Software / API Bindings / C/C++ for Microcontrollers / API Reference and Examples / Bricklets / Accelerometer Bricklet 2.0

C/C++ for Microcontrollers - Accelerometer Bricklet 2.0¶

This is the description of the C/C++ for Microcontrollers API bindings for the Accelerometer Bricklet 2.0. General information and technical specifications for the Accelerometer Bricklet 2.0 are summarized in its hardware description.

An installation guide for the C/C++ for Microcontrollers API bindings is part of their general description.

Examples¶

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

Simple¶

Download (example_simple.c)

// This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.

#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_accelerometer_v2.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

static TF_AccelerometerV2 a;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_accelerometer_v2_create(&a, NULL, hal), "create device object");

    // Get current acceleration
    int32_t x, y, z;
    check(tf_accelerometer_v2_get_acceleration(&a, &x, &y, &z), "get acceleration");

    tf_hal_printf("Acceleration [X]: %d 1/%d g\n", x, 10000);
    tf_hal_printf("Acceleration [Y]: %d 1/%d g\n", y, 10000);
    tf_hal_printf("Acceleration [Z]: %d 1/%d g\n", z, 10000);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

Callback¶

Download (example_callback.c)

// This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.

#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_accelerometer_v2.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

// Callback function for acceleration callback
static void acceleration_handler(TF_AccelerometerV2 *device, int32_t x, int32_t y,
                                 int32_t z, void *user_data) {
    (void)device; (void)user_data; // avoid unused parameter warning

    tf_hal_printf("Acceleration [X]: %d 1/%d g\n", x, 10000);
    tf_hal_printf("Acceleration [Y]: %d 1/%d g\n", y, 10000);
    tf_hal_printf("Acceleration [Z]: %d 1/%d g\n", z, 10000);
    tf_hal_printf("\n");
}

static TF_AccelerometerV2 a;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_accelerometer_v2_create(&a, NULL, hal), "create device object");

    // Register acceleration callback to function acceleration_handler
    tf_accelerometer_v2_register_acceleration_callback(&a,
                                                       acceleration_handler,
                                                       NULL);

    // Set period for acceleration callback to 1s (1000ms)
    tf_accelerometer_v2_set_acceleration_callback_configuration(&a, 1000, false);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

API¶

Most functions of the C/C++ bindings for microcontrollers return an error code (e_code).

Possible error codes are:

TF_E_OK = 0
TF_E_TIMEOUT = -1
TF_E_INVALID_PARAMETER = -2
TF_E_NOT_SUPPORTED = -3
TF_E_UNKNOWN_ERROR_CODE = -4
TF_E_STREAM_OUT_OF_SYNC = -5
TF_E_INVALID_CHAR_IN_UID = -6
TF_E_UID_TOO_LONG = -7
TF_E_UID_OVERFLOW = -8
TF_E_TOO_MANY_DEVICES = -9
TF_E_DEVICE_NOT_FOUND = -10
TF_E_WRONG_DEVICE_TYPE = -11
TF_E_LOCKED = -12
TF_E_PORT_NOT_FOUND = -13

(as defined in errors.h) as well as the errors returned from the hardware abstraction layer (HAL) that is used.

Use :cpp:func`tf_hal_strerror` (defined in the HAL's header file) to get an error string for an error code.

Data returned from the device, when a getter is called, is handled via output parameters. These parameters are labeled with the ret_ prefix. The bindings will not write to an output parameter if NULL or nullptr is passed. This can be used to ignore outputs that you are not interested in.

None of the functions listed below are thread-safe. See the API bindings description for details.

Basic Functions¶

int tf_accelerometer_v2_create(TF_AccelerometerV2 *accelerometer_v2, const char *uid_or_port_name, TF_HAL *hal)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * uid – Type: const char * hal – Type: TF_HAL *
Returns:	e_code – Type: int

Creates the device object accelerometer_v2 with the optional unique device ID or port name uid_or_port_name and adds it to the HAL hal:

TF_AccelerometerV2 accelerometer_v2;
tf_accelerometer_v2_create(&accelerometer_v2, NULL, &hal);

Normally uid_or_port_name can stay NULL. For more details about this see section UID or Port Name.

int tf_accelerometer_v2_destroy(TF_AccelerometerV2 *accelerometer_v2)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Returns:	e_code – Type: int

