A nice portable ham project

GPS Baro Clock

/*
   UTC/Baro GPS Clock
    Final release V4
    Copyright Dec. 2023 - Adrian, YO3HJV
    https://yo3hjv.blogspot.com
    
      Required parts:
      -NodeMCU
      -uBlox Neo-6 GPS unit
      -BME280 I2C Baro-Temp module
      -1.28" SPI TFT ST7735
      -300 - 470KOhm resistor (something in this range). 
      The ratio of the voltage divider will be calculated and included in the code.
          
      !!!!!!!!!!!!!!!!!!!!!!!!-ATTENTION-!!!!!!!!!!!!!!!!!!!!!!
       All Vcc from GPS, TFT, BME goes to 3V pin on the NodeMCU
       DO NOT CONNECT TO THE BATTERY UNDER NO CIRCUMSTANCES !!!
      *********************************************************
          Connections, relative to NodeMCU pins numbering:
          TFT         NodeMCU pin#
          ________________________
          CS            D8
          D/C           D4
          DIN           D7
          CLK           D5
          RST           RST
          BL            3V
              
          GPS         NodeMCU pin#
          ________________________
          Tx            D2
          Rx            D6
          GND           GNC
          Vcc           3V          

          BME280    
          ________________________
          I2C SDA       D1
          I2C SCL       D3
          GND           GND 
          Vcc           3V          
      
*/

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
#include <ESP8266WiFi.h>
#include <maidenhead.h>
#include <Wire.h>             
#include <Adafruit_GFX.h>     
#include <Adafruit_ST7735.h>  
#include <Adafruit_BME280.h>  

// TFT
#define TFT_RST -1  
#define TFT_CS D8   
#define TFT_DC D4   

Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_RST);

// BME280 address: 0x76 or 0x77 (0x77 is library default address)
#define BME280_I2C_ADDRESS 0x76
Adafruit_BME280 bme; 

//GPS
TinyGPSPlus gps;                       
TinyGPSCustom pdop(gps, "GPGSA", 15);  
SoftwareSerial SerialGPS(D2, D0);

int NO_OF_SAT = 0;
float ACT_HDOP = 0;

float Latitude, Longitude;
int year, month, date, hour, minute, second;
double Altitude;

String DateString, TimeString, LatitudeString, LongitudeString, SatString, HdopString, MaidString, PresString, AltString;


//  COLORS

int BLACK = 0;
int WHITE = 65535;
int RED = 63488;
int ORANGE = 64096;
int YELLOW = 65504;  // OK
int GREEN = 2016;
int CYAN = 2047;     // 
int AQUA = 1279;
int BLUE =  31;
int MAGENTA = 63519;
int PINK = 63743;

// DEFINE SPECIFIC COLORS FOR TFT ELEMENTS
 int BackGroundColor = BLACK;
 int HLinesColor = MAGENTA;               
 int BoxColor = RED;                      
 int VLinesColor = WHITE;                
 int DotColor = WHITE;                    
 int FixedTextColor = WHITE; 
 int CoordColor = YELLOW; 
 int STextColor =  WHITE;
 int BTextColor = YELLOW;
 int QNHtextColor = RED;
 int DATEtextColor = YELLOW;
 int CelsiusColor = WHITE;  
 int DotGraphColor = WHITE;  
 int BoxFillColor = BLUE;          

unsigned long previous_BME_Millis = 0;
unsigned long current_BME_Millis = 0;
const long interval_TFTbme = 300;    // Pressure polling interval

unsigned long previous_BATT_Millis = 0;
unsigned long current_BATT_Millis = 0;
const long interval_BATT = 300;      // Battery voltage polling interval

// Barometer graphic area
const int graphWidth = 128;
const int graphHeight = 20;    
int xPos = 1;         
int yPos = 123;    

float pres = 0;
float temp = 0;

int i = 0;
int hdop = 9;

const float V_divider_ratio = 5.500;  // Replace with your value calculated from real values
                                     // then fine tune the value with DEBUG_BATT function
float Vbat = 0;
const int vReadings = 4;             // Number of readings to average voltage
float voltageReadings[vReadings] = {4}; 
int readIndex = 0;
int j = 0;

