C/C++ - Distance IR Bricklet 2.0

This is the description of the C/C++ API bindings for the Distance IR Bricklet 2.0. General information and technical specifications for the Distance IR 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_distance_ir_v2.h"

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

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

    // Create device object
    DistanceIRV2 dir;
    distance_ir_v2_create(&dir, 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

    // Get current distance
    uint16_t distance;
    if(distance_ir_v2_get_distance(&dir, &distance) < 0) {
        fprintf(stderr, "Could not get distance, probably timeout\n");
        return 1;
    }

    printf("Distance: %f cm\n", distance/10.0);

    printf("Press key to exit\n");
    getchar();
    distance_ir_v2_destroy(&dir);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Callback

Download (example_callback.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_distance_ir_v2.h"

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

// Callback function for distance callback
void cb_distance(uint16_t distance, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Distance: %f cm\n", distance/10.0);
}

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

    // Create device object
    DistanceIRV2 dir;
    distance_ir_v2_create(&dir, 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

    // Register distance callback to function cb_distance
    distance_ir_v2_register_callback(&dir,
                                     DISTANCE_IR_V2_CALLBACK_DISTANCE,
                                     (void *)cb_distance,
                                     NULL);

    // Set period for distance callback to 1s (1000ms) without a threshold
    distance_ir_v2_set_distance_callback_configuration(&dir, 1000, false, 'x', 0, 0);

    printf("Press key to exit\n");
    getchar();
    distance_ir_v2_destroy(&dir);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Threshold

Download (example_threshold.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_distance_ir_v2.h"

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

// Callback function for distance callback
void cb_distance(uint16_t distance, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Distance: %f cm\n", distance/10.0);
}

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

    // Create device object
    DistanceIRV2 dir;
    distance_ir_v2_create(&dir, 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

    // Register distance callback to function cb_distance
    distance_ir_v2_register_callback(&dir,
                                     DISTANCE_IR_V2_CALLBACK_DISTANCE,
                                     (void *)cb_distance,
                                     NULL);

    // Configure threshold for distance "smaller than 30 cm"
    // with a debounce period of 1s (1000ms)
    distance_ir_v2_set_distance_callback_configuration(&dir, 1000, false, '<', 30*10, 0);

    printf("Press key to exit\n");
    getchar();
    distance_ir_v2_destroy(&dir);
    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 distance_ir_v2_create(DistanceIRV2 *distance_ir_v2, const char *uid, IPConnection *ipcon)

Creates the device object distance_ir_v2 with the unique device ID uid and adds it to the IPConnection ipcon:

DistanceIRV2 distance_ir_v2;
distance_ir_v2_create(&distance_ir_v2, "YOUR_DEVICE_UID", &ipcon);

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

void distance_ir_v2_destroy(DistanceIRV2 *distance_ir_v2)

Removes the device object distance_ir_v2 from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int distance_ir_v2_get_distance(DistanceIRV2 *distance_ir_v2, uint16_t *ret_distance)

Returns the distance measured by the sensor. The value is in mm and possible distance ranges are 40 to 300, 100 to 800 and 200 to 1500, depending on the selected IR sensor.

If you want to get the value periodically, it is recommended to use the DISTANCE_IR_V2_CALLBACK_DISTANCE callback. You can set the callback configuration with distance_ir_v2_set_distance_callback_configuration().

int distance_ir_v2_get_analog_value(DistanceIRV2 *distance_ir_v2, uint32_t *ret_analog_value)

Returns the analog value as read by a analog-to-digital converter. The value has 21 bit with a range of 0 to 2097151.

This is unfiltered raw data. We made sure that the integration time of the ADC is shorter then the measurement interval of the sensor (10ms vs 16.5ms). So there is no information lost.

If you want to do your own calibration or create your own lookup table you can use this value.

If you want to get the value periodically, it is recommended to use the DISTANCE_IR_V2_CALLBACK_ANALOG_VALUE callback. You can set the callback configuration with distance_ir_v2_set_analog_value_callback_configuration().

int distance_ir_v2_set_moving_average_configuration(DistanceIRV2 *distance_ir_v2, uint16_t moving_average_length)

Sets the length of a moving averaging for the resistance and temperature.

Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

The range for the averaging is 1-1000.

