How to transmit and receive current time using RF 433Hz

abel706 · June 8, 2023, 10:08pm

I was doing a project using RF 433Hz to transmit and receive the current time, but i am unable to receive the minute and second at the receiver side. I am using two Arduinos, each of them has their own transmitter and receiver.
Here is my code for the first Arduino to transmit hour, minute and second

#include <DS3231.h>//Memanggil RTC3231 Library
#include <Wire.h>  // i2C Conection Library
#include <LiquidCrystal.h> //Libraries
#include <EEPROM.h>
#include <VirtualWire.h>

LiquidCrystal lcd(12, 11, 6, 5, 4, 3); //Arduino pins to lcd

#define bt_time   A0
#define bt_up     A1
#define bt_down   A2
#define bt_alarm  A3

#define buzzer 8
//rf variables
char *controller;
char *temp;
DS3231  rtc(SDA, SCL);

// Init a Time-data structure
Time  t; //pencacah string time()

int hh = 0, mm = 0, ss = 0, dd = 0, bb = 0, set_day;
int yy = 0;
String Day = "  ";

int AlarmHH  = 21, AlarmMM  = 22, AlarmSS  = 23, setMode = 0, setAlarm = 0, alarmMode=0;

int stop =0, mode=0, flag=0;

//Eeprom Store Variable
uint8_t HH;
uint8_t MM;

 byte bell_symbol[8] = {
        B00100,
        B01110,
        B01110,
        B01110,
        B01110,
        B11111,
        B01000,
        B00100};
byte thermometer_symbol[8] = {
        B00100,
        B01010,
        B01010,
        B01110,
        B01110,
        B11111,
        B11111,
        B01110};


void setup(){
// Setup Serial connection
  Serial.begin(9600);

  rtc.begin(); // memulai koneksi i2c dengan RTC

 pinMode(bt_time,  INPUT_PULLUP);
 pinMode(bt_up,    INPUT_PULLUP);
 pinMode(bt_down,  INPUT_PULLUP);
 pinMode(bt_alarm, INPUT_PULLUP);

 pinMode(buzzer, OUTPUT);

  lcd.createChar(1, thermometer_symbol);
  lcd.createChar(2, bell_symbol);
  
  lcd.begin(16, 2); // Configura lcd numero columnas y filas
  lcd.setCursor(0,0);  //Show "TIME" on the LCD

  lcd.setCursor (0,0);
  lcd.print(" RF-Based Clock ");
  lcd.setCursor (0,1);
  lcd.print("   With Alarm ");
  delay (2000);
  lcd.clear();

stop=EEPROM.read(50);
if(stop==0){  
}else{WriteEeprom ();}

EEPROM.write(50,0); 

ReadEeprom();
vw_set_ptt_inverted(true); // Required for DR3100
vw_set_rx_pin(7);
vw_set_tx_pin(9);
vw_setup(4000); // Bits per sec
Serial.begin(9600);
pinMode(13, OUTPUT);
pinMode(2, OUTPUT);
vw_rx_start(); // Start the receiver PLL running
}

void loop(){  
t = rtc.getTime();
Day = rtc.getDOWStr(1);

if (setMode == 0){
hh = t.hour,DEC;
mm = t.min,DEC;
ss = t.sec,DEC;
dd = t.date,DEC;
bb = t.mon,DEC;
yy = t.year,DEC;
}  

  if(setAlarm==0){
  lcd.setCursor(0,0); 
  lcd.print((hh/10)%10);
  lcd.print(hh % 10); 
  lcd.print(":");
  lcd.print((mm/10)%10);
  lcd.print(mm % 10);
  lcd.print(":");
  lcd.print((ss/10)%10);
  lcd.print(ss % 10);
  lcd.print(" ");  
  if(mode==1){lcd.write(2);}
  else{lcd.print(" ");}   
  lcd.print(" "); 
  lcd.write(1); 
  lcd.print(rtc.getTemp(),0);
  lcd.write(223); 
  lcd.print("C");
  lcd.print("  "); 