Removes the device object accelerometer_v2 from its HAL and destroys it. The device object cannot be used anymore afterwards.

int tf_accelerometer_v2_get_acceleration(TF_AccelerometerV2 *accelerometer_v2, int32_t *ret_x, int32_t *ret_y, int32_t *ret_z)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_x – Type: int32_t, Unit: 1/10000 gₙ, Range: ? ret_y – Type: int32_t, Unit: 1/10000 gₙ, Range: ? ret_z – Type: int32_t, Unit: 1/10000 gₙ, Range: ?
Returns:	e_code – Type: int

Returns the acceleration in x, y and z direction. The values are given in gₙ/10000 (1gₙ = 9.80665m/s²). The range is configured with tf_accelerometer_v2_set_configuration().

If you want to get the acceleration periodically, it is recommended to use the Acceleration callback and set the period with tf_accelerometer_v2_set_acceleration_callback_configuration().

int tf_accelerometer_v2_set_configuration(TF_AccelerometerV2 *accelerometer_v2, uint8_t data_rate, uint8_t full_scale)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * data_rate – Type: uint8_t, Range: See constants, Default: 7 full_scale – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Configures the data rate and full scale range. Possible values are:

Data rate of 0.781Hz to 25600Hz.
Full scale range of ±2g up to ±8g.

Decreasing data rate or full scale range will also decrease the noise on the data.

The following constants are available for this function:

For data_rate:

TF_ACCELEROMETER_V2_DATA_RATE_0_781HZ = 0
TF_ACCELEROMETER_V2_DATA_RATE_1_563HZ = 1
TF_ACCELEROMETER_V2_DATA_RATE_3_125HZ = 2
TF_ACCELEROMETER_V2_DATA_RATE_6_2512HZ = 3
TF_ACCELEROMETER_V2_DATA_RATE_12_5HZ = 4
TF_ACCELEROMETER_V2_DATA_RATE_25HZ = 5
TF_ACCELEROMETER_V2_DATA_RATE_50HZ = 6
TF_ACCELEROMETER_V2_DATA_RATE_100HZ = 7
TF_ACCELEROMETER_V2_DATA_RATE_200HZ = 8
TF_ACCELEROMETER_V2_DATA_RATE_400HZ = 9
TF_ACCELEROMETER_V2_DATA_RATE_800HZ = 10
TF_ACCELEROMETER_V2_DATA_RATE_1600HZ = 11
TF_ACCELEROMETER_V2_DATA_RATE_3200HZ = 12
TF_ACCELEROMETER_V2_DATA_RATE_6400HZ = 13
TF_ACCELEROMETER_V2_DATA_RATE_12800HZ = 14
TF_ACCELEROMETER_V2_DATA_RATE_25600HZ = 15

For full_scale:

TF_ACCELEROMETER_V2_FULL_SCALE_2G = 0
TF_ACCELEROMETER_V2_FULL_SCALE_4G = 1
TF_ACCELEROMETER_V2_FULL_SCALE_8G = 2

int tf_accelerometer_v2_get_configuration(TF_AccelerometerV2 *accelerometer_v2, uint8_t *ret_data_rate, uint8_t *ret_full_scale)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_data_rate – Type: uint8_t, Range: See constants, Default: 7 ret_full_scale – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the configuration as set by tf_accelerometer_v2_set_configuration().

The following constants are available for this function:

For ret_data_rate:

TF_ACCELEROMETER_V2_DATA_RATE_0_781HZ = 0
TF_ACCELEROMETER_V2_DATA_RATE_1_563HZ = 1
TF_ACCELEROMETER_V2_DATA_RATE_3_125HZ = 2
TF_ACCELEROMETER_V2_DATA_RATE_6_2512HZ = 3
TF_ACCELEROMETER_V2_DATA_RATE_12_5HZ = 4
TF_ACCELEROMETER_V2_DATA_RATE_25HZ = 5
TF_ACCELEROMETER_V2_DATA_RATE_50HZ = 6
TF_ACCELEROMETER_V2_DATA_RATE_100HZ = 7
TF_ACCELEROMETER_V2_DATA_RATE_200HZ = 8
TF_ACCELEROMETER_V2_DATA_RATE_400HZ = 9
TF_ACCELEROMETER_V2_DATA_RATE_800HZ = 10
TF_ACCELEROMETER_V2_DATA_RATE_1600HZ = 11
TF_ACCELEROMETER_V2_DATA_RATE_3200HZ = 12
TF_ACCELEROMETER_V2_DATA_RATE_6400HZ = 13
TF_ACCELEROMETER_V2_DATA_RATE_12800HZ = 14
TF_ACCELEROMETER_V2_DATA_RATE_25600HZ = 15

