Arduino Core for mbed enabled devices

This repo contains an implementation of Arduino style classes and methods but using mbed OS underneath. This is something very similar to what we are trying to do with Zephyr.

UART/ Serial Implementation

• Inside Arduino.h there is a #define that leads to an object _UART1_ inside Serial.h.

• Here, we can see from extern arduino::UART _UART1_; that the object is of class UART which is defined just above.

• The implementations of the functions inside this class are then found in Serial.cpp.

Similar structure can be followed for this project by simply replacing the implementations of all the functions with zephyr style functions.

I2C Implementation

There is a file in the arduino API, HardwareI2C.h which contains the virtual prototypes of all the methods related to IIC. However as the class HardwareI2C is virtual we can not implement these methods as a part of this class and hence will need our own library / class definition that inherits from this virtual base class .

To demostrate what I mean above in the form of pseudo code,

We have api/HardwareI2C.h that has the contents:

class HardwareI2C : public Stream
{
    public:
        virtual void begin() = 0;
        virtual void beginTransmission(uint8_t address) = 0;
        .
        .
        .   // other IIC methods
}

Now, inorder to implement all the above methods, we can then create our own class like in the case of mbed, they have libraries/Wire

class MbedI2C : public HardwareI2C

where the custom class MbedI2C inherits these method names from the arduino api. These functions and then implemented inside Wire.cpp.

Inorder to access all these functions, we have the object called Wire which is standard and used in many arduino libraries, using extern arduino::MbedI2C Wire; inside Wire.h.