/*  Uncomment for specific debugging on Serial
    I strongly reccomend to use one at a time and not all of them    
*/
    //#define DEBUG 1                      // Uncomment to start serial scaffold debugging
    //#define DEBUG_GPS 1                  // GPS Library tools for debug
    //#define DEBUG_HDOP 1                       
    //#define DEBUG_TFT_BME 1              // Pressure and Temperature value
    //#define DEBUG_TFT_BAROGRAPH 1        // Pressure graphic math  
    //#define DEBUG_BATT 1                 // Battery readings
    //#define DEBUG_XPOS 1
 
unsigned long previous_BARO_Millis = 0;
unsigned long current_BARO_Millis = 0;
const long interval_BARO = 1500;        // msec - when the Pressure readings are made - time interval between readings
const int numPresReadings = 10;         // Number of readings to average    
float pressures[numPresReadings];
int currentReadingIndex = 0;
float sumPressures = 0;
int result = 10;
  
 
void setup() {
      Wire.begin(D1, D3);             
      Serial.begin(115200);
      SerialGPS.begin(9600);
  
      tft.initR(INITR_BLACKTAB);     
      tft.fillScreen(ST7735_BLACK);  
      TFT_static(); 
      
        bool status;
        status = bme.begin(0x76);
        if (!status) {
          Serial.println("BME280 Error! Check wiring first");
          while (1)
            ;
      }
}

void loop() {          
        TFT_Baro_Graph();    
        current_BATT_Millis = millis();        
        if (current_BATT_Millis - previous_BATT_Millis >= interval_BATT) {
                previous_BATT_Millis = current_BATT_Millis;
                TFT_batt();
                j=++j;                                                     
            }

        current_BME_Millis = millis();                
        if (current_BME_Millis - previous_BME_Millis >= interval_TFTbme) {
                previous_BME_Millis = current_BME_Millis;
                TFT_BME();
        }                          

         while (SerialGPS.available() > 0)
                      if (gps.encode(SerialGPS.read())) {
                        if (gps.location.isUpdated()) {
                          Latitude = gps.location.lat();
                          LatitudeString = String(Latitude, 6); 
                          Longitude = gps.location.lng();
                          LongitudeString = String(Longitude, 6); 
                        TFT_LatLon();
                        TFT_Maidenhead();        
                        }

                        if (gps.date.isUpdated()) {
                          DateString = "";
                          date = gps.date.day();
                          month = gps.date.month();
                          year = gps.date.year();

                          if (date < 10)
                            DateString = '0';
                            DateString += String(date);
                            DateString += "/";

                          if (month < 10)
                            DateString += '0';
                            DateString += String(month);
                            DateString += "/";

                          if (year < 10)
                            DateString += '0';
                            DateString += String(year);
                              
                        TFT_Date();                       
                                
                        }

                        if (gps.time.isUpdated()) {
                          TimeString = "";
                          hour = gps.time.hour();  //adjust UTC by adding "+3"
                          minute = gps.time.minute();
                          second = gps.time.second();

                          if (hour < 10)
                            TimeString = '0';
                          TimeString += String(hour);
                          TimeString += ":";

                          if (minute < 10)
                            TimeString += '0';
                          TimeString += String(minute);
                          TimeString += ":";

                          if (second < 10)
                            TimeString += '0';
                          TimeString += String(second);
                        TFT_Time();
                        }

                        if (gps.altitude.isUpdated() || gps.satellites.isUpdated() || gps.hdop.isUpdated()) {
                          TFT_MetaGPS(); 
                            #ifdef DEBUG
                            Serial.print("Altitude set: ");
                            Serial.println(gps.altitude.meters());
                            #endif
                        }
                      }
                          
                          #ifdef DEBUG_GPS
                              Serial.print("Chars Processed= ");
                              Serial.println(gps.charsProcessed());
                              Serial.print("Sentences that passed checksum= ");
                              Serial.println(gps.passedChecksum());
                              Serial.print("Sentences that failed checksum= ");
                              Serial.println(gps.failedChecksum());
                              Serial.print("Soft Serial device overflowed? ");
                              Serial.println(SerialGPS.overflow() ? "YES!" : "No");
                              Serial.print("Sentences with Fix: ");
                              Serial.println(gps.sentencesWithFix() );                            
                              Serial.println();
                              Serial.print(F("ALTITUDE   Fix Age= "));
                              Serial.print(gps.altitude.age());
                              Serial.print(F("ms Raw= "));
                              Serial.print(gps.altitude.value());
                              Serial.println(F(" Meters="));
                          #endif                       
}

void TFT_MetaGPS() {  
                NO_OF_SAT = gps.satellites.value();
                SatString = "";
                SatString = String(NO_OF_SAT);
                ACT_HDOP = gps.hdop.hdop();                     
                hdop = map(ACT_HDOP, 1, 100, 0, 9);

                    #ifdef DEBUG_HDOP
                    Serial.println();
                          Serial.print("Sat: ");
                          Serial.println(SatString);

                          Serial.print("HDOP: ");
                          Serial.println(hdop);
                          
                    #endif
              
                      // Sat#
                      tft.setTextColor(STextColor, ST7735_BLACK);
                      tft.setTextSize(1);
                      tft.setCursor(112, 10);
                      tft.setTextWrap(false);
                      tft.print(SatString);

                      // HDOP
                      tft.setTextColor(STextColor);
                      tft.setTextSize(1);
                      tft.setCursor(6, 151);
                      tft.setTextWrap(false);
                      tft.print(hdop);

                      // GPS a.s.l.
                      tft.setTextColor(BTextColor);
                      tft.setTextSize(2);
                      tft.setCursor(42, 71);
                      tft.setTextWrap(false);

              if(gps.altitude.isValid()) {       
                      tft.print(Altitude); 
              }        
              else
                      tft.print(" -");       
}

void TFT_Maidenhead() {  
          char* locator6 = get_mh(Latitude, Longitude, 6);  
          MaidString = String(locator6);
              tft.setTextColor(BTextColor);
              tft.setTextSize(2);
              tft.setCursor(42, 48);
              tft.setTextWrap(false);
              tft.print(MaidString);
                    #ifdef DEBUG
                    Serial.print("Loc QTH 6 char locator is ");
                    Serial.println(MaidString);  
                    #endif
}

void TFT_Time(){
      tft.setTextColor(BTextColor ,ST7735_BLACK);
      tft.setTextSize(2);
      tft.setCursor(32, 25);
      tft.setTextWrap(false);
      tft.print(TimeString);            
                    #ifdef DEBUG
                    Serial.print("Time: ");
                    Serial.println(TimeString);  
                    #endif                       
}

void TFT_Date(){     
      tft.setTextColor(DATEtextColor ,ST7735_BLACK);
      tft.setTextSize(1);
      tft.setCursor(67, 95);
      tft.setTextWrap(false);
      tft.print(DateString);
                    #ifdef DEBUG
                    Serial.print("Date: ");
                    Serial.println(DateString); 
                    #endif
}

void TFT_LatLon() {
      tft.setTextColor(CoordColor ,ST7735_BLACK);
      tft.setTextSize(1);
      tft.setCursor(27, 0);
      tft.setTextWrap(false);
      tft.print(LatitudeString);

      tft.setTextColor(CoordColor ,ST7735_BLACK);
      tft.setTextSize(1);
      tft.setCursor(27, 10);
      tft.setTextWrap(false);
      tft.print(LongitudeString);

            #ifdef DEBUG
            Serial.print("Lat: ");
            Serial.println(LatitudeString);  // 
            Serial.print("Lon: ");
            Serial.println(LongitudeString);  // 
            #endif
}

void TFT_BME() {  // Just show Pres and Temp on TFT
          temp = bme.readTemperature(); 
          pres = bme.readPressure();     
          
              tft.setTextColor(STextColor, BackGroundColor);
              tft.setTextSize(1);
              tft.setCursor(73, 151);
              tft.setTextWrap(false);
          if (temp < 0)      
              tft.printf("-%02u", (int)abs(temp));
          else
              tft.printf(" %02u", (int)temp);
                   
              tft.setTextColor(STextColor, BackGroundColor);
              tft.setTextSize(1);
              tft.setCursor(29, 151);
              tft.setTextWrap(false);
          if (pres < 1000) {
              tft.printf("%3u.%01u", (int)(pres / 100), (int)((uint32_t)pres % 100) / 10);
          } else {
              tft.printf("%4u.%01u", (int)(pres / 100), (int)((uint32_t)pres % 100) / 10);
          }
 