New data is gathered every ~10ms. With a moving average of length 1000 the resulting averaging window has a length of approximately 10s. If you want to do long term measurements the longest moving average will give the cleanest results.

The default value is 25.

int distance_ir_v2_get_moving_average_configuration(DistanceIRV2 *distance_ir_v2, uint16_t *ret_moving_average_length)

Returns the moving average configuration as set by distance_ir_v2_set_moving_average_configuration().

int distance_ir_v2_set_distance_led_config(DistanceIRV2 *distance_ir_v2, uint8_t config)

Configures the distance LED to be either turned off, turned on, blink in heartbeat mode or show the distance (brighter = object is nearer).

The default value is 3 (show distance).

The following defines are available for this function:

  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_OFF = 0
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_ON = 1
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3
int distance_ir_v2_get_distance_led_config(DistanceIRV2 *distance_ir_v2, uint8_t *ret_config)

Returns the LED configuration as set by distance_ir_v2_set_distance_led_config()

The following defines are available for this function:

  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_OFF = 0
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_ON = 1
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_SHOW_HEARTBEAT = 2
  • DISTANCE_IR_V2_DISTANCE_LED_CONFIG_SHOW_DISTANCE = 3
int distance_ir_v2_set_sensor_type(DistanceIRV2 *distance_ir_v2, uint8_t sensor)

Sets the sensor type.

The Bricklet comes configured with the correct sensor type and the type is saved in flash (i.e. the Bricklet retains the information if power is lost).

If you want to change the sensor you can set the type in Brick Viewer, you will likely never need to call this function from your program.

The following defines are available for this function:

  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A41 = 0
  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A21 = 1
  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A02 = 2
int distance_ir_v2_get_sensor_type(DistanceIRV2 *distance_ir_v2, uint8_t *ret_sensor)

Returns the sensor type as set by distance_ir_v2_set_sensor_type().

The following defines are available for this function:

  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A41 = 0
  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A21 = 1
  • DISTANCE_IR_V2_SENSOR_TYPE_2Y0A02 = 2

Advanced Functions

int distance_ir_v2_get_api_version(DistanceIRV2 *distance_ir_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 distance_ir_v2_get_response_expected(DistanceIRV2 *distance_ir_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 distance_ir_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 distance_ir_v2_set_response_expected() for the list of function ID defines available for this function.

int distance_ir_v2_set_response_expected(DistanceIRV2 *distance_ir_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:

  • DISTANCE_IR_V2_FUNCTION_SET_DISTANCE_CALLBACK_CONFIGURATION = 2
  • DISTANCE_IR_V2_FUNCTION_SET_ANALOG_VALUE_CALLBACK_CONFIGURATION = 6
  • DISTANCE_IR_V2_FUNCTION_SET_MOVING_AVERAGE_CONFIGURATION = 9
  • DISTANCE_IR_V2_FUNCTION_SET_DISTANCE_LED_CONFIG = 11
  • DISTANCE_IR_V2_FUNCTION_SET_SENSOR_TYPE = 13
  • DISTANCE_IR_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • DISTANCE_IR_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • DISTANCE_IR_V2_FUNCTION_RESET = 243
  • DISTANCE_IR_V2_FUNCTION_WRITE_UID = 248
int distance_ir_v2_set_response_expected_all(DistanceIRV2 *distance_ir_v2, bool response_expected)

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

int distance_ir_v2_get_spitfp_error_count(DistanceIRV2 *distance_ir_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 distance_ir_v2_set_bootloader_mode(DistanceIRV2 *distance_ir_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:

  • DISTANCE_IR_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • DISTANCE_IR_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_OK = 0
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • DISTANCE_IR_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
int distance_ir_v2_get_bootloader_mode(DistanceIRV2 *distance_ir_v2, uint8_t *ret_mode)

Returns the current bootloader mode, see distance_ir_v2_set_bootloader_mode().