  lcd.setCursor(1,1);
  lcd.print(Day);
  lcd.print(" ");
  lcd.print((dd/10)%10);
  lcd.print(dd % 10); 
  lcd.print("/");
  lcd.print((bb/10)%10);
  lcd.print(bb % 10);
  lcd.print("/"); 
  lcd.print((yy/1000)%10);
  lcd.print((yy/100)%10);
  lcd.print((yy/10)%10);
  lcd.print(yy % 10);
  }


setupClock();
setTimer();
delay (100);

blinking();
//Alarm
if (alarmMode==1 && mode==1 && hh==AlarmHH && mm==AlarmMM && ss>=AlarmSS) {
digitalWrite(buzzer, HIGH);
delay (300);
digitalWrite(buzzer, LOW);
}else{digitalWrite(buzzer, LOW);}
delay (100);

Received ();
}

void blinking (){
//BLINKING SCREEN
if (setAlarm <2 && setMode == 1){lcd.setCursor(0,0);  lcd.print("  ");}
if (setAlarm <2 && setMode == 2){lcd.setCursor(3,0);  lcd.print("  ");}
if (setAlarm <2 && setMode == 3){lcd.setCursor(6,0);  lcd.print("  ");}
if (setAlarm <2 && setMode == 4){lcd.setCursor(1,1);  lcd.print("   ");}
if (setAlarm <2 && setMode == 5){lcd.setCursor(5,1);  lcd.print("  ");}
if (setAlarm <2 && setMode == 6){lcd.setCursor(8,1);  lcd.print("  ");}
if (setAlarm <2 && setMode == 7){lcd.setCursor(11,1); lcd.print("    "); }
//Alarm
if (setMode == 0 && setAlarm == 1){lcd.setCursor(6,0); lcd.print("           "); }
if (setMode == 0 && setAlarm == 2){lcd.setCursor(4,1); lcd.print("  "); }
if (setMode == 0 && setAlarm == 3){lcd.setCursor(7,1); lcd.print("  "); }
if (setMode == 0 && setAlarm == 4){lcd.setCursor(10,1);lcd.print("  "); }
}

//Seting Jam ,Tanggal,Alarm/Timer
void setupClock (void) {
   
    if (setMode == 8){
    lcd.setCursor (0,0);
    lcd.print (F("Set Date Finish "));
    lcd.setCursor (0,1);
    lcd.print (F("Set Time Finish "));
    delay (1000);
    rtc.setTime (hh, mm, ss);
    rtc.setDate (dd, bb, yy);  
    lcd.clear();
    setMode = 0;
    }

    if (setAlarm == 5){
    lcd.setCursor (0,0);
    lcd.print (F("Set Alarm Finish"));
    lcd.setCursor (0,1);
    lcd.print (F("-EEPROM Updated-"));
    WriteEeprom();
    delay (2000); 
    lcd.clear();
    setAlarm=0;
    alarmMode=1;
    }
    
 if (setAlarm >0){ alarmMode=0;}
    
 if(digitalRead (bt_time) == 0 && flag==0) {flag=1;
 if(setAlarm>0){setAlarm=5;}
 else{setMode = setMode+1;}
 }
  
 if(digitalRead (bt_alarm) == 0 && flag==0){flag=1;
 if(setMode>0){setMode=8;}
  else{setAlarm = setAlarm+1;} 
  lcd.clear();} 

if(digitalRead (bt_time) == 1 && digitalRead (bt_alarm) == 1){flag=0;}
  
 if(digitalRead (bt_up) == 0){                          
            if (setAlarm<2 && setMode==1)hh=hh+1; 
            if (setAlarm<2 && setMode==2)mm=mm+1;
            if (setAlarm<2 && setMode==3)ss=ss+1;
            if (setAlarm<2 && setMode==4)set_day=set_day+1;
            if (setAlarm<2 && setMode==5)dd=dd+1;
            if (setAlarm<2 && setMode==6)bb=bb+1;
            if (setAlarm<2 && setMode==7)yy=yy+1;
            //Alarm
            if (setMode==0 && setAlarm==1)mode=1;
            if (setMode==0 && setAlarm==2 && AlarmHH<23)AlarmHH=AlarmHH+1;
            if (setMode==0 && setAlarm==3 && AlarmMM<59)AlarmMM=AlarmMM+1;
            if (setMode==0 && setAlarm==4 && AlarmSS<59)AlarmSS=AlarmSS+1;

