/*************************************************************************************************
                                      PROGRAMMINFO
**************************************************************************************************
Funktion: Analogwertanzeige auf OLED 0,96" mit Poti
Poti A3 Shield=IO34 Bei 3,3V Anzeige nur bis 90MHP!
**************************************************************************************************
Version: 226.12.022
**************************************************************************************************
Board: UNO OLED 1.3" oder 0,96"
**************************************************************************************************
Libraries:
https://github.com/espressif/arduino-esp32/tree/master/libraries
C:\Users\User\Documents\Arduino
D:\gittemp\Arduino II\A156_Wetterdaten_V3
**************************************************************************************************
C++ Arduino IDE V1.8.19

**************************************************************************************************
Einstellungen:
https://dl.espressif.com/dl/package_esp32_index.json
http://dan.drown.org/stm32duino/package_STM32duino_index.json
http://arduino.esp8266.com/stable/package_esp8266com_index.json
**************************************************************************************************/
#include "U8glib.h"
U8GLIB_SH1106_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST);    //OLED 1,3"
//U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST); // OLED 0,96"

int xmax=128;                                   // max length x-axis
int ymax=62;                                    // max length y-axis
int xcenter=xmax/2;                             // center of x-axis
int ycenter=ymax/2+10;                          // center of y-axis
int arc=ymax/2;                              
int angle=0;                                    
char* label[] = {"LOAD","Temperatur","INTAKE", "VOLT"};    // some custom gauge labels
int labelXpos[] = {53, 39, 49, 53};                     // predefined x-position of a gauge label
#define potmeterPin A3                                  // simulate analogue value with potentiometer
int p, w, m;
u8g_uint_t xx=0;

// ------------------------------------------------- void gauge() ------------------------------------------
void gauge(uint8_t angle) {

  // draw border of the gauge
  u8g.drawCircle(xcenter,ycenter,arc+6, U8G_DRAW_UPPER_RIGHT);
  u8g.drawCircle(xcenter,ycenter,arc+4, U8G_DRAW_UPPER_RIGHT);
  u8g.drawCircle(xcenter,ycenter,arc+6, U8G_DRAW_UPPER_LEFT);
  u8g.drawCircle(xcenter,ycenter,arc+4, U8G_DRAW_UPPER_LEFT);

  // draw the needle
  float x1=sin(2*angle*2*3.14/360);              // needle position
  float y1=cos(2*angle*2*3.14/360);  
  u8g.drawLine(xcenter, ycenter, xcenter+arc*x1, ycenter-arc*y1);
  u8g.drawDisc(xcenter, ycenter, 5, U8G_DRAW_UPPER_LEFT);
  u8g.drawDisc(xcenter, ycenter, 5, U8G_DRAW_UPPER_RIGHT);
  u8g.setFont(u8g_font_chikita);
  
  // show scale labels
  u8g.drawStr( 20, 42, "0");                    
  u8g.drawStr( 25, 18, "15");
  u8g.drawStr( 60, 14, "30");
  u8g.drawStr( 95, 18, "45");
  u8g.drawStr( 105, 42, "60");
  
  // show gauge label
  u8g.setPrintPos(labelXpos[1],32);             
  u8g.print(label[1]);
  
  // show digital value and align its position
  u8g.setFont(u8g_font_profont22);              
  u8g.setPrintPos(54,60);
  if (w<10){                                    // leading 0 when value less than 10
    u8g.print("0");
  }
  if (w>99) {                                   // position at 100%
    u8g.setPrintPos(47,60);
  }
  u8g.print(w);
}

// ------------------------------------------------- void setup() ------------------------------------------
void setup(void) {
  pinMode(potmeterPin, INPUT);
  u8g.setFont(u8g_font_chikita);
  u8g.setColorIndex(1);                         // Instructs the display to draw with a pixel on. 

  // assign default color value
  if ( u8g.getMode() == U8G_MODE_R3G3B2 ) {
    u8g.setColorIndex(255);                     // white
  }
  else if ( u8g.getMode() == U8G_MODE_GRAY2BIT ) {
    u8g.setColorIndex(3);                       // max intensity
  }
  else if ( u8g.getMode() == U8G_MODE_BW ) {
    u8g.setColorIndex(1);                       // pixel on
  }
  else if ( u8g.getMode() == U8G_MODE_HICOLOR ) {
    u8g.setHiColorByRGB(255,255,255);
  }
}

// ------------------------------------------------- void loop() ------------------------------------------

void loop(void) {

  
  p = analogRead(potmeterPin);                  // get value from potmeter
  w = map(p,0,1023,0,60);                      // map it between 0 and 100
  m = map(p,0,1023,0,90);                       // map needle movement

  // show needle and dial
  xx = m;                                      // 135 = zero position, 180 = just before middle, 0 = middle, 45 = max
  if (xx<45){                                   // positie correctie
    xx=xx+135;
  }
  else {
    xx=xx-45;
  }
  
  // picture loop
  {
    u8g.firstPage();  
    do {              
      gauge(xx); 
    } 
    while( u8g.nextPage() ); 
  }
}