ESP8266 DHT22 RGB Matrix P4 Weather Station Clock Web Server

Weather Station Clock Scrolling Message Matrix P4 Web Server ESP8266

Arduino tutorial: 
RGB Matrix p4 64*32 
DHT11 
ESP8266

 This project with esp32 

ESP32 P4 32x64 RGB Led Matrix SD Card DHT11 RTC DS1307

ESP32 DHT11 RTC DS1307 SD Card P4 RGB Led Matrix

Schema

ARDUINO 1.8.9
Weather Station Clock Scrolling Message Matrix P4 Web Server ESP8266

Library

DHT Sensor Library:
https://github.com/adafruit/DHT-sensor-library
esp8266 library (nodemcu) found at
https://github.com/esp8266/Arduino
RGB matrix Panel Library:
https://github.com/2dom/PxMatrix
Adafruit_GFX Library:
https://github.com/adafruit/Adafruit-GFX-Library
package_esp8266com_index.json:
http://arduino.esp8266.com/stable/package_esp8266com_index.json

Code

// REQUIRES the following Arduino libraries:
// - DHT Sensor Library: https://github.com/adafruit/DHT-sensor-library
// - RGB matrix Panel Library: https://github.com/2dom/PxMatrix
// - Adafruit_GFX Library: https://github.com/adafruit/Adafruit-GFX-Library
// - esp8266 library (nodemcu) found at https://github.com/esp8266/Arduino
// - package_esp8266com_index.json found at http://arduino.esp8266.com/stable/package_esp8266com_index.json
// Find All "Great Projects" Videos : https://www.youtube.com/channel/UCCC8DuqicBtP3A_aC53HYDQ/videos


#include "DHT.h"
#define DHTPIN 0 
#define DHTTYPE DHT22   // DHT 22
DHT dht(DHTPIN, DHTTYPE);
#include <ESP8266WiFi.h>
#include <time.h>
#include <Adafruit_GFX.h>
#include <FreeMonoBold12pt7b.h>
#include <kongtext4pt7b.h>
#include <PxMatrix.h>
#include <Ticker.h>
Ticker display_ticker;
#define P_LAT 16
#define P_A 5
#define P_B 4
#define P_C 15
#define P_D 12
#define P_OE 2
// Pins for LED MATRIX
#define matrix_width 64
#define matrix_height 32
int timezone = 0;
int dst = 0;
  float Humi;
  float Temp;
 static uint32_t lastTime = 0; // millis() memory
static bool flasher = false;  // seconds passing flasher
uint8_t frameDelay = 10;  // default frame delay value

int h,m,s,d;
uint8_t dow;
int  day;
uint8_t month;
String  year;
String date;
String WeatherT;
String WeatherH;
String  text;
#define MAX_MESG  9
#define MAX_MES  20
#define MAX_ME  50
#define BUF_SIZE  612
char curMessage[BUF_SIZE] = { "Hello! Enter new message?" };
char newMessage[BUF_SIZE];
bool newMessageAvailable = false;
static bool Mode = true; 
uint8_t r=0, g=0, b=0;
unsigned int NewRTCh = 24;
unsigned int NewRTCm = 60;
unsigned int NewRTCs = 10;
char szTime[4];    // 00
char szMesg[10] = "";
  char  szBuf[10];
  
const char* ssid     = "**********";     // SSID of local network
const char* password = "**********";   // Password on network
WiFiServer server(80);

// This defines the 'on' time of the display is us. The larger this number,
// the brighter the display. If too large the ESP will crash
uint8_t display_draw_time=10; //10-50 is usually fine

//PxMATRIX display(matrix_width,matrix_height,P_LAT, P_OE,P_A,P_B,P_C);
PxMATRIX display(64,32,P_LAT, P_OE,P_A,P_B,P_C,P_D);
//PxMATRIX display(64,64,P_LAT, P_OE,P_A,P_B,P_C,P_D,P_E);

// Some standard colors
uint16_t myRED = display.color565(255, 0, 0);
uint16_t myGREEN = display.color565(0, 255, 0);
uint16_t myBLUE = display.color565(0, 0, 255);
uint16_t myWHITE = display.color565(255, 255, 255);
uint16_t myYELLOW = display.color565(255, 255, 0);
uint16_t myCYAN = display.color565(0, 255, 255);
uint16_t myMAGENTA = display.color565(255, 0, 255);
uint16_t myBLACK = display.color565(255, 255, 255);

uint16_t myCOLORS[8]={myRED,myGREEN,myBLUE,myWHITE,myYELLOW,myCYAN,myMAGENTA,myBLACK};