if(hh>23)hh=0;
if(mm>59)mm=0;
if(ss>59)ss=0;
if(set_day>7)set_day=0;
if(dd>31)dd=0;
if(bb>12)bb=0;
if(yy>2030)yy=2000;
rtc.setDOW(set_day);
 }        

if(digitalRead (bt_down) == 0){                                      
            if (setAlarm<2 && setMode==1)hh=hh-1; 
            if (setAlarm<2 && setMode==2)mm=mm-1;
            if (setAlarm<2 && setMode==3)ss=ss-1;
            if (setAlarm<2 && setMode==4)set_day=set_day-1;
            if (setAlarm<2 && setMode==5)dd=dd-1;
            if (setAlarm<2 && setMode==6)bb=bb-1;
            if (setAlarm<2 && setMode==7)yy=yy-1;
            //Alarm
            if (setMode==0 && setAlarm==1 )mode=0;
            if (setMode==0 && setAlarm==2 && AlarmHH>0)AlarmHH=AlarmHH-1;
            if (setMode==0 && setAlarm==3 && AlarmMM>0)AlarmMM=AlarmMM-1;
            if (setMode==0 && setAlarm==4 && AlarmSS>0)AlarmSS=AlarmSS-1;
if(hh<0)hh=23;
if(mm<0)mm=59;
if(ss<0)ss=59;
if(set_day<0)set_day=7;
if(dd<0)dd=31;
if(bb<0)bb=12;
if(yy<0)yy=2030;
rtc.setDOW(set_day);
 }
 
}

void setTimer (){
  //Alarm
 if (setMode == 0 && setAlarm >0){
  lcd.setCursor (0,0);
  lcd.print("Alarm ");
 if(mode==0){lcd.print("Deactivate");}
        else{lcd.print("Activated ");}
        
  lcd.setCursor (4,1);
  lcd.print((AlarmHH/10)%10);
  lcd.print(AlarmHH % 10);
  lcd.print(":");
  lcd.print((AlarmMM/10)%10);
  lcd.print(AlarmMM % 10);
  lcd.print(":");
  lcd.print((AlarmSS/10)%10);
  lcd.print(AlarmSS % 10);
 }
}

void ReadEeprom () {
  AlarmHH=EEPROM.read(1);
  AlarmMM=EEPROM.read(2);
  AlarmSS=EEPROM.read(3);
  
  mode=EEPROM.read(4); 
}

void WriteEeprom () {
  EEPROM.write(1,AlarmHH);
  EEPROM.write(2,AlarmMM);
  EEPROM.write(3,AlarmSS);
  
  EEPROM.write(4,mode);
}

void Received ()
{
//String timeString = String(t.hour, DEC) + String(t.min, DEC) + String(t.sec, DEC);
//Serial.println(timeString);

//// Convert the current time to a string
//String timeStr = String(t.hour, DEC) + ":" + String(t.min, DEC) + ":" + String(t.sec, DEC);
       
uint8_t buf[VW_MAX_MESSAGE_LEN];
uint8_t buflen = VW_MAX_MESSAGE_LEN;
   Serial.println(controller);

if (vw_get_message(buf, &buflen)) // Non-blocking
{
      if(buf[0]=='1')
      {
      
      digitalWrite(13,HIGH);
      
      controller = "8";
      
     
//       // Send the current time to the receiver
//       vw_send((uint8_t *)timeStr.c_str(), timeStr.length());
//       vw_wait_tx();
       // Print the current time to the Serial Monitor
//       Serial.println(timeStr);
       
//      // Send the current time to the receiver
      char timeStr[20];
      sprintf(timeStr, "%02d:%02d:%02d", t.hour, t.min, t.sec);
      vw_send((uint8_t *)timeStr, strlen(timeStr));
      vw_wait_tx(); 
//      //vw_send((uint8_t *)controller, strlen(controller));
//      //vw_wait_tx();
//      delay(100);
//      vw_send((uint8_t *)timeString.c_str(), strlen(timeString.c_str())); 
//      vw_wait_tx(); 
      delay(1000);
      // Print the current time to the Serial Monitor
      Serial.println(timeStr);
      digitalWrite(2,HIGH);
      
