C/C++ - Industrial Digital In 4 Bricklet

This is the description of the C/C++ API bindings for the Industrial Digital In 4 Bricklet. General information and technical specifications for the Industrial Digital In 4 Bricklet are summarized in its hardware description.

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

Examples

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

Simple

Download (example_simple.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_industrial_digital_in_4.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Industrial Digital In 4 Bricklet

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    IndustrialDigitalIn4 idi4;
    industrial_digital_in_4_create(&idi4, 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 value as bitmask
    uint16_t value_mask;
    if(industrial_digital_in_4_get_value(&idi4, &value_mask) < 0) {
        fprintf(stderr, "Could not get value as bitmask, probably timeout\n");
        return 1;
    }

    printf("Value Mask: %u\n", value_mask);

    printf("Press key to exit\n");
    getchar();
    industrial_digital_in_4_destroy(&idi4);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Interrupt

Download (example_interrupt.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_industrial_digital_in_4.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Industrial Digital In 4 Bricklet

// Callback function for interrupt callback
void cb_interrupt(uint16_t interrupt_mask, uint16_t value_mask, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Interrupt Mask: %u\n", interrupt_mask);
    printf("Value Mask: %u\n", value_mask);
    printf("\n");
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    IndustrialDigitalIn4 idi4;
    industrial_digital_in_4_create(&idi4, 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 interrupt callback to function cb_interrupt
    industrial_digital_in_4_register_callback(&idi4,
                                              INDUSTRIAL_DIGITAL_IN_4_CALLBACK_INTERRUPT,
                                              (void (*)(void))cb_interrupt,
                                              NULL);

    // Enable interrupt on pin 0
    industrial_digital_in_4_set_interrupt(&idi4, 1 << 0);

    printf("Press key to exit\n");
    getchar();
    industrial_digital_in_4_destroy(&idi4);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

API

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 output parameters. These parameters are labeled with the ret_ prefix.

Possible error codes are:

  • E_OK = 0
  • E_TIMEOUT = -1
  • E_NO_STREAM_SOCKET = -2
  • E_HOSTNAME_INVALID = -3
  • E_NO_CONNECT = -4
  • E_NO_THREAD = -5
  • E_NOT_ADDED = -6 (unused since bindings version 2.0.0)
  • E_ALREADY_CONNECTED = -7
  • E_NOT_CONNECTED = -8
  • E_INVALID_PARAMETER = -9
  • E_NOT_SUPPORTED = -10
  • E_UNKNOWN_ERROR_CODE = -11
  • E_STREAM_OUT_OF_SYNC = -12
  • E_INVALID_UID = -13
  • E_NON_ASCII_CHAR_IN_SECRET = -14

as defined in ip_connection.h.

All functions listed below are thread-safe.

Basic Functions

void industrial_digital_in_4_create(IndustrialDigitalIn4 *industrial_digital_in_4, const char *uid, IPConnection *ipcon)

Creates the device object industrial_digital_in_4 with the unique device ID uid and adds it to the IPConnection ipcon:

IndustrialDigitalIn4 industrial_digital_in_4;
industrial_digital_in_4_create(&industrial_digital_in_4, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected (see examples above).

void industrial_digital_in_4_destroy(IndustrialDigitalIn4 *industrial_digital_in_4)

Removes the device object industrial_digital_in_4 from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int industrial_digital_in_4_get_value(IndustrialDigitalIn4 *industrial_digital_in_4, uint16_t *ret_value_mask)

Returns the input value with a bitmask. The bitmask is 16bit long, true refers to high and false refers to low.

For example: The value 3 or 0b0011 means that pins 0-1 are high and the other pins are low.

If no groups are used (see industrial_digital_in_4_set_group()), the pins correspond to the markings on the IndustrialDigital In 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

int industrial_digital_in_4_get_edge_count(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t pin, bool reset_counter, uint32_t *ret_count)

Returns the current value of the edge counter for the selected pin. You can configure the edges that are counted with industrial_digital_in_4_set_edge_count_config().

If you set the reset counter to true, the count is set back to 0 directly after it is read.

New in version 2.0.1 (Plugin).

Advanced Functions

int industrial_digital_in_4_set_group(IndustrialDigitalIn4 *industrial_digital_in_4, char group[4])

Sets a group of Digital In 4 Bricklets that should work together. You can find Bricklets that can be grouped together with industrial_digital_in_4_get_available_for_group().

The group consists of 4 elements. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Each element can either be one of the ports ('a' to 'd') or 'n' if it should not be used.

For example: If you have two Digital In 4 Bricklets connected to port A and port B respectively, you could call with ['a', 'b', 'n', 'n'].

Now the pins on the Digital In 4 on port A are assigned to 0-3 and the pins on the Digital In 4 on port B are assigned to 4-7. It is now possible to call industrial_digital_in_4_get_value() and read out two Bricklets at the same time.

Changing the group configuration resets all edge counter configurations and values.

int industrial_digital_in_4_get_group(IndustrialDigitalIn4 *industrial_digital_in_4, char ret_group[4])

Returns the group as set by industrial_digital_in_4_set_group()

int industrial_digital_in_4_get_available_for_group(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t *ret_available)

Returns a bitmask of ports that are available for grouping. For example the value 5 or 0b0101 means: Port A and port C are connected to Bricklets that can be grouped together.

int industrial_digital_in_4_set_edge_count_config(IndustrialDigitalIn4 *industrial_digital_in_4, uint16_t selection_mask, uint8_t edge_type, uint8_t debounce)

Configures the edge counter for the selected pins. A bitmask of 9 or 0b1001 will enable the edge counter for pins 0 and 3.

