C/C++ - LED Strip Bricklet 2.0

This is the description of the C/C++ 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 C/C++ API bindings is part of their general description.

Examples

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

Simple

Download (example_simple.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_led_strip_v2.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your LED Strip Bricklet 2.0

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    LEDStripV2 ls;
    led_strip_v2_create(&ls, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Set first 3 LEDs to red, green and blue
    led_strip_v2_set_led_values(&ls, 0, (uint8_t[]){255, 0, 0, 0, 255, 0, 0, 0, 255}, 9);

    printf("Press key to exit\n");
    getchar();
    led_strip_v2_destroy(&ls);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Callback

Download (example_callback.c)

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#include <stdio.h>

// FIXME: This example is incomplete

#include "ip_connection.h"
#include "bricklet_led_strip_v2.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your LED Strip Bricklet 2.0

// Use frame started callback to move the active LED every frame
void cb_frame_started(uint16_t length, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Length: %u\n", length);
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    LEDStripV2 ls;
    led_strip_v2_create(&ls, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Set frame duration to 50ms (20 frames per second)
    led_strip_v2_set_frame_duration(&ls, 50);

    // Register frame started callback to function cb_frame_started
    led_strip_v2_register_callback(&ls,
                                   LED_STRIP_V2_CALLBACK_FRAME_STARTED,
                                   (void *)cb_frame_started,
                                   NULL);

    printf("Press key to exit\n");
    getchar();
    led_strip_v2_destroy(&ls);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

API

Every function of the C/C++ bindings returns an integer which describes an error code. Data returned from the device, when a getter is called, is handled via call by reference. These parameters are labeled with the ret_ prefix.

Possible error codes are:

  • E_OK = 0
  • E_TIMEOUT = -1
  • E_NO_STREAM_SOCKET = -2
  • E_HOSTNAME_INVALID = -3
  • E_NO_CONNECT = -4
  • E_NO_THREAD = -5
  • E_NOT_ADDED = -6 (unused since bindings version 2.0.0)
  • E_ALREADY_CONNECTED = -7
  • E_NOT_CONNECTED = -8
  • E_INVALID_PARAMETER = -9
  • E_NOT_SUPPORTED = -10
  • E_UNKNOWN_ERROR_CODE = -11
  • E_STREAM_OUT_OF_SYNC = -12

as defined in ip_connection.h.

All functions listed below are thread-safe.

Basic Functions

void led_strip_v2_create(LEDStripV2 *led_strip_v2, const char *uid, IPConnection *ipcon)

Creates the device object led_strip_v2 with the unique device ID uid and adds it to the IPConnection ipcon:

LEDStripV2 led_strip_v2;
led_strip_v2_create(&led_strip_v2, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected (see examples above).

void led_strip_v2_destroy(LEDStripV2 *led_strip_v2)

Removes the device object led_strip_v2 from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int led_strip_v2_set_led_values(LEDStripV2 *led_strip_v2, uint16_t index, uint8_t *value, uint16_t value_length)

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 led_strip_v2_set_chip_type()) and a channel mapping (see led_strip_v2_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 led_strip_v2_set_frame_duration()).

Generic approach:

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

int led_strip_v2_get_led_values(LEDStripV2 *led_strip_v2, uint16_t index, uint16_t length, uint8_t *ret_value, uint16_t *ret_value_length)

Returns the RGB(W) values as set by led_strip_v2_set_led_values().

int led_strip_v2_set_frame_duration(LEDStripV2 *led_strip_v2, uint16_t duration)

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 led_strip_v2_set_led_values().

