This is the description of the C/C++ API bindings for the Voltage/Current Bricklet. General information and technical specifications for the Voltage/Current 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 43 44 45 46 47 48 49 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_voltage_current.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Voltage/Current Bricklet
// Callback function for current callback
void cb_current(int32_t current, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Current: %f A\n", current/1000.0);
}
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
VoltageCurrent vc;
voltage_current_create(&vc, 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 current callback to function cb_current
voltage_current_register_callback(&vc,
VOLTAGE_CURRENT_CALLBACK_CURRENT,
(void (*)(void))cb_current,
NULL);
// Set period for current callback to 1s (1000ms)
// Note: The current callback is only called every second
// if the current has changed since the last call!
voltage_current_set_current_callback_period(&vc, 1000);
printf("Press key to exit\n");
getchar();
voltage_current_destroy(&vc);
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_voltage_current.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Voltage/Current Bricklet
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
VoltageCurrent vc;
voltage_current_create(&vc, 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 voltage
int32_t voltage;
if(voltage_current_get_voltage(&vc, &voltage) < 0) {
fprintf(stderr, "Could not get voltage, probably timeout\n");
return 1;
}
printf("Voltage: %f V\n", voltage/1000.0);
// Get current current
int32_t current;
if(voltage_current_get_current(&vc, ¤t) < 0) {
fprintf(stderr, "Could not get current, probably timeout\n");
return 1;
}
printf("Current: %f A\n", current/1000.0);
printf("Press key to exit\n");
getchar();
voltage_current_destroy(&vc);
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 | #include <stdio.h>
#include "ip_connection.h"
#include "bricklet_voltage_current.h"
#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Voltage/Current Bricklet
// Callback function for power reached callback
void cb_power_reached(int32_t power, void *user_data) {
(void)user_data; // avoid unused parameter warning
printf("Power: %f W\n", power/1000.0);
}
int main(void) {
// Create IP connection
IPConnection ipcon;
ipcon_create(&ipcon);
// Create device object
VoltageCurrent vc;
voltage_current_create(&vc, 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)
voltage_current_set_debounce_period(&vc, 10000);
// Register power reached callback to function cb_power_reached
voltage_current_register_callback(&vc,
VOLTAGE_CURRENT_CALLBACK_POWER_REACHED,
(void (*)(void))cb_power_reached,
NULL);
// Configure threshold for power "greater than 10 W"
voltage_current_set_power_callback_threshold(&vc, '>', 10*1000, 0);
printf("Press key to exit\n");
getchar();
voltage_current_destroy(&vc);
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.
voltage_current_create
(VoltageCurrent *voltage_current, const char *uid, IPConnection *ipcon)¶Parameters: |
|
---|
Creates the device object voltage_current
with the unique device ID uid
and adds
it to the IPConnection ipcon
:
VoltageCurrent voltage_current;
voltage_current_create(&voltage_current, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected.
voltage_current_destroy
(VoltageCurrent *voltage_current)¶Parameters: |
|
---|
Removes the device object voltage_current
from its IPConnection and destroys it.
The device object cannot be used anymore afterwards.
voltage_current_get_current
(VoltageCurrent *voltage_current, int32_t *ret_current)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the current.
If you want to get the current periodically, it is recommended to use the
VOLTAGE_CURRENT_CALLBACK_CURRENT
callback and set the period with
voltage_current_set_current_callback_period()
.
voltage_current_get_voltage
(VoltageCurrent *voltage_current, int32_t *ret_voltage)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the voltage.
If you want to get the voltage periodically, it is recommended to use the
VOLTAGE_CURRENT_CALLBACK_VOLTAGE
callback and set the period with
voltage_current_set_voltage_callback_period()
.
voltage_current_get_power
(VoltageCurrent *voltage_current, int32_t *ret_power)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the power.
If you want to get the power periodically, it is recommended to use the
VOLTAGE_CURRENT_CALLBACK_POWER
callback and set the period with
voltage_current_set_power_callback_period()
.
voltage_current_set_configuration
(VoltageCurrent *voltage_current, uint8_t averaging, uint8_t voltage_conversion_time, uint8_t current_conversion_time)¶Parameters: |
|
---|---|
Returns: |
|
Sets the configuration of the Voltage/Current Bricklet. It is possible to configure number of averages as well as voltage and current conversion time.