For ret_full_scale:

TF_ACCELEROMETER_V2_FULL_SCALE_2G = 0
TF_ACCELEROMETER_V2_FULL_SCALE_4G = 1
TF_ACCELEROMETER_V2_FULL_SCALE_8G = 2

int tf_accelerometer_v2_set_info_led_config(TF_AccelerometerV2 *accelerometer_v2, uint8_t config)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * config – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Configures the info LED (marked as "Force" on the Bricklet) to be either turned off, turned on, or blink in heartbeat mode.

The following constants are available for this function:

For config:

TF_ACCELEROMETER_V2_INFO_LED_CONFIG_OFF = 0
TF_ACCELEROMETER_V2_INFO_LED_CONFIG_ON = 1
TF_ACCELEROMETER_V2_INFO_LED_CONFIG_SHOW_HEARTBEAT = 2

int tf_accelerometer_v2_get_info_led_config(TF_AccelerometerV2 *accelerometer_v2, uint8_t *ret_config)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the LED configuration as set by tf_accelerometer_v2_set_info_led_config()

The following constants are available for this function:

For ret_config:

TF_ACCELEROMETER_V2_INFO_LED_CONFIG_OFF = 0
TF_ACCELEROMETER_V2_INFO_LED_CONFIG_ON = 1
TF_ACCELEROMETER_V2_INFO_LED_CONFIG_SHOW_HEARTBEAT = 2

Advanced Functions¶

int tf_accelerometer_v2_set_filter_configuration(TF_AccelerometerV2 *accelerometer_v2, uint8_t iir_bypass, uint8_t low_pass_filter)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * iir_bypass – Type: uint8_t, Range: See constants, Default: 0 low_pass_filter – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Configures IIR Bypass filter mode and low pass filter roll off corner frequency.

The filter can be applied or bypassed and the corner frequency can be half or a ninth of the output data rate.

The following constants are available for this function:

For iir_bypass:

TF_ACCELEROMETER_V2_IIR_BYPASS_APPLIED = 0
TF_ACCELEROMETER_V2_IIR_BYPASS_BYPASSED = 1

For low_pass_filter:

TF_ACCELEROMETER_V2_LOW_PASS_FILTER_NINTH = 0
TF_ACCELEROMETER_V2_LOW_PASS_FILTER_HALF = 1

New in version 2.0.2 (Plugin).

int tf_accelerometer_v2_get_filter_configuration(TF_AccelerometerV2 *accelerometer_v2, uint8_t *ret_iir_bypass, uint8_t *ret_low_pass_filter)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_iir_bypass – Type: uint8_t, Range: See constants, Default: 0 ret_low_pass_filter – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the configuration as set by tf_accelerometer_v2_set_filter_configuration().

The following constants are available for this function:

For ret_iir_bypass:

TF_ACCELEROMETER_V2_IIR_BYPASS_APPLIED = 0
TF_ACCELEROMETER_V2_IIR_BYPASS_BYPASSED = 1

For ret_low_pass_filter:

TF_ACCELEROMETER_V2_LOW_PASS_FILTER_NINTH = 0
TF_ACCELEROMETER_V2_LOW_PASS_FILTER_HALF = 1

New in version 2.0.2 (Plugin).

int tf_accelerometer_v2_get_spitfp_error_count(TF_AccelerometerV2 *accelerometer_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)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_error_count_ack_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_message_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_frame – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_overflow – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: 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.

int tf_accelerometer_v2_set_status_led_config(TF_AccelerometerV2 *accelerometer_v2, uint8_t config)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

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 constants are available for this function:

For config:

TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_OFF = 0
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_ON = 1
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_accelerometer_v2_get_status_led_config(TF_AccelerometerV2 *accelerometer_v2, uint8_t *ret_config)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by tf_accelerometer_v2_set_status_led_config()

The following constants are available for this function:

For ret_config:

TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_OFF = 0
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_ON = 1
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_ACCELEROMETER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_accelerometer_v2_get_chip_temperature(TF_AccelerometerV2 *accelerometer_v2, int16_t *ret_temperature)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_temperature – Type: int16_t, Unit: 1 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	e_code – Type: int

Returns the temperature 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 tf_accelerometer_v2_reset(TF_AccelerometerV2 *accelerometer_v2)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Returns:	e_code – Type: int

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 tf_accelerometer_v2_get_identity(TF_AccelerometerV2 *accelerometer_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)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_uid – Type: char[8] ret_connected_uid – Type: char[8] ret_position – Type: char, Range: ['a' to 'h', 'z'] ret_hardware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_firmware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_device_identifier – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

int tf_accelerometer_v2_set_acceleration_callback_configuration(TF_AccelerometerV2 *accelerometer_v2, uint32_t period, bool value_has_to_change)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 value_has_to_change – Type: bool, Default: false
Returns:	e_code – Type: int

The period is the period with which the Acceleration 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.

If this callback is enabled, the Continuous Acceleration 16 Bit callback and Continuous Acceleration 8 Bit callback will automatically be disabled.

int tf_accelerometer_v2_get_acceleration_callback_configuration(TF_AccelerometerV2 *accelerometer_v2, uint32_t *ret_period, bool *ret_value_has_to_change)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_period – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 ret_value_has_to_change – Type: bool, Default: false
Returns:	e_code – Type: int

Returns the callback configuration as set by tf_accelerometer_v2_set_acceleration_callback_configuration().

int tf_accelerometer_v2_set_continuous_acceleration_configuration(TF_AccelerometerV2 *accelerometer_v2, bool enable_x, bool enable_y, bool enable_z, uint8_t resolution)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * enable_x – Type: bool, Default: false enable_y – Type: bool, Default: false enable_z – Type: bool, Default: false resolution – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

For high throughput of acceleration data (> 1000Hz) you have to use the Continuous Acceleration 16 Bit or Continuous Acceleration 8 Bit callbacks.

You can enable the callback for each axis (x, y, z) individually and choose a resolution of 8 bit or 16 bit.

If at least one of the axis is enabled and the resolution is set to 8 bit, the Continuous Acceleration 8 Bit callback is activated. If at least one of the axis is enabled and the resolution is set to 16 bit, the Continuous Acceleration 16 Bit callback is activated.

The returned values are raw ADC data. If you want to put this data into a FFT to determine the occurrences of specific frequencies we recommend that you use the data as is. It has all of the ADC noise in it. This noise looks like pure noise at first glance, but it might still have some frequnecy information in it that can be utilized by the FFT.

Otherwise you have to use the following formulas that depend on the configured resolution (8/16 bit) and the full scale range (see tf_accelerometer_v2_set_configuration()) to calculate the data in gₙ/10000 (same unit that is returned by tf_accelerometer_v2_get_acceleration()):

16 bit, full scale 2g: acceleration = value * 625 / 1024
16 bit, full scale 4g: acceleration = value * 1250 / 1024
16 bit, full scale 8g: acceleration = value * 2500 / 1024

If a resolution of 8 bit is used, only the 8 most significant bits will be transferred, so you can use the following formulas:

8 bit, full scale 2g: acceleration = value * 256 * 625 / 1024
8 bit, full scale 4g: acceleration = value * 256 * 1250 / 1024
8 bit, full scale 8g: acceleration = value * 256 * 2500 / 1024

If no axis is enabled, both callbacks are disabled. If one of the continuous callbacks is enabled, the Acceleration callback is disabled.

The maximum throughput depends on the exact configuration:

Number of axis enabled	Throughput 8 bit	Throughout 16 bit
1	25600Hz	25600Hz
2	25600Hz	15000Hz
3	20000Hz	10000Hz

The following constants are available for this function:

For resolution:

TF_ACCELEROMETER_V2_RESOLUTION_8BIT = 0
TF_ACCELEROMETER_V2_RESOLUTION_16BIT = 1

int tf_accelerometer_v2_get_continuous_acceleration_configuration(TF_AccelerometerV2 *accelerometer_v2, bool *ret_enable_x, bool *ret_enable_y, bool *ret_enable_z, uint8_t *ret_resolution)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_enable_x – Type: bool, Default: false ret_enable_y – Type: bool, Default: false ret_enable_z – Type: bool, Default: false ret_resolution – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the continuous acceleration configuration as set by tf_accelerometer_v2_set_continuous_acceleration_configuration().