The edge type parameter configures if rising edges, falling edges or both are counted if the pin is configured for input. Possible edge types are:

  • 0 = rising (default)
  • 1 = falling
  • 2 = both

The debounce time is given in ms.

Configuring an edge counter resets its value to 0.

If you don't know what any of this means, just leave it at default. The default configuration is very likely OK for you.

Default values: 0 (edge type) and 100ms (debounce time)

The following constants are available for this function:

  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_RISING = 0
  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_FALLING = 1
  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

int industrial_digital_in_4_get_edge_count_config(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t pin, uint8_t *ret_edge_type, uint8_t *ret_debounce)

Returns the edge type and debounce time for the selected pin as set by industrial_digital_in_4_set_edge_count_config().

The following constants are available for this function:

  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_RISING = 0
  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_FALLING = 1
  • INDUSTRIAL_DIGITAL_IN_4_EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

int industrial_digital_in_4_get_api_version(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t ret_api_version[3])

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.

int industrial_digital_in_4_get_response_expected(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t function_id, bool *ret_response_expected)

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 industrial_digital_in_4_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.

The following constants are available for this function:

  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_GROUP = 2
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_DEBOUNCE_PERIOD = 5
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_INTERRUPT = 7
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_EDGE_COUNT_CONFIG = 11
int industrial_digital_in_4_set_response_expected(IndustrialDigitalIn4 *industrial_digital_in_4, uint8_t function_id, bool response_expected)

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

The following constants are available for this function:

  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_GROUP = 2
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_DEBOUNCE_PERIOD = 5
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_INTERRUPT = 7
  • INDUSTRIAL_DIGITAL_IN_4_FUNCTION_SET_EDGE_COUNT_CONFIG = 11
int industrial_digital_in_4_set_response_expected_all(IndustrialDigitalIn4 *industrial_digital_in_4, bool response_expected)

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

int industrial_digital_in_4_get_identity(IndustrialDigitalIn4 *industrial_digital_in_4, 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)

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.

Callback Configuration Functions

void industrial_digital_in_4_register_callback(IndustrialDigitalIn4 *industrial_digital_in_4, int16_t callback_id, void (*function)(void), void *user_data)

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.

int industrial_digital_in_4_set_debounce_period(IndustrialDigitalIn4 *industrial_digital_in_4, uint32_t debounce)

Sets the debounce period of the INDUSTRIAL_DIGITAL_IN_4_CALLBACK_INTERRUPT callback in ms.

For example: If you set this value to 100, you will get the interrupt maximal every 100ms. This is necessary if something that bounces is connected to the Digital In 4 Bricklet, such as a button.

The default value is 100.

int industrial_digital_in_4_get_debounce_period(IndustrialDigitalIn4 *industrial_digital_in_4, uint32_t *ret_debounce)

Returns the debounce period as set by industrial_digital_in_4_set_debounce_period().

int industrial_digital_in_4_set_interrupt(IndustrialDigitalIn4 *industrial_digital_in_4, uint16_t interrupt_mask)

Sets the pins on which an interrupt is activated with a bitmask. Interrupts are triggered on changes of the voltage level of the pin, i.e. changes from high to low and low to high.

For example: An interrupt bitmask of 9 or 0b1001 will enable the interrupt for pins 0 and 3.

The interrupts use the grouping as set by industrial_digital_in_4_set_group().

The interrupt is delivered with the INDUSTRIAL_DIGITAL_IN_4_CALLBACK_INTERRUPT callback.

int industrial_digital_in_4_get_interrupt(IndustrialDigitalIn4 *industrial_digital_in_4, uint16_t *ret_interrupt_mask)

Returns the interrupt bitmask as set by industrial_digital_in_4_set_interrupt().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the industrial_digital_in_4_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);
}

industrial_digital_in_4_register_callback(&industrial_digital_in_4, INDUSTRIAL_DIGITAL_IN_4_CALLBACK_EXAMPLE, (void (*)(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.

INDUSTRIAL_DIGITAL_IN_4_CALLBACK_INTERRUPT
void callback(uint16_t interrupt_mask, uint16_t value_mask, void *user_data)

This callback is triggered whenever a change of the voltage level is detected on pins where the interrupt was activated with industrial_digital_in_4_set_interrupt().

The values are a bitmask that specifies which interrupts occurred and the current value bitmask.

For example:

  • (1, 1) or (0b0001, 0b0001) means that an interrupt on pin 0 occurred and currently pin 0 is high and pins 1-3 are low.
  • (9, 14) or (0b1001, 0b1110) means that interrupts on pins 0 and 3 occurred and currently pin 0 is low and pins 1-3 are high.

Constants

INDUSTRIAL_DIGITAL_IN_4_DEVICE_IDENTIFIER

This constant is used to identify a Industrial Digital In 4 Bricklet.

The industrial_digital_in_4_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.

INDUSTRIAL_DIGITAL_IN_4_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Industrial Digital In 4 Bricklet.