ESP32 WiFi painlessmesh network Application

Scheme:

Use four ESP32 to construct a mesh network, when one of them connect with each other the build-in blue led will light up flashing. 

Reference

https://randomnerdtutorials.com/esp-mesh-esp32-esp8266-painlessmesh/

Open painlessmesh sample Code:

Modify painlessmesh Task:

Use multitask function, add a led task at core 0 to show The led blinks when there is a new connection

code show:

//************************************************************

// this is a simple example that uses the painlessMesh library

//

// 1. sends a silly message to every node on the mesh at a random time between 1 and 5 seconds

// 2. prints anything it receives to Serial.print

//

//

//************************************************************

#include "painlessMesh.h"

#define   MESH_PREFIX     "Peter1015"

#define   MESH_PASSWORD   "No18141814"

#define   MESH_PORT       5555

Scheduler userScheduler; // to control your personal task

painlessMesh  mesh;

//------------led task--------------------------------------

#define LED_BUILTIN 2

TaskHandle_t hled;

void vLEDFlashTask(void *pvParameters);

// User stub

void sendMessage() ; // Prototype so PlatformIO doesn't complain

Task taskSendMessage( TASK_SECOND * 1 , TASK_FOREVER, &sendMessage );

/*--------------------------------------------------*/

void vLEDFlashTask(void *pvParameters) // This is a task.

{

  (void)pvParameters;

  // initialize digital LED_BUILTIN on pin 2 as an output.

  Serial.print(F("LEDTask at core:"));

  Serial.println(xPortGetCoreID());

  pinMode(LED_BUILTIN, OUTPUT);

  for (;;) // A Task shall never return or exit.

  {

    digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)

    vTaskDelay(200);

    digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW

    vTaskDelay(200);

  }

}

void sendMessage() {

  String msg = "Hello from node ";

  msg += mesh.getNodeId();

  mesh.sendBroadcast( msg );

  taskSendMessage.setInterval( random( TASK_SECOND * 1, TASK_SECOND * 5 ));

}

// Needed for painless library

void receivedCallback( uint32_t from, String &msg ) {

  Serial.printf("startHere: Received from %u msg=%s\n", from, msg.c_str());

}

void newConnectionCallback(uint32_t nodeId) {

    Serial.printf("--> startHere: New Connection, nodeId = %u\n", nodeId);

    vTaskResume(hled);

}

void changedConnectionCallback() {

  Serial.printf("Changed connections\n");

}

void nodeTimeAdjustedCallback(int32_t offset) {

    Serial.printf("Adjusted time %u. Offset = %d\n", mesh.getNodeTime(),offset);

}

void setup() {

  Serial.begin(115200);

  xTaskCreatePinnedToCore(

    vLEDFlashTask, "LEDTask" // A name just for humans

    ,

    1024 // This stack size can be checked & adjusted by reading the Stack Highwater

    ,

    NULL, 2 // Priority, with 3 (configMAX_PRIORITIES - 1) being the highest, and 0 being the lowest.

    ,

    &hled //handle

    ,

    0);  //core 0

  pinMode(LED_BUILTIN, INPUT);

  vTaskSuspend(hled);

 

//mesh.setDebugMsgTypes( ERROR | MESH_STATUS | CONNECTION | SYNC | COMMUNICATION | GENERAL | MSG_TYPES | REMOTE ); // all types on

  mesh.setDebugMsgTypes( ERROR | STARTUP );  // set before init() so that you can see startup messages

  mesh.init( MESH_PREFIX, MESH_PASSWORD, &userScheduler, MESH_PORT );

  mesh.onReceive(&receivedCallback);

  mesh.onNewConnection(&newConnectionCallback);

  mesh.onChangedConnections(&changedConnectionCallback);

  mesh.onNodeTimeAdjusted(&nodeTimeAdjustedCallback);

  userScheduler.addTask( taskSendMessage );

  taskSendMessage.enable();

}

void loop() {

  // it will run the user scheduler as well

  mesh.update();

}

Achievement Demonstration:

YouTube: