This is the description of the C/C++ API bindings for the Ambient Light Bricklet 2.0. General information and technical specifications for the Ambient Light 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 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_ambient_light_v2.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
AmbientLightV2 al;
ambient_light_v2_create(&al, 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 illuminance
uint32_t illuminance;
if(ambient_light_v2_get_illuminance(&al, &illuminance) < 0) {
fprintf(stderr, "Could not get illuminance, probably timeout\n");
return 1;
}
printf("Illuminance: %f lx\n", illuminance/100.0);
printf("Press key to exit\n");
getchar();
ambient_light_v2_destroy(&al);
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 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_ambient_light_v2.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0
// Callback function for illuminance callback
void cb_illuminance(uint32_t illuminance, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Illuminance: %f lx\n", illuminance/100.0);
}
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
AmbientLightV2 al;
ambient_light_v2_create(&al, 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 illuminance callback to function cb_illuminance
ambient_light_v2_register_callback(&al,
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE,
(void (*)(void))cb_illuminance,
NULL);
// Set period for illuminance callback to 1s (1000ms)
// Note: The illuminance callback is only called every second
// if the illuminance has changed since the last call!
ambient_light_v2_set_illuminance_callback_period(&al, 1000);
printf("Press key to exit\n");
getchar();
ambient_light_v2_destroy(&al);
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
return 0;
}
|
Download (example_threshold.c)
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 51 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_ambient_light_v2.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0
// Callback function for illuminance reached callback
void cb_illuminance_reached(uint32_t illuminance, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Illuminance: %f lx\n", illuminance/100.0);
printf("Too bright, close the curtains!\n");
}
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
AmbientLightV2 al;
ambient_light_v2_create(&al, 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 threshold callbacks with a debounce time of 10 seconds (10000ms)
ambient_light_v2_set_debounce_period(&al, 10000);
// Register illuminance reached callback to function cb_illuminance_reached
ambient_light_v2_register_callback(&al,
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE_REACHED,
(void (*)(void))cb_illuminance_reached,
NULL);
// Configure threshold for illuminance "greater than 500 lx"
ambient_light_v2_set_illuminance_callback_threshold(&al, '>', 500*100, 0);
printf("Press key to exit\n");
getchar();
ambient_light_v2_destroy(&al);
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.
ambient_light_v2_create
(AmbientLightV2 *ambient_light_v2, const char *uid, IPConnection *ipcon)¶Parameters: |
|
---|
Creates the device object ambient_light_v2
with the unique device ID uid
and adds
it to the IPConnection ipcon
:
AmbientLightV2 ambient_light_v2;
ambient_light_v2_create(&ambient_light_v2, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected.
ambient_light_v2_destroy
(AmbientLightV2 *ambient_light_v2)¶Parameters: |
|
---|
Removes the device object ambient_light_v2
from its IPConnection and destroys it.
The device object cannot be used anymore afterwards.
ambient_light_v2_get_illuminance
(AmbientLightV2 *ambient_light_v2, uint32_t *ret_illuminance)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the illuminance of the ambient light sensor. The measurement range goes up to about 100000lux, but above 64000lux the precision starts to drop.
Changed in version 2.0.2 (Plugin): An illuminance of 0lux indicates an error condition where the sensor cannot
perform a reasonable measurement. This can happen with very dim or very bright
light conditions. In bright light conditions this might indicate that the sensor
is saturated and the configuration should be modified (ambient_light_v2_set_configuration()
)
to better match the light conditions.
If you want to get the illuminance periodically, it is recommended to use the
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback and set the period with
ambient_light_v2_set_illuminance_callback_period()
.
ambient_light_v2_set_configuration
(AmbientLightV2 *ambient_light_v2, uint8_t illuminance_range, uint8_t integration_time)¶Parameters: |
|
---|---|
Returns: |
|
Sets the configuration. It is possible to configure an illuminance range between 0-600lux and 0-64000lux and an integration time between 50ms and 400ms.
New in version 2.0.2 (Plugin): The unlimited illuminance range allows to measure up to about 100000lux, but above 64000lux the precision starts to drop.
A smaller illuminance range increases the resolution of the data. A longer integration time will result in less noise on the data.
