This is the description of the C/C++ API bindings for the Color Bricklet. General information and technical specifications for the Color Bricklet 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_color.h"
#define HOST "localhost"
#define PORT 4223
#define UID "abc" // Change to your UID
int main() {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
Color c;
color_create(&c, UID, &ipcon);
// Connect to brickd
if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
fprintf(stderr, "Could not connect\n");
exit(1);
}
// Don't use device before ipcon is connected
// Get current color
uint16_t r; uint16_t g; uint16_t b; uint16_t cl;
if(color_get_color(&c, &r, &g, &b, &cl) < 0) {
fprintf(stderr, "Could not get value, probably timeout\n");
exit(1);
}
printf("Color(R): %u\n", r);
printf("Color(G): %u\n", g);
printf("Color(B): %u\n", b);
printf("Color(C): %u\n", cl);
printf("\n");
printf("Press key to exit\n");
getchar();
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
}
|
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_color.h"
#define HOST "localhost"
#define PORT 4223
#define UID "abc" // Change to your UID
// Callback for color
void cb_color(uint16_t r, uint16_t g, uint16_t b, uint16_t c, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Color(R): %u\n", r);
printf("Color(G): %u\n", g);
printf("Color(B): %u\n", b);
printf("Color(C): %u\n", c);
printf("\n");
}
int main() {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
Color c;
color_create(&c, UID, &ipcon);
// Connect to brickd
if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
fprintf(stderr, "Could not connect\n");
exit(1);
}
// Don't use device before ipcon is connected
// Set Period for color callback to 1s (1000ms)
// Note: The callback is only called every second if the
// color has changed since the last call!
color_set_color_callback_period(&c, 1000);
// Register color callback to function cb_color
color_register_callback(&c,
COLOR_CALLBACK_COLOR,
(void *)cb_color,
NULL);
printf("Press key to exit\n");
getchar();
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
}
|
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 52 53 54 55 56 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_color.h"
#define HOST "localhost"
#define PORT 4223
#define UID "abc" // Change to your UID
// Callback for color threshold reached
void cb_reached(uint16_t r, uint16_t g, uint16_t b, uint16_t c, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Color(R): %u\n", r);
printf("Color(G): %u\n", g);
printf("Color(B): %u\n", b);
printf("Color(C): %u\n", c);
printf("\n");
}
int main() {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
Color c;
color_create(&c, UID, &ipcon);
// Connect to brickd
if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
fprintf(stderr, "Could not connect\n");
exit(1);
}
// Don't use device before ipcon is connected
// Get threshold callbacks with a debounce time of 10 seconds (10000ms)
color_set_debounce_period(&c, 10000);
// Register threshold reached callback to function cb_reached
color_register_callback(&c,
COLOR_CALLBACK_COLOR_REACHED,
(void *)cb_reached,
NULL);
// Configure threshold for color values,
// RED greater than 100
// GREEN greater than 200
// BLUE greater than 300
// CLEAR greater than 400
color_set_color_callback_threshold(&c, '>', 100, 0, 200, 0, 300, 0, 400, 0);
printf("Press key to exit\n");
getchar();
ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
}
|
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:
as defined in ip_connection.h.
All functions listed below are thread-safe.
Creates the device object color with the unique device ID uid and adds it to the IPConnection ipcon:
Color color;
color_create(&color, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected (see examples above).
Removes the device object color from its IPConnection and destroys it. The device object cannot be used anymore afterwards.
Returns the measured color of the sensor. The values have a range of 0 to 65535.
The red (r), green (g), blue (b) and clear (c) colors are measured with four different photodiodes that are responsive at different wavelengths:
If you want to get the color periodically, it is recommended to use the callback COLOR_CALLBACK_COLOR and set the period with color_set_color_callback_period().
Turns the LED on.
Turns the LED off.
Returns the state of the LED. Possible values are:
The following defines are available for this function:
Sets the configuration of the sensor. Gain and integration time can be configured in this way.
For configuring the gain:
For configuring the integration time:
Increasing the gain enables the sensor to detect a color from a higher distance.