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

int led_strip_v2_get_frame_duration(LEDStripV2 *led_strip_v2, uint16_t *ret_duration)

Returns the frame duration in ms as set by led_strip_v2_set_frame_duration().

int led_strip_v2_get_supply_voltage(LEDStripV2 *led_strip_v2, uint16_t *ret_voltage)

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

int led_strip_v2_set_clock_frequency(LEDStripV2 *led_strip_v2, uint32_t frequency)

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 led_strip_v2_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.

int led_strip_v2_get_clock_frequency(LEDStripV2 *led_strip_v2, uint32_t *ret_frequency)

Returns the currently used clock frequency as set by led_strip_v2_set_clock_frequency().

int led_strip_v2_set_chip_type(LEDStripV2 *led_strip_v2, uint16_t chip)

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 defines are available for this function:

  • LED_STRIP_V2_CHIP_TYPE_WS2801 = 2801
  • LED_STRIP_V2_CHIP_TYPE_WS2811 = 2811
  • LED_STRIP_V2_CHIP_TYPE_WS2812 = 2812
  • LED_STRIP_V2_CHIP_TYPE_LPD8806 = 8806
  • LED_STRIP_V2_CHIP_TYPE_APA102 = 102
int led_strip_v2_get_chip_type(LEDStripV2 *led_strip_v2, uint16_t *ret_chip)

Returns the currently used chip type as set by led_strip_v2_set_chip_type().

The following defines are available for this function:

  • LED_STRIP_V2_CHIP_TYPE_WS2801 = 2801
  • LED_STRIP_V2_CHIP_TYPE_WS2811 = 2811
  • LED_STRIP_V2_CHIP_TYPE_WS2812 = 2812
  • LED_STRIP_V2_CHIP_TYPE_LPD8806 = 8806
  • LED_STRIP_V2_CHIP_TYPE_APA102 = 102
int led_strip_v2_set_channel_mapping(LEDStripV2 *led_strip_v2, uint8_t mapping)

Sets the channel mapping for the connected LEDs.

If the mapping has 4 colors, the function led_strip_v2_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 defines are available for this function:

  • LED_STRIP_V2_CHANNEL_MAPPING_RGB = 6
  • LED_STRIP_V2_CHANNEL_MAPPING_RBG = 9
  • LED_STRIP_V2_CHANNEL_MAPPING_BRG = 33
  • LED_STRIP_V2_CHANNEL_MAPPING_BGR = 36
  • LED_STRIP_V2_CHANNEL_MAPPING_GRB = 18
  • LED_STRIP_V2_CHANNEL_MAPPING_GBR = 24
  • LED_STRIP_V2_CHANNEL_MAPPING_RGBW = 27
  • LED_STRIP_V2_CHANNEL_MAPPING_RGWB = 30
  • LED_STRIP_V2_CHANNEL_MAPPING_RBGW = 39
  • LED_STRIP_V2_CHANNEL_MAPPING_RBWG = 45
  • LED_STRIP_V2_CHANNEL_MAPPING_RWGB = 54
  • LED_STRIP_V2_CHANNEL_MAPPING_RWBG = 57
  • LED_STRIP_V2_CHANNEL_MAPPING_GRWB = 78
  • LED_STRIP_V2_CHANNEL_MAPPING_GRBW = 75
  • LED_STRIP_V2_CHANNEL_MAPPING_GBWR = 108
  • LED_STRIP_V2_CHANNEL_MAPPING_GBRW = 99
  • LED_STRIP_V2_CHANNEL_MAPPING_GWBR = 120
  • LED_STRIP_V2_CHANNEL_MAPPING_GWRB = 114
  • LED_STRIP_V2_CHANNEL_MAPPING_BRGW = 135
  • LED_STRIP_V2_CHANNEL_MAPPING_BRWG = 141
  • LED_STRIP_V2_CHANNEL_MAPPING_BGRW = 147
  • LED_STRIP_V2_CHANNEL_MAPPING_BGWR = 156
  • LED_STRIP_V2_CHANNEL_MAPPING_BWRG = 177
  • LED_STRIP_V2_CHANNEL_MAPPING_BWGR = 180
  • LED_STRIP_V2_CHANNEL_MAPPING_WRBG = 201
  • LED_STRIP_V2_CHANNEL_MAPPING_WRGB = 198
  • LED_STRIP_V2_CHANNEL_MAPPING_WGBR = 216
  • LED_STRIP_V2_CHANNEL_MAPPING_WGRB = 210
  • LED_STRIP_V2_CHANNEL_MAPPING_WBGR = 228
  • LED_STRIP_V2_CHANNEL_MAPPING_WBRG = 225
int led_strip_v2_get_channel_mapping(LEDStripV2 *led_strip_v2, uint8_t *ret_mapping)

Returns the currently used channel mapping as set by led_strip_v2_set_channel_mapping().

