/*
    Example that blinks a LED on a Raspberry Pi using my GPIOCPP class.
    GPIOCPP version 0.09, march 18, 2017 COPYLEFT - Pieter Suurmond.

    To compile this example with GCC, use the '-std=c++11' option. For example:
        g++ -Wall -O2 -std=c++11 blink.cpp gpiocpp.cpp -o blink
    But you may also use the supplied Makefile: just type 'make'.

    Before running this blink executable, connect a LED, with series resistor!,
    from GPIO pin 27 to GND. Make sure the correct pin number and the correct
    Pi model number are specified below! Run with './blink' and watch for tiny
    glitches, short flashes, especially during the last phase (at 1000 Hz).
    These are possibly due to interrupts by other processes running on the Pi.
*/
#include <iostream>                                 // For cout.
#include <unistd.h>                                 // For usleep().
#include "gpiocpp.h"                                // Our GPIOCPP class.

int main()
{
    const char ledpin = 27;     // Broadcom GPIO27 as output pin. Using const or
                                // constexpr here compiles to faster code!
    try {
        // First argument is Pi model number: 1 (for ARMv6) or 2 (for ARMv7).
        // Second argument is pathname to mem-map: "/dev/mem" or "/dev/gpiomem".
        GPIOCPP gpio(2, "/dev/gpiomem");

        gpio.config_write(ledpin);                  // Configure as output pin.

        std::cout << "Blink LED on GPIO" << (int)ledpin << " 4 times.\n";
        for (int t = 0; t < 4; t++) {
            usleep(500000);                             // 500 milliseconds.
            gpio.setpin(ledpin);                        // LED on.
            usleep(500000);
            gpio.clearpin(ledpin);                      // LED off.
        }
        std::cout << "Now approximately 10 Hz, for 4 seconds.\n";
        for (int t = 0; t < 40; t++) {
            usleep(50000);                              // 50 milliseconds.
            gpio.setpin(ledpin);
            usleep(50000);
            gpio.clearpin(ledpin);
        }
        std::cout << "Now 100 Hz, for 4 seconds.\n";
        for (int t = 0; t < 400; t++) {
            usleep(5000);                               // 5 milliseconds.
            gpio.setpin(ledpin);
            usleep(5000);
            gpio.clearpin(ledpin);
        }
        std::cout << "Finally 1000 Hz, duty cycle=10%.\n";
        for (int t = 0; t < 4000; t++) {
            usleep(900);                                // 500 microseconds.
            gpio.setpin(ledpin);
            usleep(100);
            gpio.clearpin(ledpin);
        }
    }
    catch (const char* errtxt) {    // When something goes wrong the constructor
        std::cout << errtxt;        // throws an exception describing the error.
        return 1;
    }
    std::cout << "Done.\n";
    return 0;
}