//Most of the relevant code came from https://randomnerdtutorials.com/esp-now-esp32-arduino-ide/
//To get the MAC address of the ESP go to their site and they have a program that will display it on the serial monitor
// You need two ESP with WIFI and it will send packets from ESP1 to ESP2 and ESP2 to ESP1 the packet count is adjustable and the
// time between packet "SETS" is adjustable
#include <esp_now.h>
#include <WiFi.h>
//#include <HardwareSerial.h> // To connect to the TEENSY 4.1
//HardwareSerial MySerial1(1); // To connect to the TEENSY 4.1
// You need two ESP with WIFI
// REPLACE WITH YOUR RECEIVER MAC Address - Make sure it is the MAC address to the ESP you are Sending THE DATA TO...
uint8_t WIFI_broadcastAddress[] = {XXXX, XXXX, XXXX, XXXX, XXXX, XXXX}; //
// Structure example to send data
// Must match the receiver structure
typedef struct WIFI_Incoming_Struct {
char WIFI_Incoming_Packet[100];
} WIFI_Incoming_Struct;
// Create a struct_message called WIFI_Incoming_Packet_Struct_Variable
WIFI_Incoming_Struct WIFI_Incoming_Packet_Struct_Variable;
// Structure example to send data
// Must match the receiver structure
typedef struct WIFI_Outgoing_Struct {
char WIFI_Outgoing_Packet[100];
} WIFI_Outgoing_Struct;
// Create a struct_message called WIFI_Outgoint_Packet_Struct_Variable
WIFI_Outgoing_Struct WIFI_Outgoing_Packet_Struct_Variable;
esp_now_peer_info_t peerInfo;
/////////////////////////////////////////////////////////////////////////////////////
int WIFI_IncomingPacketCount = 0;
int WIFI_OutboundPacketCount = 0;
//int WIFI_Incoming_IntBufferArray[101] = {};
String WIFI_Incoming_StringBufferArray[101] = {};
int WIFI_Incoming_StringBufferArray_IndexSize = 100;
int WIFI_Incoming_StringBuffer_Write_Index = 0;
int WIFI_Incoming_StringBuffer_Last_Write_Index_SinceRead = 0;
int WIFI_Incoming_StringBuffer_Read_Index = 0;
int WIFI_SendPacket_SwitchCase = 0;
bool WIFI_OnDataSent_Fail_Flag = 0; // 1 = Fail
uint64_t WIFITimerToResend = 0;
int WIFITimerToResend_TimeBetweenTries_Millis = 500; // Adjusts the time between sets
int WIFITimerToResend_TryNumber = 1;
int WIFITimerToResend_MaxTries = 20; // Adjust this to send more or less packets in a SET
int SwitchCase = 0;
uint32_t MillisTimer1 = 0;
uint32_t MillisTimer2 = 0;
uint32_t MillisTimerDifference = 0;
int PacketCounter = 1;
int PacketstoSendBeforeNextBreak = 0;
int PacketsBeforeBreak = 30;
int TimeBeforePacketSendResumes_Millis = 3000;
uint32_t PacketSendResumeTimer = 0;
int PacketNumber = 1;
String PacketString;
char PacketStringCharArray[100];
void setup() {
// Init Serial Monitor
Serial.begin(115200);
// And configure MySerial1 on pins RX=D9, TX=D10 To connect to the TEENSY 4.1
// MySerial1.begin(115200, SERIAL_8N1, 9, 10);
// MySerial1.print("MySerial1");
// Set device as a Wi-Fi Station
WiFi.mode(WIFI_STA);
// Init ESP-NOW
if (esp_now_init() != ESP_OK) {
Serial.println("Error initializing ESP-NOW");
return;
}
// Once ESPNow is successfully Init, we will register for Send CB to
// get the status of Trasnmitted packet
esp_now_register_send_cb(esp_now_send_cb_t(OnDataSent));
// Once ESPNow is successfully Init, we will register for recv CB to
// get recv packer info
esp_now_register_recv_cb(esp_now_recv_cb_t(OnDataRecv));
// Register peer
memcpy(peerInfo.peer_addr, WIFI_broadcastAddress, 6);
peerInfo.channel = 0;
peerInfo.encrypt = false;
// Add peer
if (esp_now_add_peer(&peerInfo) != ESP_OK) {
Serial.println("Failed to add peer");
return;
}
delay(5000); // to give me time to get the serial monitor up on my computer
} // End Void Setup
//////////////////////////////////////////////////////////////////////////
