// https://docs.wokwi.com/guides/esp32-wifi
/*
Definition of struct tm:
Member Type Meaning Range
tm_sec int seconds after the minute 0-61*
tm_min int minutes after the hour 0-59
tm_hour int hours since midnight 0-23
tm_mday int day of the month 1-31
tm_mon int months since January 0-11
tm_year int years since 1900
tm_wday int days since Sunday 0-6
tm_yday int days since January 1 0-365
tm_isdst int Daylight Saving Time flag
*/
#include "time.h"
#include <WiFi.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <PubSubClient.h>
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);
#define NTP_SERVER "pool.ntp.org"
#define UTC_OFFSET 28800 // 3600*8 = 28800
#define UTC_OFFSET_DST 0
unsigned long lastMsg = 0;
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.mqtt-dashboard.com";
WiFiClient espClient;
PubSubClient client(espClient);
String Time1="";
char jsonChar1[50];
char jsonChar2[50];
void spinner() {
static int8_t counter = 0;
const char* glyphs = "\xa1\xa5\xdb";
LCD.setCursor(15, 1);
LCD.print(glyphs[counter++]);
if (counter == strlen(glyphs)) {
counter = 0;
}
}
void printLocalTime() {
struct tm timeinfo;
if (!getLocalTime(&timeinfo)) {
LCD.setCursor(0, 1);
LCD.println("Connection Err");
return;
}
LCD.setCursor(8, 0);
LCD.println(&timeinfo, "%H:%M:%S");
LCD.setCursor(0, 1);
LCD.println(&timeinfo, "%d/%m/%Y %Z");
}
void printLocalTime2(){
struct tm timeinfo;
if(!getLocalTime(&timeinfo)){
Serial.println("Failed to obtain time");
return;
}
Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
int current_hour = timeinfo.tm_hour;
int current_min = timeinfo.tm_min;
int current_sec = timeinfo.tm_sec;
Time1 = String (current_hour)+":"+ String (current_min)+":"+ String (current_sec);
Serial.println(Time1);
int current_year = 1900+ timeinfo.tm_year;
int current_mon = timeinfo.tm_mon;
int current_mday = timeinfo.tm_mday;
Time1 = Time1 + " " + String (current_year)+"/"+ String (current_mon)+"/"+ String (current_mday);
Serial.println(Time1);
Serial.print("Day of week: ");
Serial.println(&timeinfo, "%A");
Serial.print("Month: ");
Serial.println(&timeinfo, "%B");
Serial.print("Day of Month: ");
Serial.println(&timeinfo, "%d");
Serial.print("Year: ");
Serial.println(&timeinfo, "%Y");
Serial.print("Hour: ");
Serial.println(&timeinfo, "%H");
Serial.print("Hour (12 hour format): ");
Serial.println(&timeinfo, "%I");
Serial.print("Minute: ");
Serial.println(&timeinfo, "%M");
Serial.print("Second: ");
Serial.println(&timeinfo, "%S");
Serial.println("Time variables");
char timeHour[3];
strftime(timeHour,3, "%H", &timeinfo);
Serial.println(timeHour);
char timeWeekDay[10];
strftime(timeWeekDay,10, "%A", &timeinfo);
Serial.println(timeWeekDay);
Serial.println();
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}}
void reconnect() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
if (client.connect(clientId.c_str())) {
Serial.println("Connected");
client.publish("alex9ufo/ThinkIOT/Publish", "Welcome");
client.subscribe("alex9ufo/ThinkIOT/Subscribe");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}}
}
void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
LCD.init();
LCD.backlight();
LCD.setCursor(0, 0);
LCD.print("Connecting to ");
LCD.setCursor(0, 1);
LCD.print("WiFi ");
WiFi.begin("Wokwi-GUEST", "", 6);
while (WiFi.status() != WL_CONNECTED) {
delay(250);
spinner();
}
Serial.println("");
Serial.println("WiFi connected");
Serial.print("IP address: ");
Serial.println(WiFi.localIP());
LCD.clear();
LCD.setCursor(0, 0);
LCD.println("Online");
LCD.setCursor(0, 1);
LCD.println("Updating time...");
configTime(UTC_OFFSET, UTC_OFFSET_DST, NTP_SERVER);
}
void loop() {
printLocalTime();
delay(250);
if (!client.connected()) {
reconnect();
}
client.loop();
unsigned long now = millis();
if (now - lastMsg > 12000) {
printLocalTime2();
lastMsg = now;
Time1.toCharArray(jsonChar1, Time1.length()+1);
client.publish("alex9ufo/ThinkIOT/NTPTime1", jsonChar1);
}
}
Node-Red 程式
[
{
"id": "9741629b8510891f",
"type": "mqtt in",
"z": "2ded2ffb8cb68caa",
"name": "",
"topic": "alex9ufo/ThinkIOT/NTPTime1",
"qos": "1",
"datatype": "auto-detect",
"broker": "603bb104.d6134",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 200,
"y": 300,
"wires": [
[
"70f6524c6b60447d"
]
]
},
{
"id": "70f6524c6b60447d",
"type": "ui_text",
"z": "2ded2ffb8cb68caa",
"group": "ed796d698b021723",
"order": 2,
"width": 0,
"height": 0,
"name": "",
"label": "收到 NTP的訊息",
"format": "{{msg.payload}}",
"layout": "row-spread",
"className": "",
"x": 460,
"y": 300,
"wires": []
},
{
"id": "603bb104.d6134",
"type": "mqtt-broker",
"name": "",
"broker": "broker.mqtt-dashboard.com",
"port": "1883",
"clientid": "",
"autoConnect": true,
"usetls": false,
"compatmode": false,
"protocolVersion": "4",
"keepalive": "15",
"cleansession": true,
"birthTopic": "",
"birthQos": "0",
"birthPayload": "",
"birthMsg": {},
"closeTopic": "",
"closePayload": "",
"closeMsg": {},
"willTopic": "",
"willQos": "0",
"willPayload": "",
"willMsg": {},
"userProps": "",
"sessionExpiry": ""
},
{
"id": "ed796d698b021723",
"type": "ui_group",
"name": "NTP_Time",
"tab": "b83c5c221c74411b",
"order": 2,
"disp": true,
"width": "6",
"collapse": false,
"className": ""
},
{
"id": "b83c5c221c74411b",
"type": "ui_tab",
"name": "Wokwi",
"icon": "dashboard",
"order": 121,
"disabled": false,
"hidden": false
}
]