      } 
      else 
      {
      
      digitalWrite(13,LOW);
      
      controller="2";
//      vw_send((uint8_t *)controller, strlen(controller));
//      vw_wait_tx();
//      delay(100);
//      vw_send((uint8_t *)timeStr.c_str(), timeStr.length());
//      vw_wait_tx();
      delay(1000);
      digitalWrite(2,HIGH); 
      }
}
}

Her is the other code used to receive the transmitted hour, minute and second

#include <VirtualWire.h>
#include <Time.h>
char *controller;
char *msg;
const int buttonPin1 = 2;
int buttonState1 = 0;

// Define the pins used by the receiver
const int receiverPin = 12;


void setup()
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(buttonPin1, INPUT);
  
  // Set the receiver pin as an input
  pinMode(receiverPin, INPUT);
  // Initialize the Time library
 // setTime(10, 30, 0, 1, 1, 2023);

  pinMode(11, OUTPUT);
  pinMode(13, OUTPUT);
  vw_set_ptt_inverted(true); //
  vw_set_tx_pin(12);
  vw_set_rx_pin(9);
  vw_setup(4000);// speed of data transfer Kbps
  delay(100);
  vw_rx_start(); // Start the receiver PLL running

}
void loop()
{
  
  buttonState1 = digitalRead(buttonPin1);
  Serial.println(" controller ");
 Serial.println(controller);
  if (buttonState1 == HIGH)
  {

    controller = "1" ;
    vw_send((uint8_t *)controller, strlen(controller));
    vw_wait_tx(); // Wait until the whole message is gone
    delay(100);
    digitalWrite(13, LOW);

  }
  else
  {
    controller = "0" ;
    vw_send((uint8_t *)controller, strlen(controller));
    vw_wait_tx(); // Wait until the whole message is gone
    digitalWrite(13, HIGH);
    
  }

   Serial.println("             ");

   // The loop function runs repeatedly, forever
   // Define the buffer
   char buf[VW_MAX_PAYLOAD];
   // Check if there is a message from the transmitter
   if (vw_get_message(buf, VW_MAX_PAYLOAD)) {
    // Print the message from the transmitter
    for (int i = 0; i < VW_MAX_PAYLOAD; i++) {
      
      Serial.print(" buf[i] ");
      Serial.print(buf[i]);
      int hour = buf[0] * 10 + buf[1];
      int minute = buf[2] * 10 + buf[3];
      int second = buf[4] * 10 + buf[5];
      // Print the hour, minute, and second separately
      Serial.print("Hour: ");
      Serial.println(hour);
       
      Serial.print("Minute: ");
      Serial.println(minute);
      Serial.print("Second: ");
      Serial.println(second);

      Serial.print(" buf[0] ");
      Serial.print(buf[0]);
      Serial.println();
      Serial.print("buf[1]");
      Serial.print(buf[1]);
      Serial.println();
      Serial.print("buf[2]");
      Serial.print(buf[2]);
      Serial.println();
      Serial.print("buf[3]");
      Serial.print(buf[3]);
    }
    Serial.println();
  }

}

jremington · June 8, 2023, 11:31pm

For debugging radio message transmission, it is much easier to get that working starting from a simple example program, before adding all the baggage.

paulpaulson · June 9, 2023, 4:10am

Hello abel706

For wireless projects I recommend the use of the HC12 module.

What are the advantages:

no external functions from a library are needed.
the development of a communication protocol is in your hands
the necessary development steps can be programmed and tested without using the wireless module
the radio module can be easily configured for the project requirements
both transmitter and receiver are contained in one radio module.

