Ladedruck V3

#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_GC9A01A.h"
#define TFT_DC 7
#define TFT_CS 10

// Hardware SPI on Feather or other boards
Adafruit_GC9A01A tft(TFT_CS, TFT_DC);

int boostPressure;
int boostMax = 0;
int boostMax1 = 2500;
int boostMin = 0;
int boostMin1 = 0;
int ypos = 128;


unsigned long startMillis;
unsigned long currentMillis;
const unsigned long period = 100;

const int sensorHistoryLength = 128;
int sensorHistory[sensorHistoryLength];
int sensorHistoryPos = sensorHistoryLength - 1;

#define DISPLAY_BACKLIGHT  A9 // Pin for backlight control (-1 for none)
#define BACKLIGHT    1



void display_meter(float scale) {

  float angle  = (PI / 1023) * analogRead(A7);   // map analog in 0,1023, to 0.00,3.14
  int length = 50; // line height Ratio of Screen 0-64


  const byte x0 = 120;                                    // x0 Line Start 0-128
  const byte y0 = 120;                                    // y0 Line Start 0-64

  byte x1 = x0 - length * cos (angle);
  byte y1 = y0 - length * sin (angle);

  tft.drawLine(x0, y0, x1, y1,  GC9A01A_GREEN); // write to screen

}
void Text(float scale) {

  tft.setTextColor(GC9A01A_MAGENTA, GC9A01A_BLACK );
  tft.setCursor(180, 140);
  tft.setTextSize(2);

  char cstr[6];
  dtostrf((float)boostPressure / 100  , 1, 2, cstr);


  tft.print(cstr);
  tft.setCursor(50, 140);
  //tft.print("NOW");

  tft.setCursor(180, 160);

  dtostrf((float)boostMax / 100  , 1, 2, cstr);


  tft.print(cstr);
  //tft.setCursor(50, 80);
  //tft.print("MAX");

}



void setup() {

  //  Serial.begin(9600)
  tft.begin();
  tft.fillScreen(GC9A01A_BLACK);
  startMillis = millis();

  tft.drawLine(119, 20, 119, 40, GC9A01A_GREEN);
  tft.drawLine(120, 20, 120, 40, GC9A01A_GREEN);
  tft.drawLine(121, 20, 121, 40, GC9A01A_GREEN);

  tft.drawLine(20, 119, 40, 119, GC9A01A_GREEN);
  tft.drawLine(20, 120, 40, 120, GC9A01A_GREEN);
  tft.drawLine(20, 121, 40, 121, GC9A01A_GREEN);

  tft.drawLine(119, 220, 119, 200, GC9A01A_GREEN);
  tft.drawLine(120, 220, 120, 200, GC9A01A_GREEN);
  tft.drawLine(121, 220, 121, 200, GC9A01A_GREEN);

  tft.drawLine(200, 119, 220, 119, GC9A01A_GREEN);
  tft.drawLine(200, 120, 220, 120, GC9A01A_GREEN);
  tft.drawLine(200, 121, 220, 121, GC9A01A_GREEN);

  tft.drawLine(80, 189, 70, 206, GC9A01A_GREEN);
  tft.drawLine(80, 190, 70, 207, GC9A01A_GREEN);
  tft.drawLine(80, 191, 70, 208, GC9A01A_GREEN);

  tft.drawLine(34, 169, 51, 159, GC9A01A_GREEN);
  tft.drawLine(34, 170, 51, 160, GC9A01A_GREEN);
  tft.drawLine(34, 171, 51, 161, GC9A01A_GREEN);

  tft.drawLine(34, 69, 51, 79, GC9A01A_GREEN);
  tft.drawLine(34, 70, 51, 80, GC9A01A_GREEN);
  tft.drawLine(34, 71, 51, 81, GC9A01A_GREEN);

  tft.drawLine(70, 33, 80, 50, GC9A01A_GREEN);
  tft.drawLine(70, 34, 80, 51, GC9A01A_GREEN);
  tft.drawLine(70, 35, 80, 52, GC9A01A_GREEN);

  tft.drawLine(160, 50, 170, 33, GC9A01A_GREEN);
  tft.drawLine(160, 51, 170, 34, GC9A01A_GREEN);
  tft.drawLine(160, 52, 170, 35, GC9A01A_GREEN);

  tft.drawLine(189, 79, 207, 69, GC9A01A_GREEN);
  tft.drawLine(189, 80, 207, 70, GC9A01A_GREEN);
  tft.drawLine(189, 81, 207, 71, GC9A01A_GREEN);





  tft.drawLine(94, 216, 97, 207, GC9A01A_YELLOW);
  tft.drawLine(95, 216, 98, 207, GC9A01A_YELLOW);

  tft.drawLine(49, 191, 56, 183, GC9A01A_YELLOW);
  tft.drawLine(50, 191, 57, 184, GC9A01A_YELLOW);

  tft.drawLine(23, 146, 33, 143, GC9A01A_YELLOW);
  tft.drawLine(24, 146, 34, 143, GC9A01A_YELLOW);

  tft.drawLine(23, 94, 33, 96, GC9A01A_YELLOW);
  tft.drawLine(24, 94, 34, 96, GC9A01A_YELLOW);

  tft.drawLine(49, 49, 56, 56, GC9A01A_YELLOW);
  tft.drawLine(50, 49, 57, 56, GC9A01A_YELLOW);

  tft.drawLine(94, 23, 96, 33, GC9A01A_YELLOW);
  tft.drawLine(95, 23, 97, 34, GC9A01A_YELLOW);

  tft.drawLine(145, 23, 143, 33, GC9A01A_YELLOW);
  tft.drawLine(146, 23, 144, 34, GC9A01A_YELLOW);

  tft.drawLine(190, 49, 183, 56, GC9A01A_YELLOW);
  tft.drawLine(191, 50, 184, 57, GC9A01A_YELLOW);

  tft.drawLine(206, 96, 216, 94, GC9A01A_YELLOW);
  tft.drawLine(206, 97, 216, 95, GC9A01A_YELLOW);


}

void loop() {


  currentMillis = millis();
  if (currentMillis - startMillis >= period) {
    readSensorData();

  display_meter(0);
  Text(0);

    startMillis = currentMillis;
  }
}








  float normaliseSensorData(int m) {

    return (m - 104) / 0.1638;
  }


  void readSensorData(void) {
    float absolutePressure = normaliseSensorData(analogRead(A7));

    boostPressure = (absolutePressure - 830) / 14.504 ;


    if (boostPressure > boostMax) boostMax = boostPressure;
    if (boostPressure < boostMin) boostMin = boostPressure;
  }