B4R Tutorial ESP32 NOW Example (inline C)

The code was taken from this site: https://randomnerdtutorials.com/esp-now-esp32-arduino-ide/

You need 2 ESP32's (one is the sender, the other one the receiver). Modify the code to have multiple receivers/senders and to get/set the variables from B4R

Output is something like this:

AppStart
7C:9E:BD:E4:15:50
Sent with success
Last Packet Send Status:    Delivery Success

Sender:

Note: Replace the MAC address to the one of the receiver

#Region Project Attributes
    #AutoFlushLogs: True
    #CheckArrayBounds: True
    #StackBufferSize: 600
    #DefineExtra: #include "rCore.h"
#End Region
'Ctrl+Click to open the C code folder: ide://run?File=%WINDIR%\System32\explorer.exe&Args=%PROJECT%\Objects\Src

Sub Process_Globals
    Public Serial1 As Serial
    
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    RunNative("StartESPNow", Null)
End Sub

#if C


#include <esp_now.h>
#include <WiFi.h>

esp_now_peer_info_t peerInfo;

// REPLACE WITH YOUR RECEIVER MAC Address
uint8_t broadcastAddress[] = {0x24, 0x62, 0xAB, 0xFF, 0xCB, 0x30};
//24:62:AB:FF:CB:30
// Structure example to send data
// Must match the receiver structure
typedef struct struct_message {
  char a[32];
  int b;
  float c;
  String d;
  bool e;
} struct_message;

// Create a struct_message called myData
struct_message myData;

// callback when data is sent
  void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}



void StartESPNow(B4R::Object* o) {
   WiFi.mode(WIFI_STA);
   Serial.println(WiFi.macAddress());
  
  // 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(OnDataSent);
 
  // Register peer
  //esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, 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;
  }
 
 
  strcpy(myData.a, "THIS IS A CHAR");
  myData.b = random(1,20);
  myData.c = 1.2;
  myData.d = "Hello";
  myData.e = false;

  // Send message via ESP-NOW
  esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));
  
  if (result == ESP_OK) {
    Serial.println("Sent with success");
  }
  else {
    Serial.println("Error sending the data");
  }

  
}

#End If

Receiver:

Output:

AppStart
24:62:AB:FF:CB:30
Bytes received: 56
Char: THIS IS A CHAR
Int: 14
Float: 1.20
String: Hello
Bool: 0

#Region Project Attributes
    #AutoFlushLogs: True
    #CheckArrayBounds: True
    #StackBufferSize: 600
    #DefineExtra: #include "rCore.h"
#End Region
'Ctrl+Click to open the C code folder: ide://run?File=%WINDIR%\System32\explorer.exe&Args=%PROJECT%\Objects\Src

Sub Process_Globals
    Public Serial1 As Serial
    
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    RunNative("StartESPReceiver", Null)
End Sub

#if C


#include <esp_now.h>
#include <WiFi.h>

esp_now_peer_info_t peerInfo;

// REPLACE WITH YOUR RECEIVER MAC Address
uint8_t broadcastAddress[] = {0x7C, 0x9E, 0xBD, 0xE4, 0x15, 0x50};

// Structure example to receive data
// Must match the sender structure
typedef struct struct_message {
    char a[32];
    int b;
    float c;
    String d;
    bool e;
} struct_message;

// Create a struct_message called myData
struct_message myData;

// callback function that will be executed when data is received
void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
  memcpy(&myData, incomingData, sizeof(myData));
  Serial.print("Bytes received: ");
  Serial.println(len);
  Serial.print("Char: ");
  Serial.println(myData.a);
  Serial.print("Int: ");
  Serial.println(myData.b);
  Serial.print("Float: ");
  Serial.println(myData.c);
  Serial.print("String: ");
  Serial.println(myData.d);
  Serial.print("Bool: ");
  Serial.println(myData.e);
  Serial.println();
}



void StartESPReceiver(B4R::Object* o) {
   WiFi.mode(WIFI_STA);
   Serial.println(WiFi.macAddress());
  
  // 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 recv CB to
  // get recv packer info
  esp_now_register_recv_cb(OnDataRecv);

  
}

#End If