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#include <SPI.h>
#include <RH_RF95.h>
#define uS_TO_S_FACTOR 1000000 //Conversion factor for micro seconds to seconds
#define TIME_TO_SLEEP 5 //Time ESP32 will go to sleep (in seconds)
RTC_DATA_ATTR int bootCount = 0;
#define RFM95_CS 18
#define RFM95_RST 14
#define RFM95_INT 26
// Change to 434.0 or other frequency, must match RX's freq!
#define RF95_FREQ 915.0
// Singleton instance of the radio driver
RH_RF95 rf95(RFM95_CS, RFM95_INT);
int mypin = 25;
void setup(){
pinMode(mypin, OUTPUT);
delay(1000); //Take some time to open up the Serial Monitor
//Increment boot number and print it every reboot
Serial.println("Boot number: " + String(bootCount));
//Print the wakeup reason for ESP32
//Set timer to 5 seconds
esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
Serial.println("Setup ESP32 to sleep for every " + String(TIME_TO_SLEEP) +
" Seconds");
digitalWrite(mypin, HIGH); // turn the LED on (HIGH is the voltage level)
delay(100); // wait for a second
digitalWrite(mypin, LOW); // turn the LED off by making the voltage LOW
while (!rf95.init()) {
Serial.println("LoRa radio init failed");
Serial.println("Uncomment '#define SERIAL_DEBUG' in RH_RF95.cpp for detailed debug info");
while (1);
Serial.println("LoRa radio init OK!");
// Defaults after init are 434.0MHz, modulation GFSK_Rb250Fd250, +13dbM
if (!rf95.setFrequency(RF95_FREQ)) {
Serial.println("setFrequency failed");
while (1);
Serial.print("Set Freq to: "); Serial.println(RF95_FREQ);
rf95.setTxPower(23, false);
//Go to sleep now
void loop(){}
//Function that prints the reason by which ESP32 has been awaken from sleep
void print_wakeup_reason(){
esp_sleep_wakeup_cause_t wakeup_reason;
wakeup_reason = esp_sleep_get_wakeup_cause();
case 1 : Serial.println("Wakeup caused by external signal using RTC_IO"); break;
case 2 : Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
case 3 : Serial.println("Wakeup caused by timer"); break;
case 4 : Serial.println("Wakeup caused by touchpad"); break;
case 5 : Serial.println("Wakeup caused by ULP program"); break;
default : Serial.println("Wakeup was not caused by deep sleep"); break;
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