#ifdef ESP8266
// ISR for display refresh
void display_updater()
{
  display.display(display_draw_time);
}
#endif



void display_update_enable(bool is_enable)
{

#ifdef ESP8266
  if (is_enable)
    display_ticker.attach(0.002, display_updater);
  else
    display_ticker.detach();
#endif

}

void(* resetFunc) (void) = 0;//declare reset function at address 0
char *mon2str(uint8_t mon, char *psz, uint8_t len)
{
  static const char str[][4] PROGMEM =
  {
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  };

  *psz = '\0';
  mon--;
  if (mon < 12)
  {
    strncpy_P(psz, str[mon], len);
    psz[len] = '\0';
  }

  return(psz);
}
char *dow2str(uint8_t code, char *psz, uint8_t len)
{
  static const char str[][10] PROGMEM =
  {
    "Sunday", "Monday", "Tuesday", "Wednesday",
    "Thursday", "Friday", "Saturday"
  };

  *psz = '\0';
  code--;
  if (code < 7)
  {
    strncpy_P(psz, str[code], len);
    psz[len] = '\0';
  }

  return(psz);
}
void getDateWeb()
{
  date = dow2str(dow, szBuf, sizeof(szBuf)-1);
  date += " ";
  if (day < 10) { date += "0";  }
  date += day;
  date += mon2str(month, szBuf, sizeof(szBuf)-1);
  date += year;
  date += "   ";
  if (h < 10) { date += "0";  }
  date += h;
  date += ":";
  if (m < 10) { date += "0";  }
  date += m;
  date += ":";
  if (s < 10) { date += "0";  }
  date += s;
}
void getWeather()
{
  dht.begin();
  Temp = dht.readTemperature();
  Humi = dht.readHumidity();
  if (isnan(Humi) || isnan(Temp)) {
      delay(100);
    return;
  }
  WeatherT = "Temperature : ";
  WeatherT += Temp;
  WeatherT += " $";
  WeatherH = "Humidity : ";
  WeatherH += Humi;
  WeatherH += " %";
}
void getDate()
// Code for reading date
{      
  text = mon2str(month, szBuf, sizeof(szBuf)-1);
        display.setCursor(0,0);
  display.fillRect(0, 0, 64, 8, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
  display.setTextColor(myRED);
  if (day < 10) { display.print("0");  }
  display.print(day);
  display.setTextColor(myGREEN);
  display.print(text);
  display.setTextColor(myRED);
  display.print(year);
  display.setFont();
}
void getDowe()
// Code for reading date
{
  text = dow2str(dow, szBuf, sizeof(szBuf)-1);
  uint16_t text_length = text.length();
  int xpos = (matrix_width - text_length*7)/2;
  display.setCursor(xpos,0);
  display.fillRect(0, 0, 64, 8, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
  uint8_t y = 0;
  for (y=0; y<10; y++) {
    display.setTextColor(Whel(y));
    display.print(text[y]);
    }
  display.setFont();
}  
void getRTCh(char *psz)
// Code for reading clock time
{
  sprintf(psz, "%02d", h);
  display.setCursor(0, 16); 
  display.setFont(&FreeMonoBold12pt7b);
  display.setTextColor(myMAGENTA);
  display.fillRect(0, 8, 24, 15, display.color565(0, 0, 0));
  display.print(szTime);
  display.setFont();
  NewRTCh=h;
}

