C/C++ - API Bindings

Note

There is an extra section for Objective-C and iOS.

The C/C++ bindings allow you to control Bricks and Bricklets from your C/C++ programs. The ZIP file for the bindings contains:

  • in source/ the source code of the bindings
  • in examples/ the examples for every Brick and Bricklet

Requirements

  • C compiler (C99 compatible) or C++ compiler

Installation

To keep the C/C++ bindings stupid and simple, they only have dependencies that are available nearly everywhere, thus making it possible to compile into any project hassle-free. We do not offer a precompiled library, since it would be a pain in the ass to provide them for all combinations of architectures and operating systems. This means, the bindings should work on most architectures (ARM, x86, etc.) and on most operating systems (Windows and POSIX systems, such as Linux and Mac OS X, etc.).

Because there is no precompiled library for the C/C++ bindings there is nothing to install as such. The recommended way of using the bindings is to include their source code directly into your C/C++ project. The next section shows some examples about how to do that.

Testing an Example

To test a C/C++ example Brick Daemon and Brick Viewer have to be installed first. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon and helps to figure out basic information about the connected Bricks and Bricklets.

As an example we will compile the Stepper Brick configuration example with GCC on the command line and with some IDEs. For that we have to copy the IP Connection and the Stepper Brick bindings from the source/ folder as well as the example_configuration.c from the examples/brick/stepper/ folder into a new folder:

example_project/
 -> ip_connection.c
 -> ip_connection.h
 -> brick_stepper.c
 -> brick_stepper.h
 -> example_configuration.c

In the example HOST and PORT specify at which network address the Stepper Brick can be found. If it is connected locally to USB then localhost and 4223 is correct. The UID value has to be changed to the UID of the connected Stepper Brick, which you can figure out using Brick Viewer:

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change to your UID

GCC

The only dependency on Unix-like systems is pthreads, therefore a compilation of the example with GCC on Linux and Mac OS X looks like this:

gcc -pthread -o example *.c

On Windows Win32 is used for threading and WinSock2 (ws2_32) for the network connection. Under MinGW we can compile the example as following (the library linking must come after the source):

gcc -o example.exe *.c -lws2_32 -ladvapi32

The simplest way to use the bindings in a C++ project is to rename the required source files from *.c to *.cpp. Then the compiler will treat the source code as C++ and does the right thing automatically.

Visual Studio

With Visual Studio we can use the example_project/ folder too. The simplest way to use the bindings in a Visual C++ project is to rename the required source files from *.c to *.cpp. Then the compiler will treat the source code as C++ and does the right thing automatically. This will also avoid the problem that the Visual Studio compiler supports the C89 standard only, but the bindings uses the newer C99 standard.

IDE

Now a new project can be created in Visual Studio by clicking:

  • File
  • New
  • Project From Existing Code
  • Choose Type "Visual C++"
  • Choose example_project/
  • Choose a project name
  • Click Next
  • Choose "Console Application"
  • Click Finish

Then ws2_32.lib (WinSock2) and advapi32.lib have to included by clicking:

  • Project
  • Properties
  • Linker
  • Input, option "Additional Dependencies"
  • Add ws2_32.lib;advapi32.lib;

Older version of Visual Studio don't come with stdint.h. A compatible version can be found here. If necessary download it to the example_project/ folder.

That's it, now the project can be compiled an executed!

Command Line

The Visual Studio compiler can also be used from the command line in the example_project/ folder:

cl.exe /I. *.cpp /link /out:example.exe ws2_32.lib advapi32.lib

Qt Creator

A new Qt Creator project for the example_project/ folder can be created by clicking:

  • File
  • New File or Project...
  • Choose Other Project
  • Choose Empty Qt Project
  • Click Choose...
  • Choose "example_project" as Name
  • Choose the folder that contains the example_project/ folder for "Create in"
  • Click Next
  • Click Next
  • Click Finish

Qt Creator should now show an empty file named example_project.pro. Copy and paste the following lines into it and save the result:

TEMPLATE = app
CONFIG += console
TARGET = example_configuration
win32:LIBS += -lws2_32 -ladvapi32
unix:QMAKE_CXXFLAGS += -pthread
SOURCES += ip_connection.c brick_stepper.c example_configuration.c
HEADERS += ip_connection.h brick_stepper.h

This tells Qt Creator that this is an console application named "example_configuration". It is linked to the ws2_32 and advapi32 libraries on Windows and uses pthreads on Unix (Linux, Mac OS X, etc).