                  #ifdef DEBUG_TFT_BME
                    Serial.println("TFT_BME()");
                    Serial.print("Pressure: ")
                    Serial.println(pres);
                    Serial.print("Temperature: ")
                    Serial.println(temp);
                    Serial.println();
                  #endif      
}

void TFT_Baro_Graph () {
              unsigned long current_BARO_Millis = millis();
              if (current_BARO_Millis - previous_BARO_Millis >= interval_BARO) {
                previous_BARO_Millis = current_BARO_Millis;
                float pres = bme.readPressure();
                pressures[currentReadingIndex] = pres;
                sumPressures += pres;
                currentReadingIndex = (currentReadingIndex + 1) % numPresReadings;                
                if (currentReadingIndex == 0) {
                  float averagePressure = sumPressures / numPresReadings;               
                      #ifdef DEBUG_TFT_BAROGRAPH
                            Serial.println();
                            Serial.print("Average Pressure: ");
                            Serial.println(averagePressure, 2 );
                          #endif            
                                            
                                  // Convert averagePressure to a string
                  char buffer[15];  // Adjust the buffer size based on the expected length
                  snprintf(buffer, sizeof(buffer), "%.2f", averagePressure);
                  
                            #ifdef DEBUG_TFT_BAROGRAPH
                            Serial.print("String buffer:");
                            Serial.println(buffer);
                            #endif
                // Extract the 5th and 6th digits from the right, counting from the decimal point
                  int length = strlen(buffer);
                  int fifthDigit = (length >= 5) ? (buffer[length - 5] - '0') : 0;
                  int sixthDigit = (length >= 6) ? (buffer[length - 6] - '0') : 0;


                          #ifdef DEBUG_TFT_BAROGRAPH
                                Serial.print("Fifth Digit: ");
                                Serial.println(fifthDigit);
                                Serial.print("Sixth Digit: ");
                                Serial.println(sixthDigit);
                          #endif

                                // Combine the second and third digits into a single value
                                int extractedValue = sixthDigit * 10 + fifthDigit;

                          #ifdef DEBUG_TFT_BAROGRAPH
                                Serial.print("Extracted Value: ");
                                Serial.println(extractedValue);
                          #endif              
                  drawPixel();                
                  currentReadingIndex = 0;
                  sumPressures = 0;
    }
  }
   
}

void drawPixel(){
                  xPos += 1; 
                  if(xPos >126){
                          tft.fillRect(0, 114, 128, 20, BoxFillColor);
                          tft.drawRect(0, 114, 128, 20, BoxColor);
                          xPos = 1;                    
                            }        
                  yPos = map (result, 0, 19, 132, 115);      
                  tft.drawPixel(xPos, yPos, DotGraphColor);
                      #ifdef DEBUG_XPOS
                      Serial.print("xPos= ");
                      Serial.println(xPos);
                      #endif   
}

void TFT_batt() {
                      int adc = analogRead(A0);
                          #ifdef DEBUG_BATT
                          Serial.print("analogRead: ");
                          Serial.println(adc);
                          #endif  
                      float referenceVoltage = 1.0;                               // ADC reference voltage ESP8266
                      float voltage = adc * (referenceVoltage / 1023.0) * V_divider_ratio;  // 5.500 is ADC resistive voltage divider ratio
                      voltageReadings[readIndex] = voltage;
                      readIndex = (readIndex + 1) % vReadings;
                      float sumVoltages = 0;
                      for (int j = 0; j < vReadings; ++j) {
                        sumVoltages += voltageReadings[i];                                               
                                #ifdef DEBUG_BATT
                                Serial.print("j= ");
                                Serial.println(j);
                                #endif
                      }
                      float averageVoltage = sumVoltages / vReadings;
                              tft.setTextColor(STextColor, BackGroundColor);
                              tft.setTextSize(1);
                              tft.setCursor(97, 151);
                              tft.setTextWrap(false);
                              tft.printf(" %0.1f", averageVoltage);
                      #ifdef DEBUG_BATT
                      Serial.print("Average Voltage: ");
                      Serial.println(averageVoltage);
                      #endif                  
}