The following defines are available for this function:

  • DISTANCE_IR_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • DISTANCE_IR_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • DISTANCE_IR_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
int distance_ir_v2_set_write_firmware_pointer(DistanceIRV2 *distance_ir_v2, uint32_t pointer)

Sets the firmware pointer for distance_ir_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 distance_ir_v2_write_firmware(DistanceIRV2 *distance_ir_v2, uint8_t data[64], uint8_t *ret_status)

Writes 64 Bytes of firmware at the position as written by distance_ir_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 distance_ir_v2_set_status_led_config(DistanceIRV2 *distance_ir_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:

  • DISTANCE_IR_V2_STATUS_LED_CONFIG_OFF = 0
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_ON = 1
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int distance_ir_v2_get_status_led_config(DistanceIRV2 *distance_ir_v2, uint8_t *ret_config)

Returns the configuration as set by distance_ir_v2_set_status_led_config()

The following defines are available for this function:

  • DISTANCE_IR_V2_STATUS_LED_CONFIG_OFF = 0
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_ON = 1
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • DISTANCE_IR_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
int distance_ir_v2_get_chip_temperature(DistanceIRV2 *distance_ir_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 distance_ir_v2_reset(DistanceIRV2 *distance_ir_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 distance_ir_v2_write_uid(DistanceIRV2 *distance_ir_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 distance_ir_v2_read_uid(DistanceIRV2 *distance_ir_v2, uint32_t *ret_uid)

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

int distance_ir_v2_get_identity(DistanceIRV2 *distance_ir_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 distance_ir_v2_register_callback(DistanceIRV2 *distance_ir_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 distance_ir_v2_set_distance_callback_configuration(DistanceIRV2 *distance_ir_v2, uint32_t period, bool value_has_to_change, char option, uint16_t min, uint16_t max)

The period in ms is the period with which the DISTANCE_IR_V2_CALLBACK_DISTANCE 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 the value has changed. If the value 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the DISTANCE_IR_V2_CALLBACK_DISTANCE callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following defines are available for this function:

  • DISTANCE_IR_V2_THRESHOLD_OPTION_OFF = 'x'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_SMALLER = '<'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_GREATER = '>'
int distance_ir_v2_get_distance_callback_configuration(DistanceIRV2 *distance_ir_v2, uint32_t *ret_period, bool *ret_value_has_to_change, char *ret_option, uint16_t *ret_min, uint16_t *ret_max)

Returns the callback configuration as set by distance_ir_v2_set_distance_callback_configuration().

The following defines are available for this function:

  • DISTANCE_IR_V2_THRESHOLD_OPTION_OFF = 'x'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_SMALLER = '<'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_GREATER = '>'
int distance_ir_v2_set_analog_value_callback_configuration(DistanceIRV2 *distance_ir_v2, uint32_t period, bool value_has_to_change, char option, uint32_t min, uint32_t max)

The period in ms is the period with which the DISTANCE_IR_V2_CALLBACK_ANALOG_VALUE 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 the value has changed. If the value 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the DISTANCE_IR_V2_CALLBACK_ANALOG_VALUE callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The default value is (0, false, 'x', 0, 0).

The following defines are available for this function:

  • DISTANCE_IR_V2_THRESHOLD_OPTION_OFF = 'x'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_SMALLER = '<'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_GREATER = '>'
int distance_ir_v2_get_analog_value_callback_configuration(DistanceIRV2 *distance_ir_v2, uint32_t *ret_period, bool *ret_value_has_to_change, char *ret_option, uint32_t *ret_min, uint32_t *ret_max)

Returns the callback configuration as set by distance_ir_v2_set_analog_value_callback_configuration().

The following defines are available for this function:

  • DISTANCE_IR_V2_THRESHOLD_OPTION_OFF = 'x'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_SMALLER = '<'
  • DISTANCE_IR_V2_THRESHOLD_OPTION_GREATER = '>'

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the distance_ir_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);
}

distance_ir_v2_register_callback(&distance_ir_v2, DISTANCE_IR_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.

DISTANCE_IR_V2_CALLBACK_DISTANCE
void callback(uint16_t distance, void *user_data)

This callback is triggered periodically according to the configuration set by distance_ir_v2_set_distance_callback_configuration().

The parameter is the same as distance_ir_v2_get_distance().

DISTANCE_IR_V2_CALLBACK_ANALOG_VALUE
void callback(uint32_t analog_value, void *user_data)

This callback is triggered periodically according to the configuration set by distance_ir_v2_set_analog_value_callback_configuration().

The parameter is the same as distance_ir_v2_get_analog_value().

Constants

DISTANCE_IR_V2_DEVICE_IDENTIFIER

This constant is used to identify a Distance IR Bricklet 2.0.

The distance_ir_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.

DISTANCE_IR_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Distance IR Bricklet 2.0.