The following constants are available for this function:

For ret_resolution:

TF_ACCELEROMETER_V2_RESOLUTION_8BIT = 0
TF_ACCELEROMETER_V2_RESOLUTION_16BIT = 1

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding tf_accelerometer_v2_register_*_callback function. The user_data passed to the registration function as well as the device that triggered the callback are passed to the registered callback handler.

Only one handler can be registered to a callback at the same time. To deregister a callback, call the tf_accelerometer_v2_register_*_callback function with NULL as handler.

Note

Using callbacks for recurring events is preferred compared to using getters. Polling for a callback requires writing one byte only. See here Optimizing Performance.

Warning

Calling bindings function from inside a callback handler is not allowed. See here Thread safety.

int tf_accelerometer_v2_register_acceleration_callback(TF_AccelerometerV2 *accelerometer_v2, TF_AccelerometerV2_AccelerationHandler handler, void *user_data)¶

void handler(TF_AccelerometerV2 *accelerometer_v2, int32_t x, int32_t y, int32_t z, void *user_data)

Callback Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * x – Type: int32_t, Unit: 1/10000 gₙ, Range: ? y – Type: int32_t, Unit: 1/10000 gₙ, Range: ? z – Type: int32_t, Unit: 1/10000 gₙ, Range: ? user_data – Type: void *

This callback is triggered periodically according to the configuration set by tf_accelerometer_v2_set_acceleration_callback_configuration().

The parameters are the same as tf_accelerometer_v2_get_acceleration().

int tf_accelerometer_v2_register_continuous_acceleration_16_bit_callback(TF_AccelerometerV2 *accelerometer_v2, TF_AccelerometerV2_ContinuousAcceleration16BitHandler handler, void *user_data)¶

void handler(TF_AccelerometerV2 *accelerometer_v2, int16_t acceleration[30], void *user_data)

Callback Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * acceleration – Type: int16_t[30], Unit: ? gₙ, Range: ? user_data – Type: void *

Returns 30 acceleration values with 16 bit resolution. The data rate can be configured with tf_accelerometer_v2_set_configuration() and this callback can be enabled with tf_accelerometer_v2_set_continuous_acceleration_configuration().

Otherwise you have to use the following formulas that depend on the full scale range (see tf_accelerometer_v2_set_configuration()) to calculate the data in gₙ/10000 (same unit that is returned by tf_accelerometer_v2_get_acceleration()):

Full scale 2g: acceleration = value * 625 / 1024
Full scale 4g: acceleration = value * 1250 / 1024
Full scale 8g: acceleration = value * 2500 / 1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

x, y, z enabled: "x, y, z, ..." 10x repeated
x, z enabled: "x, z, ..." 15x repeated
y enabled: "y, ..." 30x repeated

int tf_accelerometer_v2_register_continuous_acceleration_8_bit_callback(TF_AccelerometerV2 *accelerometer_v2, TF_AccelerometerV2_ContinuousAcceleration8BitHandler handler, void *user_data)¶

void handler(TF_AccelerometerV2 *accelerometer_v2, int8_t acceleration[60], void *user_data)

Callback Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * acceleration – Type: int8_t[60], Unit: ? gₙ, Range: ? user_data – Type: void *

Returns 60 acceleration values with 8 bit resolution. The data rate can be configured with tf_accelerometer_v2_set_configuration() and this callback can be enabled with tf_accelerometer_v2_set_continuous_acceleration_configuration().

Full scale 2g: acceleration = value * 256 * 625 / 1024
Full scale 4g: acceleration = value * 256 * 1250 / 1024
Full scale 8g: acceleration = value * 256 * 2500 / 1024

The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:

x, y, z enabled: "x, y, z, ..." 20x repeated
x, z enabled: "x, z, ..." 30x repeated
y enabled: "y, ..." 60x repeated

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object.

int tf_accelerometer_v2_get_response_expected(TF_AccelerometerV2 *accelerometer_v2, uint8_t function_id, bool *ret_response_expected)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * function_id – Type: uint8_t, Range: See constants
Output Parameters:	ret_response_expected – Type: bool
Returns:	e_code – Type: int

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 tf_accelerometer_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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

