Esp8266 Clock

1#include <Wire.h>
2#include <Adafruit_GFX.h>
3#include <Adafruit_SSD1306.h>
4#include <ESP8266WiFi.h>
5#include <NTPClient.h>
6#include <WiFiUdp.h>
7#include <time.h>
8
9//==== WiFi credentials ====//
10const char* ssid     = "REPLACE_WITH_YOUR_SSID";
11const char* password = "REPLACE_WITH_YOUR_PASSWORD";
12
13//==== OLED size ====//
14#define SCREEN_WIDTH 128
15#define SCREEN_HEIGHT 64
16
17//==== OLED object ====//
18Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
19
20//==== NTP objects ====//
21WiFiUDP ntpUDP;
22NTPClient timeClient(ntpUDP, "pool.ntp.org", 3600);
23
24//==== Weekday names ====//
25String weekDays[7] = {
26  "Sunday", "Monday", "Tuesday", "Wednesday",
27  "Thursday", "Friday", "Saturday"
28};
29
30//==== Month names ====//
31String months[12] = {
32  "January", "February", "March", "April",
33  "May", "June", "July", "August",
34  "September", "October", "November", "December"
35};
36
37void setup() {
38  //==== I2C pins for ESP8266 ====//
39  Wire.begin(14, 12);
40
41  //==== Initialize OLED ====//
42  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
43    while (true);
44  }
45
46  //==== Clear display ====//
47  display.clearDisplay();
48  display.setTextColor(WHITE);
49
50  //==== WiFi connecting message ====//
51  display.setTextSize(1);
52  display.setCursor(0, 0);
53  display.println("Connecting WiFi...");
54  display.display();
55
56  //==== Connect to WiFi ====//
57  WiFi.begin(ssid, password);
58  while (WiFi.status() != WL_CONNECTED) {
59    delay(500);
60  }
61
62  //==== Start NTP client ====//
63  timeClient.begin();
64  timeClient.update();
65}
66
67void loop() {
68  //==== Update time ====//
69  timeClient.update();
70
71  //==== Get raw epoch time ====//
72  time_t rawTime = timeClient.getEpochTime();
73  struct tm* timeInfo = gmtime(&rawTime);
74
75  //==== Extract date values ====//
76  int day   = timeInfo->tm_mday;
77  int month = timeInfo->tm_mon;
78  int year  = timeInfo->tm_year + 1900;
79  int wday  = timeInfo->tm_wday;
80
81  //==== Get formatted time ====//
82  String timeStr = timeClient.getFormattedTime();
83
84  //==== Clear OLED ====//
85  display.clearDisplay();
86
87  //==== Draw big time ====//
88  display.setTextSize(2);
89  display.setCursor(0, 0);
90  display.println(timeStr);
91
92  //==== Draw weekday ====//
93  display.setTextSize(1);
94  display.setCursor(0, 24);
95  display.println(weekDays[wday]);
96
97  //==== Draw date ====//
98  display.setCursor(0, 36);
99  display.print(day);
100  display.print(" ");
101  display.print(months[month]);
102  display.print(" ");
103  display.println(year);
104
105  //==== Update OLED ====//
106  display.display();
107
108  //==== Refresh every second ====//
109  delay(1000);
110}