void getRTCm(char *psz)
// Code for reading clock time
{
  sprintf(psz, "%02d", m);
  display.setCursor(26, 16); 
  display.setFont(&FreeMonoBold12pt7b);
  display.setTextColor(myMAGENTA);
  display.fillRect(26, 8, 25, 15, display.color565(0, 0, 0));
  display.print(szTime);
  display.setFont();
  NewRTCm=m;
}
void getTim(char *psz, bool f = true)
// Code for reading clock time
{
  if (NewRTCs != s/10) 
  {
  display.setCursor(20, 8); 
  display.setTextSize(2);
  display.setTextColor(myCOLORS[g]);
  display.fillRect(24, 12, 2, 6, display.color565(0, 0, 0));
    display.print(f ? ':' : ' ');
  display.setCursor(54, 10); 
  display.setTextSize(1);
  display.fillRect(54, 10, 10, 6, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
  display.setTextColor(myCOLORS[b]);
    display.print(f ? ' ' : '*');
  display.setFont();
  display.setCursor(51, 16); 
  display.setTextSize(1);
  display.setTextColor(myCOLORS[r]);
  sprintf(psz, "%02d", s);
  display.fillRect(51, 17, 13, 6, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
    display.print(szTime);
  display.setFont();
      NewRTCs=s/10;
    }
    else
  {
  display.setCursor(20, 8); 
  display.setTextSize(2);
  display.setTextColor(myCOLORS[g]);
  display.fillRect(24, 12, 2, 6, display.color565(0, 0, 0));
    display.print(f ? ':' : ' ');
  display.setCursor(54, 10); 
  display.setTextSize(1);
  display.fillRect(54, 10, 10, 6, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
  display.setTextColor(myCOLORS[b]);
    display.print(f ? ' ' : '*');
  display.setFont();
  display.setCursor(51, 16); 
  display.setTextColor(myCOLORS[r]);
  sprintf(psz, "%02d", s);
  display.fillRect(58, 17, 6, 6, display.color565(0, 0, 0));
  display.setFont(&kongtext4pt7b);
    display.print(szTime);
  display.setFont();
    }
}
void scroll_text(uint8_t ypos, unsigned long scroll_delay, String text)
  {  
    uint16_t text_length = text.length();
    // Asuming 5 pixel average character width
    for (int xpos=matrix_width; xpos>-(matrix_width+text_length*5); xpos--)
    {
  handleWiFi();
      display.setCursor(xpos,ypos);
      display.fillRect(0, 23, 64, 8, display.color565(0, 0, 0));
      display.setFont(&kongtext4pt7b);
      display.print(text);
      display.setFont();
      delay(scroll_delay);
      yield();
  if (millis() - lastTime >= 1000)
  {
    lastTime = millis();
    updateTime();
    getTim(szTime, flasher);
    flasher = !flasher;
    if (NewRTCh != h) 
   {
        getTime();
        getRTCh(szTime);
   }
    if (NewRTCm != m) 
   {
      getRTCm(szTime);
      getWeather();
      Mode = true;
   }
    }
}
      r++;
      if(r == 8) {
        r = 0;
        g++;
        if(g == 8) {
          g = 0;
          b++;
        if(b == 8) {
          b = 0;
        }
        }
      }
}

const char WebResponse[] = "HTTP/1.1 200 OK\nContent-Type: text/html\n\n";

