mraa Documentation

Library in C/C++ to interface with Galileo & other Intel platforms, in a structured and sane API with port names/numbering that match boards & with bindings to javascript & python.

The intent is to make it easier for developers and sensor manufacturers to map their sensors & actuators on top of supported hardware and to allow control of low level communication protocol by high level languages & constructs.

API

These interfaces allow you to interact with all libmraa functionality. The C++ classes directly wrap the C API and provide a near 1:1 mapping of functionality.

C API Modules	C++ API Classes
gpio	Gpio class
i2c	I2c class
aio	Aio class
pwm	Pwm class
spi	Spi class
uart	Uart class
common	common

Hello Mraa

#include "mraa.h"

int
main(int argc, char **argv)
{
    fprintf(stdout, "hello mraa\n Version: %s\n", mraa_get_version());
    mraa_deinit();
    return 0;
}

Supported platforms

Specific platform information for supported platforms is documented here:

• Galileo Gen 1 - Rev D
• Galileo Gen 2 - Rev H

ENV RECOMENDATIONS

All of these are 'optional', however they are recommended. Only a C compiler, cmake, libm and pthreads are technically required to compile.

• Swig 3.0.1+ built with node.js & python support (0.10.x)
• doxygen
• sphinx (requires doxygen)
• pygments

COMPILING

More information on compiling is Building libmraa page

CONTRIBUTING

Please see the Contributing to libmraa page

API Changelog

This changelog is meant as a quick & rough guide to what has changed between versions. The API is now fairly stable but when new calls/features are added they are listed here. Anything pre 0.2.x is ignored.

0.4.5

• if only one spidev we default to it reguardless of number
• mraa_pwm_config_ms & mraa_pwm_config_percent functions added
• Uart C++ class added, adds python & node support
• galileo gen2 gpio modes supported

0.4.4

• prefix SPI mode with MRAA_SPI_
• added C++ adc bitness calls

0.4.3

• SPI Mode function now functional, API Change in SPI
• I2C read in swig worked on.
• Galileo Gen 2: PWM setting period sets all channel's period
• Galileo Gen 2: I2C setup now specific to Gen 2.
• General commits around freeing memory at the right times.

0.4.2

• Barebone UART module added.
• Hook branch merged.
• I2C init hooks added.
• Intel Galileo Gen 2, I2C gpio pins now go hiz input when I2C initialised.

0.4.1

• Rename python & nodejs modules to mraa
• common.hpp introduced for C++
• python & nodejs modules can now take binary strings for Spi & I2c
• improved Aio module and clear bitness
• Improved Galileo Gen 2 support

0.4.0

• Rename to mraa
• get_platform_type function added.

0.3.1

• Initial Intel Galileo Gen 2 support
• mraa_gpio_isr parameters added.
• Detection of different supported platforms added.

0.3.0

• mraa_i2c_read now returns length of read

0.2.9

• Add global mraa.h & mraa.hpp headers
• usage of "gpio.h" is not legal you need to use "mraa/gpio.h" unless adding -L/usr/include/mraa

0.2.8

• Added mraa_set_priority call
• Added mmap gpio call mraa_gpio_use_mmaped

0.2.7

• C++ API now uses basic types and not unistd types as C
• Clearer and consistent use of unistd tpyes in C api

0.2.6

• C++ examples added, using c++ headers/api.
• moved to open instead of fopen in all modules
• rename mraa_check functions and made them internal to mraa only.
• removed "export" functions from api
• Intel Galileo Gen 1 (rev d) fixes, incorrect definition of some items
• SPI, implementation completed.
• I2C internal function, completed.
• PWM fix bug in period set method.
• Swig upstream can be used for building.
• No longer builds docs on default cmake, needs flag
• GPIO/PWM ownership guard prevents closing on existing pins, still can be forced.

0.2.5

• C++/Python/Node Enums/const names now do not contain MRAA_GPIO
• Enum type declaration for C++ changed
• Python/Node get_version() -> GetVersion()
• i2c read calls don't use const char* and i2c write calls do

0.2.4

• All mraa_ contexts now are pointers to the actual struct which is not delcared in the header. The only end user change is that instead of returning a type mraa_gpio_context pointer mraa_gpio_init() now returns a mraa_gpio_context (which is actually a pointer to struct _gpio internally).
• C++ API is available, use the .hpp headers and add stdc++ to the linker flags.
• Initial SPI implementation is provided

0.2.3

• mraa_aio_read_u16() -> mraa_aio_read()
• mraa_aio_read() now returns a uint16_t instead of an unsigned int

0.2.2

• First version with API considered 'stable'