/*
         RoboShutta
         
   Version 1
   For Arduino Trinket by Adafruit
   
Code for controlling a servo-driven shutter on a pinhole camera via a cable
from a distance.  Simplicity and reliability are paramount.  Such a remote /
automatically controlled shutter-equiped camers, mounted on GoPro (or similar) 
hardware shall be collectively termed a GoSlo camera system.

Lacking proper PWM output, a clever hack is utilized to update the
position of the servo arm via an interupt.  This should have minimal
impact on functionality, but similar code could be easily written
for other Arduino (semi-) ompatibles.

Suitable camera applications are:
		http://www.thingiverse.com/thing:577223
		http://www.thingiverse.com/thing:495230

Servo-ready parts for these cameras are pending on Thingiverse.com
        

    created  02/21/2015
   by Todd Schlemmer theschlem@gmail.com
   
   SOURCES:
   Adapted from TrinketKnob/SoftServo by Adafruit
   
   RESOURCES:
      https://learn.adafruit.com/downloads/pdf/introducing-trinket.pdf
      https://learn.adafruit.com/trinket-gemma-servo-control/overview
      http://www.akeric.com/blog/?tag=arduino
      

This sketch allows for remote control of a servo-driven pinhole camera shutter.

    Required library is the Adafruit_SoftServo library
    available at https://github.com/adafruit/Adafruit_SoftServo
    The standard Arduino IDE servo library will not work with 8 bit
    AVR microcontrollers like Trinket and Gemma due to differences
    in available timer hardware and programming. We simply refresh
    by piggy-backing on the timer0 millis() counter

    All circuitry is housed in a case with the 6-12V battery pack, and connected to the 
    shutter servo via a standard 3-wire servo cable(s).  Servos can be controlled by 
    connecting mutiple cables, many meters in length.  
    
    Handheld remote 
      power switch
      safety switch -momentary (unable to open shutter if not depressed)
      shutter switch -toggle
      status LED tied to PIN1, used for status, debugging, error purposes
  
 CIRCUITRY:  

******** diagrams and pinouts ***********************
          
                         Trinket Arduino Compatible
                                By Adafruit
            
                                MINI USB
                                ________
                          _____|        |_____
                         |  _  | ||  || |  _  |
                         | (_) | ||  || | (_) |
                         |  _  | ====== |  _  |
            Green LED    | [G] |________| [R] |   red status LED
            (power)      |                    |
                  BAT +  | O  [] [] []  ||  O |   USB 5V+
                         |              ||    |
                  GND -  | O   =[]=  []     O |   #0               SERVOPIN
                         |     =[]=           |
                  #4     | O                O |   #1  (red LED)    LEDPIN
                         |     _u_u_u_        |
   SAFETYPIN      #3     | O  |       |     O |   #2               SHUTTAPIN
                         |    |       |       |
                  RESET  | O  |_______|     O |   5 V+ (regulated from BAT)
                         |  _   n n n      _  |
                         | (_)  |    |    (_) |
                         |_     |_[]_|   _____| 
                           \____________/                    
                             Reset switch
               
               
               Servo Plug
               
                _______________
               |   __  _       |
    Ground     |  [__] _]      |==brown wire============
               |   __  _       |
    5V +       |  [__] _]      |==orange wire===========
               |   __  _       |            
    Signal     |  [__] _]      |==yellow wire===========
               |_______________|
 
 
           
 ******** ARDUINO Wiring ***************************************
 
BAT & GND wired to battery pack through power switch
Pin #0 to servo signal
Pin #1 to status LED
Pin #2 from shutta switch (toggle 1=open 0=closed)
Pin #3 from safety switch (momentary)



 

 */

// ***************** Declarations and Initializations ******************* 

   //int VariableName = 2;       //comment

   //#include <Library.h>        // some library module
 
 
#include <Adafruit_SoftServo.h>  // SoftwareServo (works on non PWM pins)
 

#define SERVO1PIN 0   // Servo control line (orange) on Trinket Pin #0

#define LEDPIN 1      // Status LED wired to Pin #1
 
#define SHUTTAPIN 2   // Toggle switch (shutter control) on Trinket Pin #2 (Analog 1)

#define SAFETYPIN 3   // Momentary pushbutton on Trinket Pin #3
 
Adafruit_SoftServo myServo1, myServo2;  //create TWO servo objects

int OpenedValue = 102;      // Servo position for opened shutter, determined experimentally with ShuttaSetup

int ClosedValue = 23;       // Servo position for closed shutter, determined experimentally with ShuttaSetup
         
int servoPos;               // variable for servo position
 
 
  
  
// ************************************************** 

void setup() 
{
  // Set up the interrupt that will refresh the servo for us automagically
  OCR0A = 0xAF;            // any number is OK
  TIMSK |= _BV(OCIE0A);    // Turn on the compare interrupt (below!)
  
  
  pinMode(LEDPIN, OUTPUT);
  pinMode(SHUTTAPIN,INPUT);
  
  
  myServo1.attach(SERVO1PIN);     // Attach the servo to pin 0 on Trinket
    CloseShutta();
    digitalWrite(LEDPIN, HIGH);
    delay(1000);
    digitalWrite(LEDPIN, LOW);

}


// ************************************************** 


void loop()
    {
      Start:  // label used to break out of routine if necessary
      
            
        if (digitalRead(SHUTTAPIN))
            {
              OpenShutta();
            }
            else
            {
              CloseShutta();
            }


    }


// We'll take advantage of the built in millis() timer that goes off
// to keep track of time, and refresh the servo every 20 milliseconds
// The SIGNAL(TIMER0_COMPA_vect) function is the interrupt that will be
// Called by the microcontroller every 2 milliseconds


    volatile uint8_t counter = 0;
    SIGNAL(TIMER0_COMPA_vect) 
    {
          // this gets called every 2 milliseconds
           counter += 1;
          // every 20 milliseconds, refresh the servos!
            if (counter >= 5) 
            {
                     counter = 0;
                     myServo1.refresh();
            }
    }




// subroutine  OpenShutta *******************************

void OpenShutta()
{
          servoPos = OpenedValue;                 
          myServo1.write(servoPos);               // tell servo to go to position
          digitalWrite(LEDPIN, HIGH);
          delay(200);                            // waits 1500ms for the servo to reach the position
}


// subroutine  CloseShutta *******************************

void CloseShutta()
{
          servoPos = ClosedValue;                 
          myServo1.write(servoPos);               // tell servo to go to position
          digitalWrite(LEDPIN, LOW);
          delay(200);                            // waits 1500ms for the servo to reach the position
}


  
/* subroutine LEDdebug *******************************
      Used to demonstrate some small value for debugging purposes
      by flashing Pin1 LED some number of times.
*/

    void LEDdebug(int number)
    {
         for (int i=1; i <= number; i++)
         {
          digitalWrite(LEDPIN, HIGH);
          delay(500);
          digitalWrite(LEDPIN, LOW);
          delay(500);
         }  
    }