char WebPage[] =
"<!DOCTYPE html>" \
"<html>" \
"<head>" \
"<meta http-equiv=\"refresh\" content=\"60\"; url=\"http://192.168.1.24\" />" \
"<title>ESP8266 Weather Station</title>" \
"<script>" \
"strLine = \"\";" \
"function DisplayCurrentTime()" \
"{" \
"  var dt = new Date();" \
"  var weekday = new Array(7);" \
"  weekday[0] = \"Sunday\";" \
"  weekday[1] = \"Monday\";" \
"  weekday[2] = \"Tuesday\";" \
"  weekday[3] = \"Wednesday\";" \
"  weekday[4] = \"Thursday\";" \
"  weekday[5] = \"Friday\";" \
"  weekday[6] = \"Saturday\";" \
"  var dow = weekday[dt.getDay()];" \
"  document.getElementById(\"datetime\").innerHTML = (dow) +\" \"+ (dt.toLocaleString());" \
"  setTimeout('DisplayCurrentTime()', 1000);" \
"}" \
"function SendData()" \
"{" \
"  nocache = \"/&nocache=\" + Math.random() * 1000000;" \
"  var request = new XMLHttpRequest();" \
"  strLine = \"&MSG=\" + document.getElementById(\"data_form\").Message.value;" \
"  strLine = strLine + \"/&SP=\" + document.getElementById(\"data_form\").Speed.value;" \
"  request.open(\"GET\", strLine + nocache, false);" \
"  request.send(null);" \
"}" \
"function restart()" \
"{" \
"  nocache = \"/&nocache=\" + Math.random() * 1000000;" \
"  var request = new XMLHttpRequest();" \
"  strLine = \"/&Rst=\" + document.getElementById(\"date_form\").rerset.value;" \
"  request.open(\"GET\", strLine + nocache, false);" \
"  request.send(null);" \
"}" \
"function resttime()" \
"{" \
"  nocache = \"/&nocache=\";" \
"  var request = new XMLHttpRequest();" \
"  strLine = \"/&RT=\" + document.getElementById(\"date_form\").restmie.value;" \
"  request.open(\"GET\", strLine + nocache, false);" \
"  request.send(null);" \
"}" \
      "document.addEventListener('DOMContentLoaded', function() {" \
        "DisplayCurrentTime();" \
      "}, false);" \
"</script>" \
      "<style>" \
         "body {" \
        "text-align: center;" \
             "margin: 5;" \
             "padding: 5;" \
             "background-color: rgba(72,72,72,0.4);" \
         "}" \
         "#wrapper { " \
     "margin: 0 auto;" \ 
     "width: 100%;" \
     "}" \
         "#form-div {" \
         "background-color: rgba(72,72,72,0.4);" \
         "padding-left: 10px;" \
         "padding-right: 10px;" \
         "padding-bottom: 80px;" \
         "padding-top: 5px;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
         "}" \
         ".data-input {" \
         "padding: 10px 5px 5px 5px;" \
         "background-color: #bbbbff;" \
         "font-size:26px;" \
         "color:red;" \
         "padding-bottom:46px;" \
         "border: 5px solid #444444;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
         "}" \
         ".button-blue {" \
         "padding: 5px 5px 5px 5px;" \
         "float:left;" \
         "width: 100%;" \
         "border: #fbfb00 solid 3px;" \
         "cursor:pointer;" \
         "background-color: #4444ff;" \
         "color:white;" \
         "font-size:20px;" \
         "padding-bottom:5px;" \
         "font-weight:700;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
         "}" \
         ".button-blue:hover {" \
         "background-color: #2222aa;" \
         "color: #ff93bd;" \
         "}" \
         ".text {" \
         "background-color: #ff0000;" \
         "font-size:76px;" \
         "color: #ffff99;" \
         "}" \
      "table {" \
        "border: 2px solid #ff00ff;" \
        "background-color: #ffffff;" \
        "width:100%;" \
         "color: #0000ff;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
      "}" \
      "h1 {" \
        "color: #ff0000;" \
         "background-color: #ffff00;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
      "}" \
      "tr {" \
        "border: 2px solid #ff0000;" \
         "background-color: #ffff00;" \
         "color: #ff0000;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
      "}" \
      "td {" \
        "border: 2px solid #ff0000;" \
        "padding: 16px;" \
         "-moz-border-radius: 7px;" \
         "-webkit-border-radius: 7px;" \
      "}" \
   "</style>" \
   "</head>" \
   "<body>" \
   "<div id=\"wrapper\">" \
   "<div id=\"form-div\">" \
   "<div class=\"submit\">" \
   "<h1>ESP8266 Weather Station</h1>" \
   "<h1>Local Date-Time: <span id=\"datetime\"></span></h1>" \
   "</div>" \
  "<form id=\"data_form\" name=\"frmText\">" \
  "<div class=\"data-input\">" \
   "Message <input type=\"text\" name=\"Message\" maxlength=\"655\" class=\"button-white\" style=\"width:90%;height:35px;font-size:30px\">" \
   "<input type=\"range\" name=\"Speed\"min=\"0\" max=\"50\" class=\"button-blue\" style=\"width:76%\">" \
   "<input type=\"submit\" value=\"Send\" style=\"width:20%;float:right\" onclick=\"SendData()\" class=\"button-blue\">" \
   "</div></form></br></br>" \
  "<form id=\"date_form\" name=\"frmText\">" \
   "<div class=\"data-input\">" \
   "<b class=\"button-blue\" style=\"width:8%\">GMT+</b>" \
   "<input type=\"number\" value=\"0\" name=\"restmie\" min=\"-12\" max=\"+12\" class=\"button-blue\" style=\"width:6%\">" \
   "<input type=\"submit\" value=\"Update Time\" onClick=\"resttime()\" class=\"button-blue\" style=\"width:80%\">" \
   "</div><div class=\"data-input\">" \
   "<input type=\"submit\" name = \"rerset\" value=\"Restart ESP8266\" onClick=\"restart()\" class=\"button-blue\">" \
   "</div></form>" \
   "<div class=\"data-input\">" \
    "<table>" \
   "<tr>" \
        "<td style=\"width:48%\"><b>Temp. Celsius</b></td>" \
        "<td style=\"width:48%\"><b>Humidity</b></td>" \
  "</tr>" \
  "<tr class=\"text\">";