The following constants are available for this function:
For averaging:
For voltage_conversion_time:
For current_conversion_time:
voltage_current_get_configuration
(VoltageCurrent *voltage_current, uint8_t *ret_averaging, uint8_t *ret_voltage_conversion_time, uint8_t *ret_current_conversion_time)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by voltage_current_set_configuration()
.
The following constants are available for this function:
For ret_averaging:
For ret_voltage_conversion_time:
For ret_current_conversion_time:
voltage_current_set_calibration
(VoltageCurrent *voltage_current, uint16_t gain_multiplier, uint16_t gain_divisor)¶Parameters: |
|
---|---|
Returns: |
|
Since the shunt resistor that is used to measure the current is not perfectly precise, it needs to be calibrated by a multiplier and divisor if a very precise reading is needed.
For example, if you are expecting a measurement of 1000mA and you are measuring 1023mA, you can calibrate the Voltage/Current Bricklet by setting the multiplier to 1000 and the divisor to 1023.
voltage_current_get_calibration
(VoltageCurrent *voltage_current, uint16_t *ret_gain_multiplier, uint16_t *ret_gain_divisor)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the calibration as set by voltage_current_set_calibration()
.
voltage_current_get_identity
(VoltageCurrent *voltage_current, 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.
voltage_current_register_callback
(VoltageCurrent *voltage_current, 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.
voltage_current_set_current_callback_period
(VoltageCurrent *voltage_current, uint32_t period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the VOLTAGE_CURRENT_CALLBACK_CURRENT
callback is triggered
periodically. A value of 0 turns the callback off.
The VOLTAGE_CURRENT_CALLBACK_CURRENT
callback is only triggered if the current has changed since
the last triggering.
voltage_current_get_current_callback_period
(VoltageCurrent *voltage_current, uint32_t *ret_period)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by voltage_current_set_current_callback_period()
.
voltage_current_set_voltage_callback_period
(VoltageCurrent *voltage_current, uint32_t period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the VOLTAGE_CURRENT_CALLBACK_VOLTAGE
callback is triggered
periodically. A value of 0 turns the callback off.
The VOLTAGE_CURRENT_CALLBACK_VOLTAGE
callback is only triggered if the voltage has changed since
the last triggering.
voltage_current_get_voltage_callback_period
(VoltageCurrent *voltage_current, uint32_t *ret_period)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by voltage_current_set_voltage_callback_period()
.
voltage_current_set_power_callback_period
(VoltageCurrent *voltage_current, uint32_t period)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the VOLTAGE_CURRENT_CALLBACK_POWER
callback is triggered
periodically. A value of 0 turns the callback off.
The VOLTAGE_CURRENT_CALLBACK_POWER
callback is only triggered if the power has changed since the
last triggering.
voltage_current_get_power_callback_period
(VoltageCurrent *voltage_current, uint32_t *ret_period)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the period as set by voltage_current_get_power_callback_period()
.
voltage_current_set_current_callback_threshold
(VoltageCurrent *voltage_current, char option, int32_t min, int32_t max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the VOLTAGE_CURRENT_CALLBACK_CURRENT_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the current is outside the min and max values |
'i' | Callback is triggered when the current is inside the min and max values |
'<' | Callback is triggered when the current is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the current is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
voltage_current_get_current_callback_threshold
(VoltageCurrent *voltage_current, char *ret_option, int32_t *ret_min, int32_t *ret_max)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the threshold as set by voltage_current_set_current_callback_threshold()
.
The following constants are available for this function:
For ret_option:
voltage_current_set_voltage_callback_threshold
(VoltageCurrent *voltage_current, char option, int32_t min, int32_t max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the VOLTAGE_CURRENT_CALLBACK_VOLTAGE_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the voltage is outside the min and max values |
'i' | Callback is triggered when the voltage is inside the min and max values |
'<' | Callback is triggered when the voltage is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the voltage is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
voltage_current_get_voltage_callback_threshold
(VoltageCurrent *voltage_current, char *ret_option, int32_t *ret_min, int32_t *ret_max)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the threshold as set by voltage_current_set_voltage_callback_threshold()
.
