This is the description of the C/C++ 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++ API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_accelerometer_v2.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Accelerometer Bricklet 2.0
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
AccelerometerV2 a;
accelerometer_v2_create(&a, 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 acceleration
int32_t x, y, z;
if(accelerometer_v2_get_acceleration(&a, &x, &y, &z) < 0) {
fprintf(stderr, "Could not get acceleration, probably timeout\n");
return 1;
}
printf("Acceleration [X]: %f g\n", x/10000.0);
printf("Acceleration [Y]: %f g\n", y/10000.0);
printf("Acceleration [Z]: %f g\n", z/10000.0);
printf("Press key to exit\n");
getchar();
accelerometer_v2_destroy(&a);
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
return 0;
}
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_accelerometer_v2.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Accelerometer Bricklet 2.0
// Callback function for acceleration callback
void cb_acceleration(int32_t x, int32_t y, int32_t z, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Acceleration [X]: %f g\n", x/10000.0);
printf("Acceleration [Y]: %f g\n", y/10000.0);
printf("Acceleration [Z]: %f g\n", z/10000.0);
printf("\n");
}
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
AccelerometerV2 a;
accelerometer_v2_create(&a, 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 acceleration callback to function cb_acceleration
accelerometer_v2_register_callback(&a,
ACCELEROMETER_V2_CALLBACK_ACCELERATION,
(void (*)(void))cb_acceleration,
NULL);
// Set period for acceleration callback to 1s (1000ms)
accelerometer_v2_set_acceleration_callback_configuration(&a, 1000, false);
printf("Press key to exit\n");
getchar();
accelerometer_v2_destroy(&a);
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
return 0;
}
|
Most functions of the C/C++ bindings return an error code (e_code
).
Data returned from the device, when a getter is called,
is handled via output parameters. These parameters are labeled with the
ret_
prefix.
Possible error codes are:
as defined in ip_connection.h
.
All functions listed below are thread-safe.
accelerometer_v2_create
(AccelerometerV2 *accelerometer_v2, const char *uid, IPConnection *ipcon)¶Parameters: |
|
---|
Creates the device object accelerometer_v2
with the unique device ID uid
and adds
it to the IPConnection ipcon
:
AccelerometerV2 accelerometer_v2;
accelerometer_v2_create(&accelerometer_v2, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected.
accelerometer_v2_destroy
(AccelerometerV2 *accelerometer_v2)¶Parameters: |
|
---|
Removes the device object accelerometer_v2
from its IPConnection and destroys it.
The device object cannot be used anymore afterwards.
accelerometer_v2_get_acceleration
(AccelerometerV2 *accelerometer_v2, int32_t *ret_x, int32_t *ret_y, int32_t *ret_z)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
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 accelerometer_v2_set_configuration()
.
If you want to get the acceleration periodically, it is recommended
to use the ACCELEROMETER_V2_CALLBACK_ACCELERATION
callback and set the period with
accelerometer_v2_set_acceleration_callback_configuration()
.
accelerometer_v2_set_configuration
(AccelerometerV2 *accelerometer_v2, uint8_t data_rate, uint8_t full_scale)¶Parameters: |
|
---|---|
Returns: |
|
Configures the data rate and full scale range. Possible values are:
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:
For full_scale:
accelerometer_v2_get_configuration
(AccelerometerV2 *accelerometer_v2, uint8_t *ret_data_rate, uint8_t *ret_full_scale)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by accelerometer_v2_set_configuration()
.
The following constants are available for this function:
For ret_data_rate:
For ret_full_scale:
accelerometer_v2_set_info_led_config
(AccelerometerV2 *accelerometer_v2, uint8_t config)¶Parameters: |
|
---|---|
Returns: |
|
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:
accelerometer_v2_get_info_led_config
(AccelerometerV2 *accelerometer_v2, uint8_t *ret_config)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the LED configuration as set by accelerometer_v2_set_info_led_config()
The following constants are available for this function:
For ret_config:
accelerometer_v2_set_filter_configuration
(AccelerometerV2 *accelerometer_v2, uint8_t iir_bypass, uint8_t low_pass_filter)¶Parameters: |
|
---|---|
Returns: |
|
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:
For low_pass_filter:
New in version 2.0.2 (Plugin).
accelerometer_v2_get_filter_configuration
(AccelerometerV2 *accelerometer_v2, uint8_t *ret_iir_bypass, uint8_t *ret_low_pass_filter)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by accelerometer_v2_set_filter_configuration()
.