uint8_t htoi(char c)
{
  c = toupper(c);
  if ((c >= '0') && (c <= '9')) return(c - '0');
  if ((c >= 'A') && (c <= 'F')) return(c - 'A' + 0xa);
  return(0);
}

void getData(char *szMesg, uint8_t len)
// Message may contain data for:
// New text (/&MSG=)
// Invert (/&I=)
// Speed (/&SP=)
{
  char *pStart, *pEnd;      // pointer to start and end of text

  // check text message
  pStart = strstr(szMesg, "/&MSG=");
  if (pStart != NULL)
  {
    char *psz = newMessage;

    pStart += 6;  // skip to start of data
    pEnd = strstr(pStart, "/&");

    if (pEnd != NULL)
    {
      while (pStart != pEnd)
      {
        if ((*pStart == '%') && isdigit(*(pStart + 1)))
        {
          // replace %xx hex code with the ASCII character
          char c = 0;
          pStart++;
          c += (htoi(*pStart++) << 4);
          c += htoi(*pStart++);
          *psz++ = c;
        }
        else
          *psz++ = *pStart++;
      }

      *psz = '\0'; // terminate the string
      newMessageAvailable = (strlen(newMessage) != 0);
    }
  }
  // check speed
  pStart = strstr(szMesg, "/&SP=");
  if (pStart != NULL)
  {
    pStart += 5;  // skip to start of data

    int16_t speed = atoi(pStart);
    frameDelay = speed;
  }
  // check reset time
  pStart = strstr(szMesg, "/&RT=");
  if (pStart != NULL)
  {
    pStart += 5;  // skip to start of data

    timezone = atoi(pStart);
    getTime();
    updateTime();
  }
  // check reset
  pStart = strstr(szMesg, "/&Rst=");
  if (pStart != NULL)
  {
    pStart += 6;  // skip to start of data
    if(*pStart != NULL)
  {
      resetFunc();
  }
  }
}

void handleWiFi(void)
{
  static enum { S_IDLE, S_WAIT_CONN, S_READ, S_EXTRACT, S_RESPONSE, S_DISCONN } state = S_IDLE;
  static char szBuf[1024];
  static uint16_t idxBuf = 0;
  static WiFiClient client;
  static uint32_t timeStart;

  switch (state)
  {
  case S_IDLE:   // initialise
    idxBuf = 0;
    state = S_WAIT_CONN;
    break;

  case S_WAIT_CONN:   // waiting for connection
  {
    client = server.available();
    if (!client) break;
    if (!client.connected()) break;
    timeStart = millis();
    state = S_READ;
  }
  break;

  case S_READ: // get the first line of data

    while (client.available())
    {
      char c = client.read();

      if ((c == '\r') || (c == '\n'))
      {
        szBuf[idxBuf] = '\0';
        client.flush();
        state = S_EXTRACT;
      }
      else
        szBuf[idxBuf++] = (char)c;
    }
    if (millis() - timeStart > 1000)
    {
      state = S_DISCONN;
    }
    break;

  case S_EXTRACT: // extract data
    // Extract the string from the message if there is one
    getData(szBuf, BUF_SIZE);
    state = S_RESPONSE;
    break;

  case S_RESPONSE: // send the response to the client
    // Return the response to the client (web page)
    getDateWeb();
    client.print(WebResponse);
    client.print(WebPage);
    sendXMLFile(client);
    state = S_DISCONN;
    break;

  case S_DISCONN: // disconnect client
    client.flush();
    client.stop();
    state = S_IDLE;
    break;

  default:  state = S_IDLE;
  }
}
void setup() {
  // Define your display layout here, e.g. 1/8 step
  display.begin(16);

  // Define your scan pattern here {LINE, ZIGZAG, ZAGGIZ, WZAGZIG, VZAG} (default is LINE)
  //display.setScanPattern(LINE);