Have a nice day and enjoy coding in C++.

abel706 · June 9, 2023, 6:26am

I have tried it again by losing DEC but the result is the same. Here i have formatted the code
first Arduino to transmit hour, minute and second

#include <DS3231.h>//Memanggil RTC3231 Library
#include <Wire.h>  // i2C Conection Library
#include <LiquidCrystal.h> //Libraries
#include <EEPROM.h>
#include <VirtualWire.h>

LiquidCrystal lcd(12, 11, 6, 5, 4, 3); //Arduino pins to lcd

#define bt_time   A0
#define bt_up     A1
#define bt_down   A2
#define bt_alarm  A3

#define buzzer 8
//rf variables
char *controller;
char *temp;
DS3231  rtc(SDA, SCL);

// Init a Time-data structure
Time  t; //pencacah string time()

int hh = 0, mm = 0, ss = 0, dd = 0, bb = 0, set_day;
int yy = 0;
String Day = "  ";

int AlarmHH  = 21, AlarmMM  = 22, AlarmSS  = 23, setMode = 0, setAlarm = 0, alarmMode = 0;

int stop = 0, mode = 0, flag = 0;

//Eeprom Store Variable
uint8_t HH;
uint8_t MM;

byte bell_symbol[8] = {
  B00100,
  B01110,
  B01110,
  B01110,
  B01110,
  B11111,
  B01000,
  B00100
};
byte thermometer_symbol[8] = {
  B00100,
  B01010,
  B01010,
  B01110,
  B01110,
  B11111,
  B11111,
  B01110
};


void setup() {
  // Setup Serial connection
  Serial.begin(9600);

  rtc.begin(); // memulai koneksi i2c dengan RTC

  pinMode(bt_time,  INPUT_PULLUP);
  pinMode(bt_up,    INPUT_PULLUP);
  pinMode(bt_down,  INPUT_PULLUP);
  pinMode(bt_alarm, INPUT_PULLUP);

  pinMode(buzzer, OUTPUT);

  lcd.createChar(1, thermometer_symbol);
  lcd.createChar(2, bell_symbol);

  lcd.begin(16, 2); // Configura lcd numero columnas y filas
  lcd.setCursor(0, 0); //Show "TIME" on the LCD

  lcd.setCursor (0, 0);
  lcd.print(" RF-Based Clock ");
  lcd.setCursor (0, 1);
  lcd.print("   With Alarm ");
  delay (2000);
  lcd.clear();

  stop = EEPROM.read(50);
  if (stop == 0) {
  } else {
    WriteEeprom ();
  }

  EEPROM.write(50, 0);

  ReadEeprom();
  //Set RTC Untuk Pertama kali
  //rtc.setDOW(2);     // Set Day-of-Week to SUNDAY
  //rtc.setTime (00, 9, 50);
  //rtc.setDate(12, 11, 2017);

  //rf pin starting
  vw_set_ptt_inverted(true); // Required for DR3100
  vw_set_rx_pin(7);
  vw_set_tx_pin(9);
  vw_setup(4000); // Bits per sec
  Serial.begin(9600);
  pinMode(13, OUTPUT);
  pinMode(2, OUTPUT);
  vw_rx_start(); // Start the receiver PLL running
}

void loop() {
  t = rtc.getTime();
  Day = rtc.getDOWStr(1);

  if (setMode == 0) {
    hh = t.hour;
    mm = t.min;
    ss = t.sec;
    dd = t.date;
    bb = t.mon;
    yy = t.year;
  }

  if (setAlarm == 0) {
    lcd.setCursor(0, 0);
    lcd.print((hh / 10) % 10);
    lcd.print(hh % 10);
    lcd.print(":");
    lcd.print((mm / 10) % 10);
    lcd.print(mm % 10);
    lcd.print(":");
    lcd.print((ss / 10) % 10);
    lcd.print(ss % 10);
    lcd.print(" ");
    if (mode == 1) {
      lcd.write(2);
    }
    else {
      lcd.print(" ");
    }
    lcd.print(" ");
    lcd.write(1);
    lcd.print(rtc.getTemp(), 0);
    lcd.write(223);
    lcd.print("C");
    lcd.print("  ");

