/*
  Zeitgeist-o-meter

  A scrolling Twitter display for Arduino
  For more see: 
    http://www.instructables.com/id/Arduino-LCD-Twitter-display

  Copyright PKM 2010

*/

/*
  LiquidCrystal Library
  
 Library originally added 18 Apr 2008
 by David A. Mellis
 library modified 5 Jul 2009
 by Limor Fried (http://www.ladyada.net)
 example added 9 Jul 2009
 by Tom Igoe
 modified 8 Feb 2010
 by Tom Igoe
 
 This example code is in the public domain.

 http://www.arduino.cc/en/Tutorial/LiquidCrystal  
 
  The circuit:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)
 
 */

// include the library code:
#include <LiquidCrystal.h>
#include <Servo.h> 

#define USART_RX_BUFFER_SIZE  (150)
 
Servo myservo;  // create servo object to control a servo 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
    // lcd.print for text constants/strings
    // lcd.write for variables
    
long loop_start;
int bytei; // used in writing serial data to string
int col; // used to print a row's worth of string to lcd
int input_pin = 0;
int new_tweet_status = 0; // only move the flag once
int servo_switch_pin = 7; // pin for servo power transistor
int servo_pin = 9; // pin for servo control signal
int sensor_delay; // read from analog pin, transform to delay in ms
char inmsg[200];
int servo_tick = 10;


void setup() {
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.clear();
  lcd.noAutoscroll();  
  lcd.setCursor(0,0);
  lcd.print("Zeitgeistometer!");
  lcd.setCursor(0,1);
  lcd.print(" (c) PKM 2010");
  
  myservo.attach(servo_pin);  // attaches the servo on pin 9 to the servo object 
  pinMode(servo_switch_pin, OUTPUT);
  digitalWrite(servo_switch_pin, HIGH);
  myservo.write(0);
  delay(250);  
  digitalWrite(servo_switch_pin, LOW);  
  Serial.begin(9600);
  delay(5000); // time to start up host script
}

void loop()
{
  loop_start = millis();
  // test modularised status check
  Serial.print("status\n");
  while (Serial.available() == 0 && (millis() < loop_start+10000)) {}
  if (Serial.available()) {
    delay(100); // wait for entire status message
    
    // read message into buffer
    read_to_buffer();
    
    // clear bottom
    // clear_row(1);
    
    // write status message
    lcd.setCursor(0,1);
    
    // for (bytei = 1;bytei < 17; bytei++) {
    //   if (inmsg[bytei] == '\0') { 
    //     lcd.write(' ');
    //   } else {
    //     lcd.write(inmsg[bytei]);
    //   }
    // }
    
    if (inmsg[0] == 'T') {
      if (new_tweet_status == 0) {
        new_tweet_status = 1;
        // myservo.write(0);
        digitalWrite(servo_switch_pin, HIGH);
        for (bytei=0; bytei < 101; bytei++) {
          myservo.write(bytei);
          delay(10);
        }
        delay(50);
      }
      
      digitalWrite(servo_switch_pin, LOW);
      lcd.print("   ");
      for (bytei=1 ; bytei<14 ; bytei++) {
        if (inmsg[bytei] != '\0') { 
          lcd.write(inmsg[bytei]);
        } else {
          lcd.print(' ');
        }
      } // next bytei
    } else {
      if (new_tweet_status == 1) {
        new_tweet_status = 0;      
        // myservo.write(90);      
        digitalWrite(servo_switch_pin, HIGH);      
        for (bytei=100; bytei >=0; bytei--) {
          myservo.write(bytei);
          delay(15);
        }
        delay(50);
        digitalWrite(servo_switch_pin, LOW);      
      }
      lcd.print(" #instructables ");
    }
      
  } else {
    lcd.setCursor(0,0);
    lcd.print(" No status mesg ");
    lcd.setCursor(0,1);
    lcd.print("       :(       ");
    // no serial available
  }
  
  delay(500);
  
  
  // test modularised tweet check
  Serial.print("tweet\n");
  while (Serial.available() == 0 && (millis() < loop_start+8000)) {}
  if (Serial.available()) {
    delay(150); // wait for entire message
    
    // read message into buffer
    read_to_buffer();
  
    // clear top row
    clear_row(0); 
    
    // set marker to beginning of tweet
    bytei=0;
       
    while (inmsg[bytei+15] != '\0') {
      // scrolly scrolly 
      
      sensor_delay = analogRead(input_pin); 
      sensor_delay = 1024-sensor_delay;
      sensor_delay = sensor_delay/2;
      sensor_delay += 50; // (scaled to range 100-300)   
      // sensor_delay = 150; 
      lcd.setCursor(0,0);
      for (col = 0; col < 16; col++) {
        lcd.write(inmsg[bytei + col]);
      }
  
      // sdelay(millis() + sensor_delay);
      bytei++;
      delay(sensor_delay);
    // } 
    }  
  } else {
    lcd.setCursor(0,1);
    lcd.print("No twit response");
    // no serial available
  }
}

void clear_buffer()
{
  for (bytei=0;bytei<150;bytei++) {
    inmsg[bytei] = '\0';
  }
}

void read_to_buffer()
{
  clear_buffer();
  bytei = 0;
  while (Serial.available() > 0) {
    inmsg[bytei] = Serial.read();
    bytei++;
  }
  if (bytei == 127 || bytei == 128)
  while (Serial.available() > 0) {
    inmsg[bytei] = Serial.read();
    bytei++;
  }
  
  bytei = 0;
}  

void clear_row(int r)
{
  lcd.setCursor(0,r);
  lcd.print("               ");
  lcd.setCursor(0,r);
}