Changed in version 2.0.2 (Plugin): If the actual measure illuminance is out-of-range then the current illuminance
range maximum +0.01lux is reported by ambient_light_v2_get_illuminance()
and the
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback. For example, 800001 for the 0-8000lux range.
Changed in version 2.0.2 (Plugin): With a long integration time the sensor might be saturated before the measured
value reaches the maximum of the selected illuminance range. In this case 0lux
is reported by ambient_light_v2_get_illuminance()
and the AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback.
If the measurement is out-of-range or the sensor is saturated then you should configure the next higher illuminance range. If the highest range is already in use, then start to reduce the integration time.
The following constants are available for this function:
For illuminance_range:
For integration_time:
ambient_light_v2_get_configuration
(AmbientLightV2 *ambient_light_v2, uint8_t *ret_illuminance_range, uint8_t *ret_integration_time)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by ambient_light_v2_set_configuration()
.
The following constants are available for this function:
For ret_illuminance_range:
For ret_integration_time:
ambient_light_v2_get_identity
(AmbientLightV2 *ambient_light_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.
ambient_light_v2_register_callback
(AmbientLightV2 *ambient_light_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.
ambient_light_v2_set_illuminance_callback_period
(AmbientLightV2 *ambient_light_v2, uint32_t period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback is triggered
periodically. A value of 0 turns the callback off.
The AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback is only triggered if the illuminance has changed
since the last triggering.
ambient_light_v2_get_illuminance_callback_period
(AmbientLightV2 *ambient_light_v2, uint32_t *ret_period)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by ambient_light_v2_set_illuminance_callback_period()
.
ambient_light_v2_set_illuminance_callback_threshold
(AmbientLightV2 *ambient_light_v2, char option, uint32_t min, uint32_t max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the illuminance is outside the min and max values |
'i' | Callback is triggered when the illuminance is inside the min and max values |
'<' | Callback is triggered when the illuminance is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the illuminance is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
ambient_light_v2_get_illuminance_callback_threshold
(AmbientLightV2 *ambient_light_v2, char *ret_option, uint32_t *ret_min, uint32_t *ret_max)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the threshold as set by ambient_light_v2_set_illuminance_callback_threshold()
.
The following constants are available for this function:
For ret_option:
ambient_light_v2_set_debounce_period
(AmbientLightV2 *ambient_light_v2, uint32_t debounce)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the threshold callbacks
are triggered, if the thresholds
keep being reached.
ambient_light_v2_get_debounce_period
(AmbientLightV2 *ambient_light_v2, uint32_t *ret_debounce)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the debounce period as set by ambient_light_v2_set_debounce_period()
.
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the ambient_light_v2_register_callback()
function:
void my_callback(int value, void *user_data) { printf("Value: %d\n", value); } ambient_light_v2_register_callback(&ambient_light_v2, AMBIENT_LIGHT_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.
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
¶void callback(uint32_t illuminance, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
ambient_light_v2_set_illuminance_callback_period()
. The parameter is the illuminance of the
ambient light sensor.
The AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE
callback is only triggered if the illuminance has changed since the
last triggering.
AMBIENT_LIGHT_V2_CALLBACK_ILLUMINANCE_REACHED
¶void callback(uint32_t illuminance, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
ambient_light_v2_set_illuminance_callback_threshold()
is reached.
The parameter is the illuminance of the ambient light sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by ambient_light_v2_set_debounce_period()
.
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.
ambient_light_v2_get_api_version
(AmbientLightV2 *ambient_light_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.
ambient_light_v2_get_response_expected
(AmbientLightV2 *ambient_light_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
ambient_light_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:
ambient_light_v2_set_response_expected
(AmbientLightV2 *ambient_light_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:
ambient_light_v2_set_response_expected_all
(AmbientLightV2 *ambient_light_v2, bool response_expected)¶Parameters: |
|
---|---|
Returns: |
|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
AMBIENT_LIGHT_V2_DEVICE_IDENTIFIER
¶This constant is used to identify a Ambient Light Bricklet 2.0.
The ambient_light_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.
AMBIENT_LIGHT_V2_DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Ambient Light Bricklet 2.0.