0.1 (Plugin).

tinkerforge call led-strip-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>

New in version 2.0.2 (Plugin).

tinkerforge call led-strip-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

New in version 2.0.2 (Plugin).

tinkerforge call led-strip-bricklet <uid> set-rgbw-values <index> <length> <r> <g> <b> <w>
Parameters:
  • <index> -- int
  • <length> -- int
  • <r> -- int,int,..9x..,int
  • <g> -- int,int,..9x..,int
  • <b> -- int,int,..9x..,int
  • <w> -- int,int,..9x..,int
Output:

no output

Sets the RGBW values for the LEDs with the given length starting from index.

To make the colors show correctly you need to configure the chip type (set-chip-type) and a 4-channel channel mapping (set-channel-mapping) according to the connected LEDs.

The maximum length is 12, the index goes from 0 to 239 and the rgbw values have 8 bits each.

Example: If you set

  • index to 5,
  • length to 4,
  • r to [255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  • g to [0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  • b to [0, 0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0] and
  • w to [0, 0, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0]

the LED with index 5 will be red, 6 will be green, 7 will be blue and 8 will be white.

Note

Depending on the LED circuitry colors can be permuted.

The colors will be transfered to actual 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-rendered callback.
  • Set all of the LED colors for next frame.
  • Wait for the frame-rendered callback.
  • and so on.

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

The actual number of controllable LEDs depends on the number of free Bricklet ports. See here for more information. A call of set-rgbw-values with index + length above the bounds is ignored completely.

The LPD8806 LED driver chips have 7-bit channels for RGB. Internally the LED Strip Bricklets divides the 8-bit values set using this function by 2 to make them 7-bit. Therefore, you can just use the normal value range (0-255) for LPD8806 LEDs.

The brightness channel of the APA102 LED driver chips has 5-bit. Internally the LED Strip Bricklets divides the 8-bit values set using this function by 8 to make them 5-bit. Therefore, you can just use the normal value range (0-255) for the brightness channel of APA102 LEDs.

New in version 2.0.6 (Plugin).

tinkerforge call led-strip-bricklet <uid> get-rgbw-values <index> <length>
Parameters:
  • <index> -- int
  • <length> -- int
Output:
  • r -- int,int,..9x..,int
  • g -- int,int,..9x..,int
  • b -- int,int,..9x..,int
  • w -- int,int,..9x..,int

Returns RGBW values with the given length starting from the given index.

The values are the last values that were set by set-rgbw-values.

New in version 2.0.6 (Plugin).

tinkerforge call led-strip-bricklet <uid> set-channel-mapping <mapping>
Parameters:
  • <mapping> -- int (has symbols)
Output:

no output

Sets the channel mapping for the connected LEDs.

set-rgb-values and set-rgbw-values take the data in RGB(W) order. But 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, the 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.

If a 3-channel mapping is selected then set-rgb-values has to be used. Calling set-rgbw-values with a 3-channel mapping will produce incorrect results. Vice-versa if a 4-channel mapping is selected then set-rgbw-values has to be used. Calling set-rgb-values with a 4-channel mapping will produce incorrect results.

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>

New in version 2.0.6 (Plugin).

tinkerforge call led-strip-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

New in version 2.0.6 (Plugin).

Advanced Functions

tinkerforge call led-strip-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-bricklet <uid> enable-frame-rendered-callback
Output:no output

Enables the frame-rendered callback.

By default the callback is enabled.

New in version 2.0.6 (Plugin).

tinkerforge call led-strip-bricklet <uid> disable-frame-rendered-callback
Output:no output

Disables the frame-rendered callback.

By default the callback is enabled.

New in version 2.0.6 (Plugin).

tinkerforge call led-strip-bricklet <uid> is-frame-rendered-callback-enabled
Output:
  • enabled -- bool

Returns true if the frame-rendered callback is enabled, false otherwise.

New in version 2.0.6 (Plugin).

Callbacks

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

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

This callback is triggered directly after a new frame is rendered. 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-rgb-values.