ESP_NOW error when restarted with a flag

Official Hardware Nano Family Nano ESP32
1

Hi,

I am trying to use esp_now to send data. I created a flag variable to start and stop the data transfer. It works fine during initialization but throws an error(Error sending data) when the flag is resetted. I tried to reinitialize the esp_now in the callback function, but did not work. Code attached below

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

// REPLACE WITH YOUR RECEIVER MAC Address
uint8_t broadcastAddress[] = {0x08, 0x3A, 0xF2, 0xA9, 0xB9, 0xC8};

// Structure example to send data
// Must match the receiver structure
typedef struct struct_message
{
  // char a[30];
  float battery_voltage;
  float shunt_voltage;
  int time;
} struct_message;

// Create a struct_message called myData
struct_message myData;

static bool flag = true;

esp_now_peer_info_t peerInfo;

// 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 OnDataRecv(const uint8_t *mac_addr, const uint8_t *incomingdata, int len)
{

  Serial.print("Command received ");
  memcpy(&flag, incomingdata, sizeof(incomingdata));
  Serial.println(flag);

  if (flag)
  {

    if (esp_now_init() != ESP_OK)
    {
      Serial.println("Error initializing ESP-NOW");
      return;
    }
    esp_now_register_send_cb(OnDataSent);

    // Register peer
    memcpy(peerInfo.peer_addr, broadcastAddress, 6);
    peerInfo.channel = 0;
    peerInfo.encrypt = false;
  }
}

void setup()
{
  // Init Serial Monitor
  Serial.begin(115200);

  // 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(OnDataSent);

  // Register peer
  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;
  }

  esp_now_register_recv_cb(OnDataRecv);
}

void loop()
{

  if (flag)
  {
    // Set values to send
    myData.battery_voltage = analogRead(35);
    myData.shunt_voltage = analogRead(32);
    myData.time = millis();

    delay(500);

    // 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");
    }
    delay(1000);
  }
}```





Kindly point out whats wrong in the code. Thanks