void TFT_static() {  
  tft.drawLine(0, 20, 127, 20, HLinesColor);       // Orizontala de sub Lat/Lon - prima de sus
  tft.drawLine(0, 43, 127, 43, HLinesColor);       // Orizontala de sub UTC - a doua de sus
  tft.drawLine(0, 66, 127, 66, HLinesColor);       // Orizontala de sub QTH Locator - a treia de sus
  tft.drawLine(0, 137, 127, 137, HLinesColor);     // Orizontala de sub GPSasl - a patra de sus
  tft.drawLine(0, 89, 127, 89, HLinesColor);       // Orizontala de sub graficul QNH - ultima de jos, sub Box
  
  tft.drawRect(0, 114, 128, 20, BoxColor);         // Box pentru grafic QNH
  tft.fillRect(0, 114, 128, 20, BoxFillColor);
    tft.drawPixel(0, 112, DotColor);               // Box ticks
    tft.drawPixel(7, 112, DotColor);
    tft.drawPixel(15, 112, DotColor);
    tft.drawPixel(23, 112, DotColor);
    tft.drawPixel(31, 112, DotColor);
    tft.drawPixel(39, 112, DotColor);
    tft.drawPixel(47, 112, DotColor);
    tft.drawPixel(55, 112, DotColor);
    tft.drawPixel(63, 112, DotColor);
    tft.drawPixel(71, 112, DotColor);
    tft.drawPixel(79, 112, DotColor);
    tft.drawPixel(87, 112, DotColor);
    tft.drawPixel(95, 112, DotColor);
    tft.drawPixel(103, 112, DotColor);
    tft.drawPixel(111, 112, DotColor);
    tft.drawPixel(119, 112, DotColor);
    tft.drawPixel(127, 112, DotColor);
 
  tft.drawLine(97, 1, 97, 16, VLinesColor);        // vertical Up Right Sat number                            
  tft.drawLine(21, 140, 21, 158, VLinesColor);     // First vertical down left
  tft.drawLine(69, 140, 69, 158, VLinesColor);     // Second
  tft.drawLine(96, 140, 96, 158, VLinesColor);     // Third

  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(1, 0);
  tft.setTextWrap(false);
  tft.print("Lat:");
  
  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(1, 10);
  tft.setTextWrap(false);
  tft.print("Lon:");

  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(106, 0);
  tft.setTextWrap(false);
  tft.print("SAT:");

  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(1, 29);
  tft.setTextWrap(false);
  tft.print("UTC:");
  
  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(1, 50);
  tft.setTextWrap(false);
  tft.print("Loc:");

  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(1, 74);
  tft.setTextWrap(false);
  tft.print("G.asl:");  
  
  tft.setTextColor(BTextColor, BackGroundColor);     
  tft.setTextSize(2);
  tft.setCursor(108, 71);
  tft.setTextWrap(false);
  tft.print("m");

    tft.setTextColor(QNHtextColor, BackGroundColor);   
    tft.setTextSize(1);
    tft.setCursor(1, 95);
    tft.setTextWrap(false);
    tft.print("QNH survey:");
  
  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(2, 140);
  tft.setTextWrap(false);
  tft.print("DOP");
  
  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(26, 140);
  tft.setTextWrap(false);
  tft.print("QNH hPa");

  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(73, 140);
  tft.setTextWrap(false);
  tft.print("T");

  tft.drawCircle(85, 142, 2, FixedTextColor);
  tft.setTextColor(FixedTextColor);
  tft.setTextSize(1);
  tft.setCursor(89, 140);
  tft.setTextWrap(false);
  tft.print("C");
  
  tft.setTextColor(FixedTextColor, BackGroundColor);
  tft.setTextSize(1);
  tft.setCursor(102, 140);
  tft.setTextWrap(false);
  tft.print("Batt");
  
  tft.setTextColor(STextColor, BackGroundColor);  
  tft.setTextSize(1);
  tft.setCursor(121, 151);
  tft.setTextWrap(false);
  tft.print("V");
}