Linux Userspace GPIO Library

• Export and Unexport GPIO pins
• Interrupt support (*)
• Hardware-neutral rewrite of NoccyLabs RaspIO
• Compatible with psr/logs LoggerInterface for logging

Interrupts

NOTE: Not implemented!

For interrupts to work, you need to first bind the interrupt handler, and then make sure to call on Gpio#refresh() every cycle to poll the interrupt flag on the selected pins. This is because the select() function is used.

$gpio = new Gpio();

// Set the handler on the Gpio object
$gpio->setInterruptHandler($gpio[4], function() { ... });
// Or like this on the GpioPin.
$gpio[4]
    ->setEdge("rising")
    ->setHandler(function() { ... });

while (..) {
    ..
    $gpio->refresh();
}

You can also be risky and use php ticks and timerfuncs (although that might not be portable/supported/efficient/a good idea):

declare(ticks=5);

$gpio = new Gpio();

$gpiotick = new GpioTickHandler();
$gpiotick->registerGpio($gpio);

// The interrupts will now be polled approx every 5th php vm "tick"

Devices

$lcd = new NoccyLabs\Gpio\Device\Display\Pcd8544Device;
// Set I/O pins
$lcd->res = $gpio[4];
$lcd->dc  = $gpio[8];
...
// Activate the device
$lcd->activate();
// Clear and draw text
$lcd->clear();
$lcd->writeAt(0,0,"Hello World");
echo $lcd->getRows(); // 5
echo $lcd->getCols(); // 19

LCD Bridge

The LCD bridge will be able to bridge any device class implementing LcdDeviceInterface to stdin or a named pipe. This basically creates a user-space daemon to interface with the display without having to fiddle with bits.

$ lcdbridge -t pcd8544 --stdin
CLR
LOC 0 0
FONT 0
OUT Hello World
^C
$ 

Commands should include:

• CLR clears the display (LcdDeviceInterface#clear())
• LOC n m moves the cursor to line n column m (0-indexed) (LcdDeviceInterface#setCursorPos(n,m))
• FONT n loads the default font (0) or a custom font file (LcdDeviceInterface#setFont())
• OUT Write text to the display (LcdDeviceInterface#write())