/* Raw Dawg'n the Arduino
	
      Lesson 0
        Tools and Software
          Download and install Atmel Studio 7
          web installer http://studio.download.atmel.com/7.0.2397/as-installer-7.0.2397-web.exe
          offline installer http://studio.download.atmel.com/7.0.2397/as-installer-7.0.2397-full.exe
    
          Download and install (unzip) avrdude
          https://sourceforge.net/projects/avrdudegui/files/latest/download
          
          I'm assuming you have the Arduino IDE already installed. You will need two Arduinos. One you will be your ISP 
          (In System Programmer). The other will be the one you are working/playing with. The Arduino IDE includes a sketch called 
          ArduinoISP (File -> Examples -> ArduinoISP). Upload this sketch to one of the Arduino's. This will be the ISP, i.e what 
          you use to program the other Arduino.
    
          Open Atmel studio and select new project (File -> New -> Project). Select GCC C Executable Project from the popup window.
          Name the project Lesson0 and click OK. Select the microcontoller that is installed in your Arduino. ATMEGA2560 for the mega
          or ATMEGA328P for the UNO. Click OK. This creates a file called main.c It will already have some stuff in it. replace it 
          with the following: */
    
          #include <avr/io.h>     	// this file contains all the human readable names for the registers/ports
          #include <util/delay.h>	  // this is the header file for the _delay_ms() function
    

          // all c programs must include the main() function
          int main(){				
          
          /* DDRD Data Direction Register PORTD setting the bits to 1 makes the corresponding pins an output. 
           Setting to 0 makes them 
           an input. 0xFF = 0b11111111, we are setting all 8 pins on PORTD as output. You can connect and LED to any pin on PORTD 
           and watch it blink. DON'T FORGET THE CURRENT LIMIT RESISTOR */
           
          DDRD = 0xFF;  

          while(1){			
            PORTD = 0xFF;	   
            _delay_ms(250);	   
            PORTD = 0x00;	   
            _delay_ms(250);	  
           }					
          }
          /* while(1): while evaluates an the expression inside of (). If true (ie not 0) the while loop will execute. If false (0) 
           the while loop will not execute. Microcontrollers typically perform the same tasks over and over and never terminate
           from the main loop. Since the expression (1) will never be 0 or false this while loop will always get executed. This is
           equilivant to the Loop() in the Arduino sketches.
           writing a 1 to an output port puts the voltage high, writing a 0 pulls the voltage low. */

          /* Select Project -> Lesson0a Properties. This will bring up Properties. Change Configuration from debug to release. You 
          will now have to tell the compliler the CPU frequency. The Arduino has a 16 MHz clock. Select Toolchain from the left hand
          side and then click symbols from the middle column. Click on the '+' icon on the right hand side of Define symbols (-D) 
          and type "F_CPU=16000000UL" in the pop up. Click OK. Save main.c. Now build the
          project. Build -> Build Solution.
    
          The build process should create a file called main.hex. This is the file you will upload into the Arduino. Open up AVRDUDE.
          Select ATMEGA2560 as the target device. Select Lesson0a.hex for the FLASH file. It is probably located at:
          Documents -> Atmel Studio -> 7.0 -> Lesson0a -> Lesson0a -> Release -> Lesson0a.hex.
    
          The Arduino web site shows how to physically connecto the ISP to the Arduino. https://www.arduino.cc/en/Tutorial/ArduinoISP.