The integration time provides a trade-off between conversion time and accuracy. With a longer integration time the values read will be more accurate but it will take longer time to get the conversion results.
The default values are 60x gain and 154ms integration time.
The following defines are available for this function:
Returns the configuration as set by color_set_config().
The following defines are available for this function:
Returns the illuminance affected by the gain and integration time as set by color_set_config(). To get the illuminance in Lux apply this formula:
lux = illuminance * 700 / gain / integration_time
To get a correct illuminance measurement make sure that the color values themself are not saturated. The color value (R, G or B) is saturated if it is equal to the maximum value of 65535. In that case you have to reduce the gain, see color_set_config().
Returns the color temperature in Kelvin.
To get a correct color temperature measurement make sure that the color values themself are not saturated. The color value (R, G or B) is saturated if it is equal to the maximum value of 65535. In that case you have to reduce the gain, see color_set_config().
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.
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 color_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 color_set_response_expected() for the list of function ID defines available for this function.
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 and callbacks it is always disabled.
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:
Changes the response expected flag for all setter and callback configuration functions of this device at once.
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.
Registers a callback with ID id to the function callback. The user_data will be given as a parameter of the callback.
The available IDs with corresponding function signatures are listed below.
Sets the period in ms with which the COLOR_CALLBACK_COLOR callback is triggered periodically. A value of 0 turns the callback off.
COLOR_CALLBACK_COLOR is only triggered if the color has changed since the last triggering.
The default value is 0.
Returns the period as set by color_set_color_callback_period().
Sets the thresholds for the COLOR_CALLBACK_COLOR_REACHED callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the temperature is outside the min and max values |
'i' | Callback is triggered when the temperature is inside the min and max values |
'<' | Callback is triggered when the temperature is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the temperature is greater than the min value (max is ignored) |
The default value is ('x', 0, 0, 0, 0, 0, 0, 0, 0).
The following defines are available for this function:
Returns the threshold as set by color_set_color_callback_threshold().
The following defines are available for this function:
Sets the period in ms with which the threshold callback
is triggered, if the threshold
keeps being reached.
The default value is 100.
Returns the debounce period as set by color_set_debounce_period().
Sets the period in ms with which the COLOR_CALLBACK_ILLUMINANCE callback is triggered periodically. A value of 0 turns the callback off.
COLOR_CALLBACK_ILLUMINANCE is only triggered if the illuminance has changed since the last triggering.
The default value is 0.
Returns the period as set by color_set_illuminance_callback_period().
Sets the period in ms with which the COLOR_CALLBACK_COLOR_TEMPERATURE callback is triggered periodically. A value of 0 turns the callback off.
COLOR_CALLBACK_COLOR_TEMPERATURE is only triggered if the color temperature has changed since the last triggering.
The default value is 0.
Returns the period as set by color_set_color_temperature_callback_period().
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the color_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); } color_register_callback(&color, COLOR_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.
void callback(uint16_t r, uint16_t g, uint16_t b, uint16_t c, void *user_data)
This callback is triggered periodically with the period that is set by color_set_color_callback_period(). The parameter is the color of the sensor as RGBC.
COLOR_CALLBACK_COLOR is only triggered if the color has changed since the last triggering.
void callback(uint16_t r, uint16_t g, uint16_t b, uint16_t c, void *user_data)
This callback is triggered when the threshold as set by color_set_color_callback_threshold() is reached. The parameter is the color of the sensor as RGBC.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by color_set_debounce_period().
void callback(uint32_t illuminance, void *user_data)
This callback is triggered periodically with the period that is set by color_set_illuminance_callback_period(). The parameter is the illuminance. See color_get_illuminance() for how to interpret this value.
COLOR_CALLBACK_ILLUMINANCE is only triggered if the illuminance has changed since the last triggering.
void callback(uint16_t color_temperature, void *user_data)
This callback is triggered periodically with the period that is set by color_set_color_temperature_callback_period(). The parameter is the color temperature in Kelvin.
COLOR_CALLBACK_COLOR_TEMPERATURE is only triggered if the color temperature has changed since the last triggering.
This constant is used to identify a Color Bricklet.
The color_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.