The following defines are available for this function:

  • LED_STRIP_V2_CHANNEL_MAPPING_RGB = 6
  • LED_STRIP_V2_CHANNEL_MAPPING_RBG = 9
  • LED_STRIP_V2_CHANNEL_MAPPING_BRG = 33
  • LED_STRIP_V2_CHANNEL_MAPPING_BGR = 36
  • LED_STRIP_V2_CHANNEL_MAPPING_GRB = 18
  • LED_STRIP_V2_CHANNEL_MAPPING_GBR = 24
  • LED_STRIP_V2_CHANNEL_MAPPING_RGBW = 27
  • LED_STRIP_V2_CHANNEL_MAPPING_RGWB = 30
  • LED_STRIP_V2_CHANNEL_MAPPING_RBGW = 39
  • LED_STRIP_V2_CHANNEL_MAPPING_RBWG = 45
  • LED_STRIP_V2_CHANNEL_MAPPING_RWGB = 54
  • LED_STRIP_V2_CHANNEL_MAPPING_RWBG = 57
  • LED_STRIP_V2_CHANNEL_MAPPING_GRWB = 78
  • LED_STRIP_V2_CHANNEL_MAPPING_GRBW = 75
  • LED_STRIP_V2_CHANNEL_MAPPING_GBWR = 108
  • LED_STRIP_V2_CHANNEL_MAPPING_GBRW = 99
  • LED_STRIP_V2_CHANNEL_MAPPING_GWBR = 120
  • LED_STRIP_V2_CHANNEL_MAPPING_GWRB = 114
  • LED_STRIP_V2_CHANNEL_MAPPING_BRGW = 135
  • LED_STRIP_V2_CHANNEL_MAPPING_BRWG = 141
  • LED_STRIP_V2_CHANNEL_MAPPING_BGRW = 147
  • LED_STRIP_V2_CHANNEL_MAPPING_BGWR = 156
  • LED_STRIP_V2_CHANNEL_MAPPING_BWRG = 177
  • LED_STRIP_V2_CHANNEL_MAPPING_BWGR = 180
  • LED_STRIP_V2_CHANNEL_MAPPING_WRBG = 201
  • LED_STRIP_V2_CHANNEL_MAPPING_WRGB = 198
  • LED_STRIP_V2_CHANNEL_MAPPING_WGBR = 216
  • LED_STRIP_V2_CHANNEL_MAPPING_WGRB = 210
  • LED_STRIP_V2_CHANNEL_MAPPING_WBGR = 228
  • LED_STRIP_V2_CHANNEL_MAPPING_WBRG = 225

Advanced Functions

int led_strip_v2_get_api_version(LEDStripV2 *led_strip_v2, uint8_t ret_api_version[3])

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

int led_strip_v2_get_response_expected(LEDStripV2 *led_strip_v2, uint8_t function_id, bool *ret_response_expected)

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by led_strip_v2_set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See led_strip_v2_set_response_expected() for the list of function ID defines available for this function.

int led_strip_v2_set_response_expected(LEDStripV2 *led_strip_v2, uint8_t function_id, bool response_expected)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID defines are available for this function:

  • LED_STRIP_V2_FUNCTION_SET_LED_VALUES = 1
  • LED_STRIP_V2_FUNCTION_SET_FRAME_DURATION = 3
  • LED_STRIP_V2_FUNCTION_SET_CLOCK_FREQUENCY = 7
  • LED_STRIP_V2_FUNCTION_SET_CHIP_TYPE = 9
  • LED_STRIP_V2_FUNCTION_SET_CHANNEL_MAPPING = 11
  • LED_STRIP_V2_FUNCTION_SET_FRAME_STARTED_CALLBACK_CONFIGURATION = 13
  • LED_STRIP_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • LED_STRIP_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • LED_STRIP_V2_FUNCTION_RESET = 243
  • LED_STRIP_V2_FUNCTION_WRITE_UID = 248
int led_strip_v2_set_response_expected_all(LEDStripV2 *led_strip_v2, bool response_expected)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

int led_strip_v2_get_spitfp_error_count(LEDStripV2 *led_strip_v2, uint32_t *ret_error_count_ack_checksum, uint32_t *ret_error_count_message_checksum, uint32_t *ret_error_count_frame, uint32_t *ret_error_count_overflow)