The following constants are available for this function:
For ret_iir_bypass:
For ret_low_pass_filter:
New in version 2.0.2 (Plugin).
accelerometer_v2_get_spitfp_error_count
(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: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
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.
accelerometer_v2_set_status_led_config
(AccelerometerV2 *accelerometer_v2, uint8_t config)¶Parameters: |
|
---|---|
Returns: |
|
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:
accelerometer_v2_get_status_led_config
(AccelerometerV2 *accelerometer_v2, uint8_t *ret_config)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by accelerometer_v2_set_status_led_config()
The following constants are available for this function:
For ret_config:
accelerometer_v2_get_chip_temperature
(AccelerometerV2 *accelerometer_v2, int16_t *ret_temperature)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
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.
accelerometer_v2_reset
(AccelerometerV2 *accelerometer_v2)¶Parameters: |
|
---|---|
Returns: |
|
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!
accelerometer_v2_get_identity
(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: |
|
---|---|
Output Parameters: |
|
Returns: |
|
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.
accelerometer_v2_register_callback
(AccelerometerV2 *accelerometer_v2, int16_t callback_id, void (*function)(void), void *user_data)¶Parameters: |
|
---|
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.
accelerometer_v2_set_acceleration_callback_configuration
(AccelerometerV2 *accelerometer_v2, uint32_t period, bool value_has_to_change)¶Parameters: |
|
---|---|
Returns: |
|
The period is the period with which the ACCELEROMETER_V2_CALLBACK_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 ACCELEROMETER_V2_CALLBACK_CONTINUOUS_ACCELERATION_16_BIT
callback
and ACCELEROMETER_V2_CALLBACK_CONTINUOUS_ACCELERATION_8_BIT
callback will automatically be disabled.
accelerometer_v2_get_acceleration_callback_configuration
(AccelerometerV2 *accelerometer_v2, uint32_t *ret_period, bool *ret_value_has_to_change)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the callback configuration as set by
accelerometer_v2_set_acceleration_callback_configuration()
.
accelerometer_v2_set_continuous_acceleration_configuration
(AccelerometerV2 *accelerometer_v2, bool enable_x, bool enable_y, bool enable_z, uint8_t resolution)¶Parameters: |
|
---|---|
Returns: |
|
For high throughput of acceleration data (> 1000Hz) you have to use the
ACCELEROMETER_V2_CALLBACK_CONTINUOUS_ACCELERATION_16_BIT
or ACCELEROMETER_V2_CALLBACK_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 ACCELEROMETER_V2_CALLBACK_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 ACCELEROMETER_V2_CALLBACK_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 accelerometer_v2_set_configuration()
) to calculate
the data in gₙ/10000 (same unit that is returned by accelerometer_v2_get_acceleration()
):
If a resolution of 8 bit is used, only the 8 most significant bits will be transferred, so you can use the following formulas:
If no axis is enabled, both callbacks are disabled. If one of the continuous
callbacks is enabled, the ACCELEROMETER_V2_CALLBACK_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:
accelerometer_v2_get_continuous_acceleration_configuration
(AccelerometerV2 *accelerometer_v2, bool *ret_enable_x, bool *ret_enable_y, bool *ret_enable_z, uint8_t *ret_resolution)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the continuous acceleration configuration as set by
accelerometer_v2_set_continuous_acceleration_configuration()
.