    lcd.setCursor(1, 1);
    lcd.print(Day);
    lcd.print(" ");
    lcd.print((dd / 10) % 10);
    lcd.print(dd % 10);
    lcd.print("/");
    lcd.print((bb / 10) % 10);
    lcd.print(bb % 10);
    lcd.print("/");
    lcd.print((yy / 1000) % 10);
    lcd.print((yy / 100) % 10);
    lcd.print((yy / 10) % 10);
    lcd.print(yy % 10);
  }


  setupClock();
  setTimer();
  delay (100);

  blinking();
  //Alarm
  if (alarmMode == 1 && mode == 1 && hh == AlarmHH && mm == AlarmMM && ss >= AlarmSS) {
    digitalWrite(buzzer, HIGH);
    delay (300);
    digitalWrite(buzzer, LOW);
  } else {
    digitalWrite(buzzer, LOW);
  }
  delay (100);

  Received ();
}

void blinking () {
  //BLINKING SCREEN
  if (setAlarm < 2 && setMode == 1) {
    lcd.setCursor(0, 0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 2) {
    lcd.setCursor(3, 0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 3) {
    lcd.setCursor(6, 0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 4) {
    lcd.setCursor(1, 1);
    lcd.print("   ");
  }
  if (setAlarm < 2 && setMode == 5) {
    lcd.setCursor(5, 1);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 6) {
    lcd.setCursor(8, 1);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 7) {
    lcd.setCursor(11, 1);
    lcd.print("    ");
  }
  //Alarm
  if (setMode == 0 && setAlarm == 1) {
    lcd.setCursor(6, 0);
    lcd.print("           ");
  }
  if (setMode == 0 && setAlarm == 2) {
    lcd.setCursor(4, 1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 3) {
    lcd.setCursor(7, 1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 4) {
    lcd.setCursor(10, 1);
    lcd.print("  ");
  }
}

//Seting Jam ,Tanggal,Alarm/Timer
void setupClock (void) {

  if (setMode == 8) {
    lcd.setCursor (0, 0);
    lcd.print (F("Set Date Finish "));
    lcd.setCursor (0, 1);
    lcd.print (F("Set Time Finish "));
    delay (1000);
    rtc.setTime (hh, mm, ss);
    rtc.setDate (dd, bb, yy);
    lcd.clear();
    setMode = 0;
  }

  if (setAlarm == 5) {
    lcd.setCursor (0, 0);
    lcd.print (F("Set Alarm Finish"));
    lcd.setCursor (0, 1);
    lcd.print (F("-EEPROM Updated-"));
    WriteEeprom();
    delay (2000);
    lcd.clear();
    setAlarm = 0;
    alarmMode = 1;
  }

  if (setAlarm > 0) {
    alarmMode = 0;
  }

  if (digitalRead (bt_time) == 0 && flag == 0) {
    flag = 1;
    if (setAlarm > 0) {
      setAlarm = 5;
    }
    else {
      setMode = setMode + 1;
    }
  }

  if (digitalRead (bt_alarm) == 0 && flag == 0) {
    flag = 1;
    if (setMode > 0) {
      setMode = 8;
    }
    else {
      setAlarm = setAlarm + 1;
    }
    lcd.clear();
  }

  if (digitalRead (bt_time) == 1 && digitalRead (bt_alarm) == 1) {
    flag = 0;
  }

  if (digitalRead (bt_up) == 0) {
    if (setAlarm < 2 && setMode == 1)hh = hh + 1;
    if (setAlarm < 2 && setMode == 2)mm = mm + 1;
    if (setAlarm < 2 && setMode == 3)ss = ss + 1;
    if (setAlarm < 2 && setMode == 4)set_day = set_day + 1;
    if (setAlarm < 2 && setMode == 5)dd = dd + 1;
    if (setAlarm < 2 && setMode == 6)bb = bb + 1;
    if (setAlarm < 2 && setMode == 7)yy = yy + 1;
    //Alarm
    if (setMode == 0 && setAlarm == 1)mode = 1;
    if (setMode == 0 && setAlarm == 2 && AlarmHH < 23)AlarmHH = AlarmHH + 1;
    if (setMode == 0 && setAlarm == 3 && AlarmMM < 59)AlarmMM = AlarmMM + 1;
    if (setMode == 0 && setAlarm == 4 && AlarmSS < 59)AlarmSS = AlarmSS + 1;