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.

int led_strip_v2_set_bootloader_mode(LEDStripV2 *led_strip_v2, uint8_t mode, uint8_t *ret_status)

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 defines are available for this function:

  • LED_STRIP_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • LED_STRIP_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • LED_STRIP_V2_BOOTLOADER_STATUS_OK = 0
  • LED_STRIP_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • LED_STRIP_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • LED_STRIP_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • LED_STRIP_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • LED_STRIP_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
int led_strip_v2_get_bootloader_mode(LEDStripV2 *led_strip_v2, uint8_t *ret_mode)

Returns the current bootloader mode, see led_strip_v2_set_bootloader_mode().

The following defines are available for this function:

  • LED_STRIP_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • LED_STRIP_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • LED_STRIP_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
int led_strip_v2_set_write_firmware_pointer(LEDStripV2 *led_strip_v2, uint32_t pointer)

Sets the firmware pointer for led_strip_v2_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.

int led_strip_v2_write_firmware(LEDStripV2 *led_strip_v2, uint8_t data[64], uint8_t *ret_status)

Writes 64 Bytes of firmware at the position as written by led_strip_v2_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.

int led_strip_v2_set_status_led_config(LEDStripV2 *led_strip_v2, uint8_t config)

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 defines are available for this function:

  • LED_STRIP_V2_STATUS_LED_CONFIG_OFF = 0
  • LED_STRIP_V2_STATUS_LED_CONFIG_ON = 1
  • LED_STRIP_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LED_STRIP_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int led_strip_v2_get_status_led_config(LEDStripV2 *led_strip_v2, uint8_t *ret_config)

Returns the configuration as set by led_strip_v2_set_status_led_config()

The following defines are available for this function:

  • LED_STRIP_V2_STATUS_LED_CONFIG_OFF = 0
  • LED_STRIP_V2_STATUS_LED_CONFIG_ON = 1
  • LED_STRIP_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • LED_STRIP_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int led_strip_v2_get_chip_temperature(LEDStripV2 *led_strip_v2, int16_t *ret_temperature)

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.

int led_strip_v2_reset(LEDStripV2 *led_strip_v2)

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!

int led_strip_v2_write_uid(LEDStripV2 *led_strip_v2, uint32_t uid)

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.

int led_strip_v2_read_uid(LEDStripV2 *led_strip_v2, uint32_t *ret_uid)

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

int led_strip_v2_get_identity(LEDStripV2 *led_strip_v2, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)

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. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

void led_strip_v2_register_callback(LEDStripV2 *led_strip_v2, int16_t callback_id, void *function, void *user_data)

Registers the given function with the given callback_id. The user_data will be passed as the last parameter to the function.

The available callback IDs with corresponding function signatures are listed below.

int led_strip_v2_set_frame_started_callback_configuration(LEDStripV2 *led_strip_v2, bool enable)

Enables/disables the LED_STRIP_V2_CALLBACK_FRAME_STARTED callback.

By default the callback is enabled.

int led_strip_v2_get_frame_started_callback_configuration(LEDStripV2 *led_strip_v2, bool *ret_enable)

Returns the configuration as set by led_strip_v2_set_frame_started_callback_configuration().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the led_strip_v2_register_callback() function. The parameters consist of the device object, the callback ID, the callback function and optional user data:

void my_callback(int p, void *user_data) {
    printf("parameter: %d\n", p);
}

led_strip_v2_register_callback(&led_strip_v2, LED_STRIP_V2_CALLBACK_EXAMPLE, (void *)my_callback, NULL);

The available constants with corresponding callback function signatures 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.

LED_STRIP_V2_CALLBACK_FRAME_STARTED
void callback(uint16_t length, void *user_data)

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 led_strip_v2_set_led_values().

Constants

LED_STRIP_V2_DEVICE_IDENTIFIER

This constant is used to identify a LED Strip Bricklet 2.0.

The led_strip_v2_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

LED_STRIP_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a LED Strip Bricklet 2.0.