The following constants are available for this function:
For ret_resolution:
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the accelerometer_v2_register_callback()
function:
void my_callback(int value, void *user_data) { printf("Value: %d\n", value); } accelerometer_v2_register_callback(&accelerometer_v2, ACCELEROMETER_V2_CALLBACK_EXAMPLE, (void (*)(void))my_callback, NULL);
The available constants with corresponding 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.
ACCELEROMETER_V2_CALLBACK_ACCELERATION
¶void callback(int32_t x, int32_t y, int32_t z, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically according to the configuration set by
accelerometer_v2_set_acceleration_callback_configuration()
.
The parameters are the same as accelerometer_v2_get_acceleration()
.
ACCELEROMETER_V2_CALLBACK_CONTINUOUS_ACCELERATION_16_BIT
¶void callback(int16_t acceleration[30], void *user_data)
Callback Parameters: |
|
---|
Returns 30 acceleration values with 16 bit resolution. The data rate can
be configured with accelerometer_v2_set_configuration()
and this callback can be
enabled with accelerometer_v2_set_continuous_acceleration_configuration()
.
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
full scale range (see accelerometer_v2_set_configuration()
) to calculate
the data in gₙ/10000 (same unit that is returned by accelerometer_v2_get_acceleration()
):
The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:
ACCELEROMETER_V2_CALLBACK_CONTINUOUS_ACCELERATION_8_BIT
¶void callback(int8_t acceleration[60], void *user_data)
Callback Parameters: |
|
---|
Returns 60 acceleration values with 8 bit resolution. The data rate can
be configured with accelerometer_v2_set_configuration()
and this callback can be
enabled with accelerometer_v2_set_continuous_acceleration_configuration()
.
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
full scale range (see accelerometer_v2_set_configuration()
) to calculate
the data in gₙ/10000 (same unit that is returned by accelerometer_v2_get_acceleration()
):
The data is formated in the sequence "x, y, z, x, y, z, ..." depending on the enabled axis. Examples:
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.
accelerometer_v2_get_api_version
(AccelerometerV2 *accelerometer_v2, uint8_t ret_api_version[3])¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the version of the API definition 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.
accelerometer_v2_get_response_expected
(AccelerometerV2 *accelerometer_v2, uint8_t function_id, bool *ret_response_expected)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
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
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:
accelerometer_v2_set_response_expected
(AccelerometerV2 *accelerometer_v2, uint8_t function_id, bool response_expected)¶Parameters: |
|
---|---|
Returns: |
|
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 sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For function_id:
accelerometer_v2_set_response_expected_all
(AccelerometerV2 *accelerometer_v2, bool response_expected)¶Parameters: |
|
---|---|
Returns: |
|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
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.
accelerometer_v2_set_bootloader_mode
(AccelerometerV2 *accelerometer_v2, uint8_t mode, uint8_t *ret_status)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
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:
For ret_status:
accelerometer_v2_get_bootloader_mode
(AccelerometerV2 *accelerometer_v2, uint8_t *ret_mode)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the current bootloader mode, see accelerometer_v2_set_bootloader_mode()
.
The following constants are available for this function:
For ret_mode:
accelerometer_v2_set_write_firmware_pointer
(AccelerometerV2 *accelerometer_v2, uint32_t pointer)¶Parameters: |
|
---|---|
Returns: |
|
Sets the firmware pointer for 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.
accelerometer_v2_write_firmware
(AccelerometerV2 *accelerometer_v2, uint8_t data[64], uint8_t *ret_status)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Writes 64 Bytes of firmware at the position as written by
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.
accelerometer_v2_write_uid
(AccelerometerV2 *accelerometer_v2, uint32_t uid)¶Parameters: |
|
---|---|
Returns: |
|
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.
accelerometer_v2_read_uid
(AccelerometerV2 *accelerometer_v2, uint32_t *ret_uid)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
ACCELEROMETER_V2_DEVICE_IDENTIFIER
¶This constant is used to identify a Accelerometer Bricklet 2.0.
The accelerometer_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.
ACCELEROMETER_V2_DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Accelerometer Bricklet 2.0.