#include <Wire.h>`
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <WiFi.h>
#include "time.h"
#include "sntp.h"
const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";
const char* ntpServer1 = "pool.ntp.org";
const char* ntpServer2 = "time.nist.gov";
const long gmtOffset_sec = 3600;
const int daylightOffset_sec = 3600;
int hrs=0;
int mins=0;
int secs=0;
Adafruit_SSD1306 display(128, 64, &Wire, -1);
const int NUM_POINTS = 60;
const int RADIUS = 28;
int pointsX[NUM_POINTS];
int pointsY[NUM_POINTS];
void setup() {
Serial.begin(115200);
// set notification call-back function
sntp_set_time_sync_notification_cb(timeavailable);
sntp_servermode_dhcp(1); // (optional)
configTime(gmtOffset_sec, daylightOffset_sec, ntpServer1, ntpServer2);
//connect to WiFi
Serial.printf("Connecting to %s ", ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println(" CONNECTED");
/***************************************************/
display.begin(SSD1306_SWITCHCAPVCC, 0x3C); //initialize the display with I2C address 0x3C
display.clearDisplay(); //clear the display buffer
display.display(); //update the display
for (int i = 0; i < NUM_POINTS; i++) {
pointsX[i] = 64 + RADIUS * cos(i * 6.28 / NUM_POINTS);
pointsY[i] = 32 + RADIUS * sin(i * 6.28 / NUM_POINTS);
}
}
void loop() {
setLocalTime();
//calculate the angle for each hand
float secAngle = map(secs, 0, 60, 0, 360);
float minAngle = map(mins, 0, 60, 0, 360);
float hrAngle = map(hrs, 1, 12, 30, 360);
//calculate the positions of the hands
int hrX = 64 + (RADIUS - 11) * cos((hrAngle - 90) * PI / 180);
int hrY = 32 + (RADIUS - 11) * sin((hrAngle - 90) * PI / 180);
int minX = 64 + (RADIUS - 6) * cos((minAngle - 90) * PI / 180);
int minY = 32 + (RADIUS - 6) * sin((minAngle - 90) * PI / 180);
int secX = 64 + (RADIUS)*cos((secAngle - 90) * PI / 180);
int secY = 32 + (RADIUS)*sin((secAngle - 90) * PI / 180);
display.clearDisplay(); //clear the display buffer
//draw the clock face
display.drawCircle(64, 32, 32, WHITE); //Draw a Center Point
//Draw 12 Clock points
for (int i = 0; i < NUM_POINTS; i += 5) {
display.fillCircle(pointsX[i], pointsY[i], 1, WHITE);
}
//Display Numbers 12-3-6-9
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
for (int i = 12; i > 1; i -= 3) {
float angle = map(i, 1, 12, 30, 360);
int xPos = 64 + (RADIUS - 7) * cos((angle - 90) * PI / 180) - 3;
int yPos = 32 + (RADIUS - 7) * sin((angle - 90) * PI / 180) - 3;
display.setCursor(xPos, yPos);
display.print(i);
}
//draw the hour hand
display.drawLine(64, 32, hrX, hrY, WHITE);
//draw the minute hand
display.drawLine(64, 32, minX, minY, WHITE);
//draw the Second hand
//display.drawLine(64, 32, secX, secY, WHITE);
display.drawCircle(secX, secY, 2, WHITE);
//update the display
display.display();
delay(1000);
}
void setLocalTime() {
struct tm timeinfo;
if (!getLocalTime(&timeinfo)) {
Serial.println("No time available (yet)");
return;
}
Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
hrs = timeinfo.tm_hour;
mins = timeinfo.tm_min;
secs = timeinfo.tm_sec;
}
// Callback function (get's called when time adjusts via NTP)
void timeavailable(struct timeval* t) {
Serial.println("Got time adjustment from NTP!");
setLocalTime();
}
this is the code it is one of the ssd1306 examples