1 Porting a module from Arduino {#porting} 2 ============================= 3 4 Porting arduino libraries to libmraa as UPM libraries is usually fairly easy. 5 The issues typically come from misunderstanding of how a non real time OS deals 6 with interrupts and timers. It also highly depends on the sensor. A concrete 7 example is explained in detail on @ref max31855 8 9 ### Adding a new module to UPM 10 11 1. Choose a name for your module (see @ref naming) 12 2. Make a new folder in src/modulename 13 3. Create a CMakeLists.txt file inside src/modulename 14 15 ### CmakeLists.txt 16 17 By default you need a header called modulename.h and a C++ file called 18 modulename.cxx. You can have multiple headers and source files. Only public 19 headers need to be added to module_h and all source files need to be in 20 module_src. 21 22 ~~~~~~~~~~~ 23 set (libname "modulename") 24 set (libdescription "Module Description") 25 set (module_src ${libname}.cxx) 26 set (module_h ${libname}.h) 27 upm_module_init() 28 ~~~~~~~~~~~ 29 30 ### Making your API 31 32 The easiest way to do this is to have a look at a similar sensor to yours. 33 Typically create a class for your sensor with a constructor that defines the 34 pins it is on. This constructor will create the mraa_*_context structs that are 35 required to talk to the board's IO. An I2c sensor will create a 36 mraa_i2c_context, keep it as a private member and require a bus number and slave 37 address in it's constructor. 38 39 Typically in sensors a simple object->read() function is preferred, depending on 40 your sensor/actuator this may or may not be easy or not even make sense. Most 41 UPM APIs have a simple set of functions. 42 43 ### Mapping arduino API to libmraa 44 45 Your constructor is similar to the setup() function in arduino, you should 46 initialise your IO the way you want it. This means initialising contexts 47 (private members) and setting the correct modes for them. 48 49 See the mraa API documentation for exact API. 50 51 ### Building 52 53 To build your module just follow @ref building. By creating a folder and the 54 CMakelists.txt file you have done all that is required to add your sensor to 55 the UPM build system. 56 57 ### Sending your module to us for inclusion in UPM 58 59 The last step is when you're happy with your module and it works send us a pull 60 request! We'd love to include your sensor in our repository. 61 62 If you don't like github you can also send mihai.tudor.panu (a] intel.com a git 63 formatted patch of your sensor. More details are on @ref contributions and on 64 https://help.github.com/articles/creating-a-pull-request 65 66
