An Ironclad Premise

I've been busy lately with the library that I'm hoping will form the foundation of my work with Arduino. It is titled 'Iron', and offers various interfaces for physical computing tasks. The library is based around the concept of devices, encouraging the designer to build code in a fashion that mirrors the physical unit they are creating.

There is a strong theme of performance to the code and, where possible, the lowest-level interfaces are used. For example, direct port manipulation is accomplished with template meta-programming, allowing comfortable labels to be used in place of bit shifts:

// Set pin mode as output. Equivalent to: 'DDRB |= ( 1 << 5 );'
//
setMode< 13, OUTPUT >();

// Set pin 13 high. Equivalent to: 'PORTB |= ( 1 << 5 );'
//
setDigital< 13, HIGH >();

The notion of a device is a cornerstone of the library, gathering variables, communication and inputs & outputs in one place. For example, a camera device might be defined as:

// Define device
//
EN_DEFINE_DEVICE(
    (( Camera, "Example camera device", 0xB0, 0x7B, 0xA6, 0x43 )
    (( Input,    shutter, digital_t, Low,     2 ))
    (( Input,    zoom,    analog_t,  512,     A0 ))
    (( Internal, model,   uint32_t,  2389221, None ))
    (( Internal, flash,   bool,      true,    None ))
    (( Output,   led,     digital_t, Low,     13 ))
)


Devices are designed to be interacted with from either the CPU or the MCU. Following is an example of how a camera's shutter might be expressed with Arduino:

// Create device, with MCU view
//
Camera< MCU > g_cam;

void setup()
{
    // Set up pin modes for any mapped attributes
    //
    g_cam.setup()
}

void loop()
{
    // If shutter button is 'HIGH', begin read of image data
    //
    if ( g_cam.is< 0, HIGH >() )
    {
        g_cam.read< Image >( buffer );
    }
}


From the CPU side it is possible to scan a bus for devices, establishing connections where required:

std::vector< Camera< CPU > > devices = scan< Camera >();

for ( auto it = devices.begin(); it != devices.end(); ++it )
{
    select( *it );   // Select a device. Ready for signals, etc.
    deselect( *it ); // Deselect a device.
}


There are many more facets yet to explore in the library, but it felt right to release it now. It is licensed under the GPL: you are free to use it as-is, or hack it to pieces as you see fit :) Enjoy!

https://github.com/engine-develop/iron