  // Define multiplex implemention here {BINARY, STRAIGHT} (default is BINARY)
  //display.setMuxPattern(BINARY);

  display.setFastUpdate(true);
    display.setRotation(0); // we don't wrap text so it scrolls nicely
  display.clearDisplay();
  display.setTextColor(myCYAN);
  display.setCursor(2,0);
  display.println("Connecting");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    display.print(".");
  }
  display.setTextWrap(false); 
  display.clearDisplay();
  display.println(""); 
  display.print("WiFi OK"); 
  display_update_enable(true);
  delay(3000);
  getDate();
  getWeather();
  // Start the server
  server.begin();
  newMessage[0] = '\0';
}

void loop() {
    if (newMessageAvailable)
    {
      strcpy(curMessage, newMessage);
      newMessageAvailable = false;
    }
    if (Mode)
    {
        getDowe();
  scroll_text(23,12,WeatherT);
  scroll_text(23,12,WeatherH);
        getDate();
      Mode = false;
    }
scroll_text(23,frameDelay,curMessage);
  }
void getTime()
{

  configTime(timezone * 3600, dst, "pool.ntp.org","time.nist.gov");

  while(!time(nullptr)){
     display.print(".");
  }
}

void updateTime()
{
  time_t now = time(nullptr);
  struct tm* p_tm = localtime(&now);
      dow = p_tm->tm_wday+1;
      day = p_tm->tm_mday;
      month = p_tm->tm_mon + 1;
      year = p_tm->tm_year + 1900;
      h = p_tm->tm_hour;
      m = p_tm->tm_min;
      s = p_tm->tm_sec;
}
void sendXMLFile(WiFiClient cl){
  dht.begin();
  Temp = dht.readTemperature();
  Humi = dht.readHumidity();
  if (isnan(Humi) || isnan(Temp)) {
      delay(100);
    return;
  }
  // send rest of HTTP header
     cl.print("<td style=\"width:48%\">");
     cl.print(Temp);
     cl.print(" *C</td><td style=\"width:48%\">");
     cl.print(Humi);
     cl.print(" %</td></tr></table></div><br>");
     cl.print("<div class=\"submit\">");
     cl.print("<input type=\"button\" value=\"Actualiser\"");
     cl.print(" onClick=\"javascript:window.location.reload()\" class=\"button-blue\">");
     cl.print("</div><div class=\"submit\">");
     cl.print("<input type=\"button\" value=\"More Progets\" onClick=\"Javascript:window.open('https://www.youtube.com/channel/UCCC8DuqicBtP3A_aC53HYDQ/videos');\"");
     cl.print(" class=\"button-blue\"></div>");
     cl.print("<div class=\"submit\" style=\"width:100%\"><h1>ESP8266 Date-Time: ");
     cl.print(date);
     cl.print("</h1></div>");
     cl.print("</div></div></body></html>");
}
// Input a value 0 to 24 to get a color value.
// The colours are a transition r - g - b - back to r.
uint16_t Wheel(byte WheelPos) {
  if(WheelPos < 2) {
   return display.color565(255, 0, 0);
  } else if(WheelPos < 5) {
   WheelPos -= 2;
   return display.color565(0, 0, 255);
  } else {
   WheelPos -= 5;
   return display.color565(255, 0, 0);
  }
}
// Input a value 0 to 24 to get a color value.
// The colours are a transition r - g - b - back to r.
uint16_t Whel(byte WheelPos) {
  if(WheelPos < 1) {
   return display.color565(255, 0, 0);
  } else if(WheelPos < 2) {
   WheelPos -= 1;
   return display.color565(0, 255, 0);
  } else if(WheelPos < 3) {
   WheelPos -= 2;
   return display.color565(255, 255, 0);
  } else if(WheelPos < 4) {
   WheelPos -= 3;
   return display.color565(255, 0, 255);
  } else if(WheelPos < 5) {
   WheelPos -= 4;
   return display.color565(0, 0, 255);
  } else if(WheelPos < 6) {
   WheelPos -= 5;
   return display.color565(0, 255, 255);
  } else if(WheelPos < 7) {
   WheelPos -= 6;
   return display.color565(255, 0, 255);
  } else if(WheelPos < 8) {
   WheelPos -= 7;
   return display.color565(255, 255, 0);
  } else if(WheelPos < 9) {
   WheelPos -= 8;
   return display.color565(255, 0, 0);
  } else {
   WheelPos -= 9;
   return display.color565(255, 255, 255);
  }
}