void loop() {
//Print incoming data
if (WIFI_Incoming_StringBuffer_Read_Index != WIFI_Incoming_StringBuffer_Write_Index) {
Serial.print(WIFI_IncomingPacketCount);
Serial.print(" ");
Serial.println(WIFI_Incoming_StringBufferArray[WIFI_Incoming_StringBuffer_Read_Index]);
if (WIFI_Incoming_StringBuffer_Read_Index >= WIFI_Incoming_StringBufferArray_IndexSize) {
WIFI_Incoming_StringBuffer_Read_Index = 0;
} else {
WIFI_Incoming_StringBuffer_Read_Index++;
} // End Else
WIFI_IncomingPacketCount++;
} // End if(WIFI_Incoming_StringBuffer_Last_Write_Index_SinceRead != WIFI_Incoming_StringBuffer_Write_Index)
// Send data
if(PacketSendResumeTimer <= millis()) {
if(PacketCounter > PacketstoSendBeforeNextBreak) {
PacketstoSendBeforeNextBreak = PacketCounter + PacketsBeforeBreak;
PacketSendResumeTimer = millis() + TimeBeforePacketSendResumes_Millis;
} else {
PacketString = String(PacketNumber) + " " + "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
PacketString.toCharArray(PacketStringCharArray, PacketString.length() + 1);
strcpy(WIFI_Outgoing_Packet_Struct_Variable.WIFI_Outgoing_Packet, PacketStringCharArray);
WIFI_SendPacket();
PacketCounter++;
}// End else
} // End if(PacketSendResumeTimer <= millis())
//delay(51);
} // End Void Loop
void WIFI_SendPacket() {
switch (WIFI_SendPacket_SwitchCase) {
case 0: {
// Send message via ESP-NOW
esp_err_t result = esp_now_send(WIFI_broadcastAddress, (uint8_t *)&WIFI_Outgoing_Packet_Struct_Variable, sizeof(WIFI_Outgoing_Packet_Struct_Variable));
if (result == ESP_OK) {
WIFI_SendPacket_SwitchCase = 1;
// Serial.print("Out PC");
//Serial.println(WIFI_OutboundPacketCount);
} else {
WIFI_SendPacket_SwitchCase = 2;
Serial.println("Error sending the data OUT");
} // end else
break; // case 0
} // End Case 0
case 1: {
if (WIFI_OnDataSent_Fail_Flag == 0) {
WIFI_SendPacket_SwitchCase = 0;
PacketNumber++;
} else {
WIFI_SendPacket_SwitchCase = 2;
} // End else
break; // case 1
} // End case 1
case 2: {
if (WIFITimerToResend < millis()) {
esp_err_t result = esp_now_send(WIFI_broadcastAddress, (uint8_t *)&WIFI_Outgoing_Packet_Struct_Variable, sizeof(WIFI_Outgoing_Packet_Struct_Variable));
if (result == ESP_OK) {
WIFI_SendPacket_SwitchCase = 1;
} else {
Serial.println("Error Trying to resend the data");
} // end else
WIFITimerToResend = (WIFITimerToResend_TimeBetweenTries_Millis * WIFITimerToResend_TryNumber) + millis();
if (WIFITimerToResend_TryNumber > WIFITimerToResend_MaxTries) {
WIFITimerToResend_TryNumber = WIFITimerToResend_MaxTries;
} else {
WIFITimerToResend_TryNumber++;
} // End else
} // End if(WIFITimerToResend < millis())
break; // case 2
} // End case 2
} // End switch(WIFI_SendPacket_SwitchCase)
} // End void WIFI_SendPacket()
// callback when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
if (status == ESP_NOW_SEND_FAIL) {
WIFI_OnDataSent_Fail_Flag = 1;
} else {
WIFI_OnDataSent_Fail_Flag = 0;
} //end else
} // End void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status)
// callback function that will be executed when data is received
void OnDataRecv(const uint8_t *mac, const uint8_t *incomingData, int len) {
memcpy(&WIFI_Incoming_Packet_Struct_Variable, incomingData, sizeof(WIFI_Incoming_Packet_Struct_Variable));
if (WIFI_Incoming_StringBuffer_Write_Index >= WIFI_Incoming_StringBufferArray_IndexSize) {
WIFI_Incoming_StringBuffer_Write_Index = 0;
} else {
WIFI_Incoming_StringBuffer_Write_Index++;
} // End else
WIFI_Incoming_StringBufferArray[WIFI_Incoming_StringBuffer_Write_Index] = String(WIFI_Incoming_Packet_Struct_Variable.WIFI_Incoming_Packet);
} //End void OnDataRecv(const uint8_t *mac, c.....
