//Panos Papazoglou, MICRODEV.GR
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64 
#define OLED_DC     8
#define OLED_CS     10
#define OLED_RESET  9
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT,
  &SPI, OLED_DC, OLED_RESET, OLED_CS);

String labels[]={"60", "50", "40","30", "20", "10","0"};

int rad=55; int rr=5;
void setup() 
{
  Serial.begin(9600);
 
  if(!oled.begin(SSD1306_SWITCHCAPVCC)) {
    Serial.println(F("SSD1306 Error"));
    for(;;);
  }

oled.clearDisplay();
oled.display();

draw_circle(63,63,rad-3,6.28,3.14,-0.02);
draw_dots(63,63,rad-3,6.28,3.14,-0.5);
draw_labels(63,63,rad+9,6.28,3.14,-0.5);


}

void loop() {

float a=analogRead(0);
float topx=map(a,0,1023,314,628);
topx=topx/100;

oled.drawLine(63,63,63+(rad-rr)*cos(topx), 63+(rad-rr)*sin(topx),WHITE);
oled.display();

delay(200);
oled.drawLine(63,63,63+(rad-rr)*cos(topx), 63+(rad-rr)*sin(topx),BLACK);
oled.display();
}


void draw_circle(int x, int y, int rad, float from, float to, float step)
{
for(float i=from;i>=to;i+=step)
  {
  float xx=x+rad*cos(i); float yy=y+rad*sin(i);
  oled.drawPixel(xx, yy,WHITE);
  oled.display();
  }
}

void draw_dots(int x, int y, int rad, float from, float to, float step)
{
for(float i=from;i>=to;i+=step)
  {
  float xx=x+rad*cos(i); float yy=y+rad*sin(i);
  oled.fillCircle(xx,yy,2,WHITE);
  oled.display();
  }
}

void draw_labels(int x, int y, int rad, float from, float to, float step)
{
  int lab=0;
for(float i=from;i>=to;i+=step)
  {
  float xx=x+rad*cos(i); float yy=y+rad*sin(i);
  mytext(labels[lab],1,xx-5,yy);
  lab++;
  oled.display();
  }
}


void mytext(String text, int textsize, int x, int y)
{
oled.setTextSize(textsize);
oled.setTextColor(WHITE);
oled.setCursor(x,y);
oled.print(text);
oled.display();
}