    if (hh > 23)hh = 0;
    if (mm > 59)mm = 0;
    if (ss > 59)ss = 0;
    if (set_day > 7)set_day = 0;
    if (dd > 31)dd = 0;
    if (bb > 12)bb = 0;
    if (yy > 2030)yy = 2000;
    rtc.setDOW(set_day);
  }

  if (digitalRead (bt_down) == 0) {
    if (setAlarm < 2 && setMode == 1)hh = hh - 1;
    if (setAlarm < 2 && setMode == 2)mm = mm - 1;
    if (setAlarm < 2 && setMode == 3)ss = ss - 1;
    if (setAlarm < 2 && setMode == 4)set_day = set_day - 1;
    if (setAlarm < 2 && setMode == 5)dd = dd - 1;
    if (setAlarm < 2 && setMode == 6)bb = bb - 1;
    if (setAlarm < 2 && setMode == 7)yy = yy - 1;
    //Alarm
    if (setMode == 0 && setAlarm == 1 )mode = 0;
    if (setMode == 0 && setAlarm == 2 && AlarmHH > 0)AlarmHH = AlarmHH - 1;
    if (setMode == 0 && setAlarm == 3 && AlarmMM > 0)AlarmMM = AlarmMM - 1;
    if (setMode == 0 && setAlarm == 4 && AlarmSS > 0)AlarmSS = AlarmSS - 1;
    if (hh < 0)hh = 23;
    if (mm < 0)mm = 59;
    if (ss < 0)ss = 59;
    if (set_day < 0)set_day = 7;
    if (dd < 0)dd = 31;
    if (bb < 0)bb = 12;
    if (yy < 0)yy = 2030;
    rtc.setDOW(set_day);
  }

}

void setTimer () {
  //Alarm
  if (setMode == 0 && setAlarm > 0) {
    lcd.setCursor (0, 0);
    lcd.print("Alarm ");
    if (mode == 0) {
      lcd.print("Deactivate");
    }
    else {
      lcd.print("Activated ");
    }

    lcd.setCursor (4, 1);
    lcd.print((AlarmHH / 10) % 10);
    lcd.print(AlarmHH % 10);
    lcd.print(":");
    lcd.print((AlarmMM / 10) % 10);
    lcd.print(AlarmMM % 10);
    lcd.print(":");
    lcd.print((AlarmSS / 10) % 10);
    lcd.print(AlarmSS % 10);
  }
}

void ReadEeprom () {
  AlarmHH = EEPROM.read(1);
  AlarmMM = EEPROM.read(2);
  AlarmSS = EEPROM.read(3);

  mode = EEPROM.read(4);
}

void WriteEeprom () {
  EEPROM.write(1, AlarmHH);
  EEPROM.write(2, AlarmMM);
  EEPROM.write(3, AlarmSS);

  EEPROM.write(4, mode);
}

void Received ()
{
  //String timeString = String(t.hour, DEC) + String(t.min, DEC) + String(t.sec, DEC);
  //Serial.println(timeString);

  //// Convert the current time to a string
  //String timeStr = String(t.hour, DEC) + ":" + String(t.min, DEC) + ":" + String(t.sec, DEC);

  uint8_t buf[VW_MAX_MESSAGE_LEN];
  uint8_t buflen = VW_MAX_MESSAGE_LEN;
  Serial.println(controller);

  if (vw_get_message(buf, &buflen)) // Non-blocking
  {
    if (buf[0] == '1')
    {

      digitalWrite(13, HIGH);

      controller = "8";


      //       // Send the current time to the receiver
      //       vw_send((uint8_t *)timeStr.c_str(), timeStr.length());
      //       vw_wait_tx();
      // Print the current time to the Serial Monitor
      //       Serial.println(timeStr);