TF_ACCELEROMETER_V2_FUNCTION_SET_CONFIGURATION = 2
TF_ACCELEROMETER_V2_FUNCTION_SET_ACCELERATION_CALLBACK_CONFIGURATION = 4
TF_ACCELEROMETER_V2_FUNCTION_SET_INFO_LED_CONFIG = 6
TF_ACCELEROMETER_V2_FUNCTION_SET_CONTINUOUS_ACCELERATION_CONFIGURATION = 9
TF_ACCELEROMETER_V2_FUNCTION_SET_FILTER_CONFIGURATION = 13
TF_ACCELEROMETER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_ACCELEROMETER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_ACCELEROMETER_V2_FUNCTION_RESET = 243
TF_ACCELEROMETER_V2_FUNCTION_WRITE_UID = 248

int tf_accelerometer_v2_set_response_expected(TF_AccelerometerV2 *accelerometer_v2, uint8_t function_id, bool response_expected)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * function_id – Type: uint8_t, Range: See constants response_expected – Type: bool
Returns:	e_code – Type: int

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.

The following constants are available for this function:

For function_id:

TF_ACCELEROMETER_V2_FUNCTION_SET_CONFIGURATION = 2
TF_ACCELEROMETER_V2_FUNCTION_SET_ACCELERATION_CALLBACK_CONFIGURATION = 4
TF_ACCELEROMETER_V2_FUNCTION_SET_INFO_LED_CONFIG = 6
TF_ACCELEROMETER_V2_FUNCTION_SET_CONTINUOUS_ACCELERATION_CONFIGURATION = 9
TF_ACCELEROMETER_V2_FUNCTION_SET_FILTER_CONFIGURATION = 13
TF_ACCELEROMETER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_ACCELEROMETER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_ACCELEROMETER_V2_FUNCTION_RESET = 243
TF_ACCELEROMETER_V2_FUNCTION_WRITE_UID = 248

int tf_accelerometer_v2_set_response_expected_all(TF_AccelerometerV2 *accelerometer_v2, bool response_expected)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * response_expected – Type: bool
Returns:	e_code – Type: int

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

Internal Functions¶

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

int tf_accelerometer_v2_set_bootloader_mode(TF_AccelerometerV2 *accelerometer_v2, uint8_t mode, uint8_t *ret_status)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * mode – Type: uint8_t, Range: See constants
Output Parameters:	ret_status – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

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 constants are available for this function:

For mode:

TF_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE = 1
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For ret_status:

TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_OK = 0
TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
TF_ACCELEROMETER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5

int tf_accelerometer_v2_get_bootloader_mode(TF_AccelerometerV2 *accelerometer_v2, uint8_t *ret_mode)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_mode – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

Returns the current bootloader mode, see tf_accelerometer_v2_set_bootloader_mode().

The following constants are available for this function:

For ret_mode:

TF_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE = 1
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_ACCELEROMETER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

int tf_accelerometer_v2_set_write_firmware_pointer(TF_AccelerometerV2 *accelerometer_v2, uint32_t pointer)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * pointer – Type: uint32_t, Unit: 1 B, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Sets the firmware pointer for tf_accelerometer_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 tf_accelerometer_v2_write_firmware(TF_AccelerometerV2 *accelerometer_v2, const uint8_t data[64], uint8_t *ret_status)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * data – Type: const uint8_t[64], Range: [0 to 255]
Output Parameters:	ret_status – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

Writes 64 Bytes of firmware at the position as written by tf_accelerometer_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 tf_accelerometer_v2_write_uid(TF_AccelerometerV2 *accelerometer_v2, uint32_t uid)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 * uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

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 tf_accelerometer_v2_read_uid(TF_AccelerometerV2 *accelerometer_v2, uint32_t *ret_uid)¶

Parameters:	accelerometer_v2 – Type: TF_AccelerometerV2 *
Output Parameters:	ret_uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

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

Constants¶

TF_ACCELEROMETER_V2_DEVICE_IDENTIFIER¶

This constant is used to identify a Accelerometer Bricklet 2.0.

The functions tf_accelerometer_v2_get_identity() and tf_hal_get_device_info() have a device_identifier output parameter to specify the Brick's or Bricklet's type.

TF_ACCELEROMETER_V2_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Accelerometer Bricklet 2.0.