Before stating the program you need to tick the "Run in terminal" check box on the project's run configuration tab, otherwise its output will not be visible.

Now the program can be compiled and started!

This is an example for a project in C. If you want to use the bindings in a C++ project then the simplest way to do this is to rename the required source files from *.c to *.cpp and to change the SOURCES line in example_project.pro accordingly. Then the compiler will treat the source code as C++ and does the right thing automatically.

If you want to add the C/C++ bindings to an existing Qt Creator project then you just need to add the required source files to the SOURCES and HEADERS variables and add these two lines to your .pro file:

win32:LIBS += -lws2_32 -ladvapi32
unix:QMAKE_CXXFLAGS += -pthread

Orwell Dev-C++

A new Dev-C++ project for the example_project/ folder can be created by clicking:

  • File
  • New
  • Project...
  • Choose Console Application and C Project
  • Click Ok

Dev-C++ will now create a new files named main.c. We don't need it, remove it by clicking on "Remove file" in its context menu in the project view. Now add all files from the example_project/ folder to the project by clicking on "Add to Project" in the project's context menu.

Then libws2_32.a (WinSock2) and libadvapi32.a have to included by clicking:

  • Project
  • Project Options
  • Parameters
  • Click Add Library or Object
  • Choose libws2_32.a and libadvapi32.a
  • Click Open
  • Click Ok

Now the program can be compiled and started!

This is an example for a project in C. If you want to use the bindings in a C++ project then the simplest way to do this is to rename the required source files from *.c to *.cpp. Then the compiler will treat the source code as C++ and does the right thing automatically.

API Reference and Examples

Links to the API reference for the IP Connection, Bricks and Bricklets as well as the examples from the ZIP file of the bindings are listed in the following table. Further project descriptions can be found in the Starter Kits section.

  API Examples
IP Connection API Examples
     
Bricks    
DC API Examples
IMU API Examples
IMU 2.0 API Examples
Master API Examples
RED API Examples
Servo API Examples
Stepper API Examples
     
Bricklets    
Accelerometer API Examples
Ambient Light API Examples
Ambient Light 2.0 API Examples
Analog In API Examples
Analog In 2.0 API Examples
Analog Out API Examples
Analog Out 2.0 API Examples
Barometer API Examples
CAN API Examples
CO2 API Examples
Color API Examples
Current12 API Examples
Current25 API Examples
Distance IR API Examples
Distance US API Examples
Dual Button API Examples
Dual Relay API Examples
Dust Detector API Examples
GPS API Examples
Hall Effect API Examples
Humidity API Examples
Industrial Analog Out API Examples
Industrial Digital In 4 API Examples
Industrial Digital Out 4 API Examples
Industrial Dual 0-20mA API Examples
Industrial Dual Analog In API Examples
Industrial Quad Relay API Examples
IO-16 API Examples
IO-4 API Examples
Joystick API Examples
Laser Range Finder API Examples
LCD 16x2 API Examples
LCD 20x4 API Examples
LED Strip API Examples
Line API Examples
Linear Poti API Examples
Load Cell API Examples
Moisture API Examples
Motion Detector API Examples
Multi Touch API Examples
NFC/RFID API Examples
OLED 128x64 API Examples
OLED 64x48 API Examples
Piezo Buzzer API Examples
Piezo Speaker API Examples
PTC API Examples
Real-Time Clock API Examples
Remote Switch API Examples
RGB LED API Examples
Rotary Encoder API Examples
Rotary Poti API Examples
RS232 API Examples
Segment Display 4x7 API Examples
Solid State Relay API Examples
Sound Intensity API Examples
Temperature API Examples
Temperature IR API Examples
Thermocouple API Examples
Tilt API Examples
UV Light API Examples
Voltage API Examples
Voltage/Current API Examples