      //      // Send the current time to the receiver
      char timeStr[20];
      sprintf(timeStr, "%02d:%02d:%02d", t.hour, t.min, t.sec);
      vw_send((uint8_t *)timeStr, strlen(timeStr));
      vw_wait_tx();
      //      //vw_send((uint8_t *)controller, strlen(controller));
      //      //vw_wait_tx();
      //      delay(100);
      //      vw_send((uint8_t *)timeString.c_str(), strlen(timeString.c_str()));
      //      vw_wait_tx();
      delay(1000);
      // Print the current time to the Serial Monitor
      Serial.println(timeStr);
      digitalWrite(2, HIGH);

    }
    else
    {

      digitalWrite(13, LOW);

      controller = "2";
      delay(1000);
      digitalWrite(2, HIGH);

    }
  }
}

Her is the other code used to receive the transmitted hour, minute and second

#include <VirtualWire.h>
#include <Time.h>
char *controller;
char *msg;
const int buttonPin1 = 2;
int buttonState1 = 0;

// Define the pins used by the receiver
const int receiverPin = 12;


void setup()
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(buttonPin1, INPUT);

  // Set the receiver pin as an input
  pinMode(receiverPin, INPUT);
  // Initialize the Time library
  // setTime(10, 30, 0, 1, 1, 2023);

  pinMode(11, OUTPUT);
  pinMode(13, OUTPUT);
  vw_set_ptt_inverted(true); //
  vw_set_tx_pin(12);
  vw_set_rx_pin(9);
  vw_setup(4000);// speed of data transfer Kbps
  delay(100);
  vw_rx_start(); // Start the receiver PLL running

}
void loop()
{

  buttonState1 = digitalRead(buttonPin1);
  Serial.println(" controller ");
  Serial.println(controller);
  if (buttonState1 == HIGH)
  {

    controller = "1" ;
    vw_send((uint8_t *)controller, strlen(controller));
    vw_wait_tx(); // Wait until the whole message is gone
    delay(100);
    digitalWrite(13, LOW);

  }
  else
  {
    controller = "0" ;
    vw_send((uint8_t *)controller, strlen(controller));
    vw_wait_tx(); // Wait until the whole message is gone
    digitalWrite(13, HIGH);

  }

  Serial.println("             ");

  // The loop function runs repeatedly, forever
  // Define the buffer
  char buf[VW_MAX_PAYLOAD];
  // Check if there is a message from the transmitter
  if (vw_get_message(buf, VW_MAX_PAYLOAD)) {
    // Print the message from the transmitter
    for (int i = 0; i < VW_MAX_PAYLOAD; i++) {

      Serial.print(" buf[i] ");
      Serial.print(buf[i]);
      // Extract the hour, minute, and second from the data
      int hour = buf[0] + buf[1] * 10;
      int minute = buf[2] + buf[3] * 10;
      int second = buf[4] + buf[5] * 10;
      // Print the hour, minute, and second
      Serial.print("The time is ");
      Serial.print(hour);
      Serial.print(":");
      Serial.print(minute);
      Serial.print(":");
      Serial.println(second);
    }
    Serial.println();


    
    Serial.print(" buf[0] ");
    Serial.print(buf[0]);
    Serial.println();
    Serial.print("buf[1]");
    Serial.print(buf[1]);
    Serial.println();
    Serial.print("buf[2]");
    Serial.print(buf[2]);
    Serial.println();
    Serial.print("buf[3]");
    Serial.print(buf[3]);

}```

abel706 · June 9, 2023, 6:28am

I have only RF433Hz module I don't have HC12

awneil · June 9, 2023, 7:38am

+1

And, get it working over a wired link before adding all the complexities of radios!

system · December 6, 2023, 7:39am

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.

Topic		Replies	Views
Radio Frequency 433MHz - How can I use it? General Guidance	6	1237	May 5, 2021
help with code rf transmission 433mhz Programming	9	627	May 6, 2021
Arduino not receiving array from RF transmitter 433MHZ General Guidance	4	836	May 5, 2021
433 RF transmitter sending but the receiver is not receiving Networking, Protocols, and Devices	7	4782	May 6, 2021
433MHz RF communication General Guidance	7	1321	May 5, 2021

How to transmit and receive current time using RF 433Hz

Related topics