The following constants are available for this function:
For ret_option:
voltage_current_set_power_callback_threshold
(VoltageCurrent *voltage_current, char option, int32_t min, int32_t max)¶Parameters: |
|
---|---|
Returns: |
|
Sets the thresholds for the VOLTAGE_CURRENT_CALLBACK_POWER_REACHED
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the power is outside the min and max values |
'i' | Callback is triggered when the power is inside the min and max values |
'<' | Callback is triggered when the power is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the power is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
voltage_current_get_power_callback_threshold
(VoltageCurrent *voltage_current, char *ret_option, int32_t *ret_min, int32_t *ret_max)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the threshold as set by voltage_current_set_power_callback_threshold()
.
The following constants are available for this function:
For ret_option:
voltage_current_set_debounce_period
(VoltageCurrent *voltage_current, uint32_t debounce)¶Parameters: |
|
---|---|
Returns: |
|
Sets the period with which the threshold callbacks
VOLTAGE_CURRENT_CALLBACK_CURRENT_REACHED
,VOLTAGE_CURRENT_CALLBACK_VOLTAGE_REACHED
,VOLTAGE_CURRENT_CALLBACK_POWER_REACHED
are triggered, if the thresholds
voltage_current_set_current_callback_threshold()
,voltage_current_set_voltage_callback_threshold()
,voltage_current_set_power_callback_threshold()
keep being reached.
voltage_current_get_debounce_period
(VoltageCurrent *voltage_current, uint32_t *ret_debounce)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the debounce period as set by voltage_current_set_debounce_period()
.
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the voltage_current_register_callback()
function:
void my_callback(int value, void *user_data) { printf("Value: %d\n", value); } voltage_current_register_callback(&voltage_current, VOLTAGE_CURRENT_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.
VOLTAGE_CURRENT_CALLBACK_CURRENT
¶void callback(int32_t current, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
voltage_current_set_current_callback_period()
. The parameter is the current of the
sensor.
The VOLTAGE_CURRENT_CALLBACK_CURRENT
callback is only triggered if the current has changed since
the last triggering.
VOLTAGE_CURRENT_CALLBACK_VOLTAGE
¶void callback(int32_t voltage, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
voltage_current_set_voltage_callback_period()
. The parameter is the voltage of
the sensor.
The VOLTAGE_CURRENT_CALLBACK_VOLTAGE
callback is only triggered if the voltage has changed since
the last triggering.
VOLTAGE_CURRENT_CALLBACK_POWER
¶void callback(int32_t power, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered periodically with the period that is set by
voltage_current_set_power_callback_period()
. The parameter is the power of the
sensor.
The VOLTAGE_CURRENT_CALLBACK_POWER
callback is only triggered if the power has changed since the
last triggering.
VOLTAGE_CURRENT_CALLBACK_CURRENT_REACHED
¶void callback(int32_t current, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
voltage_current_set_current_callback_threshold()
is reached.
The parameter is the current of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by voltage_current_set_debounce_period()
.
VOLTAGE_CURRENT_CALLBACK_VOLTAGE_REACHED
¶void callback(int32_t voltage, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
voltage_current_set_voltage_callback_threshold()
is reached.
The parameter is the voltage of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by voltage_current_set_debounce_period()
.
VOLTAGE_CURRENT_CALLBACK_POWER_REACHED
¶void callback(int32_t power, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered when the threshold as set by
voltage_current_set_power_callback_threshold()
is reached.
The parameter is the power of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by voltage_current_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.
voltage_current_get_api_version
(VoltageCurrent *voltage_current, 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.
voltage_current_get_response_expected
(VoltageCurrent *voltage_current, 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
voltage_current_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:
voltage_current_set_response_expected
(VoltageCurrent *voltage_current, 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:
voltage_current_set_response_expected_all
(VoltageCurrent *voltage_current, bool response_expected)¶Parameters: |
|
---|---|
Returns: |
|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
VOLTAGE_CURRENT_DEVICE_IDENTIFIER
¶This constant is used to identify a Voltage/Current Bricklet.
The voltage_current_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.
VOLTAGE_CURRENT_DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Voltage/Current Bricklet.