bonjour Sara; je souhaite créer un réseau emaillé en utilisant les cartes ESP32, ces dernières doivent envoyer leurs données provenant des différents capteurs à une autre carte ESP32 (Master) afin que le master puisse à son tour envoyer à distance sur un serveur Web pour afficher les differentes informations des capteurs ( DHT11,MQ135,MQ2…) sur le DASHBOARD de notre système de controle. Mais je suis un peu bloqué,pourriez-vous me dire si mon système peut etre realisable et si oui; pourriez-vous m’aider à le concretiser ? Cordialement ! Glos

I’m working on something like this right now. The hard part of it is if you want to have an expanded wireless range that requires each mesh node to pass messages along to the main “controller”. For the first 60 seconds after starting up the controller stores the unique nodeIDs from any incoming messages in an array. We need that so that we can wait for an update from each “data sender” before we broadcast a “sleep” message to them.
My data sender nodes are sending the battery voltage and temperature readings.
When we have an update from all nodes we broadcast a sleep message with the duration (so I can change that from the controller).
When the data sender nodes receive that message they do 2 mesh.update(); calls to try to make sure all nodes get the message.

Here’s what I have so far in the controller’s receivedCallback

void receivedCallback( uint32_t from, String &msg ) {
Serial.printf("Received from %u msg=%s\n", from, msg.c_str());
JSONVar myObject = JSON.parse(msg.c_str());
bool found = false;
for (int i = 0; i < nodeCount; i++) {
if (from == nodeIDs[i][0]) {
if (nodeIDs[i][1] == 0) {
nodeIDs[i][1] = 1;
updateCount++;
}
found = true;
}
}
if (found == false) {
nodeIDs[nodeCount][0] = from;
nodeIDs[nodeCount][1] = 1;
nodeCount++;
updateCount++;
Serial.println("Found new node");
}

}


Hi.
I don’t think that would be a problem.
But, if you want to make sure it receives all readings, maybe it’s better to send an acknowledged message from the receiver to the sender.

Regards,
Sara

Thank you so much for your great work! I love randomnerdtutorials 🙂

It is now updated and compatible with 3.0.0.
Regards,
Sara

Carlo I had the same issue and now solved I’ve solved ,
I was using in arduino ide the board definition 3.0.0 -rc that seems to be not compatible with the intruction format “esp_now_register_recv_cb(OnDataRecv);”.
I’ve installed the version 2.0.14 and now is working.

Should be great update the code for the new board version or place an allert in the comments.

exit status 1

Compilation error: invalid conversion from ‘void ()(const uint8_t, const uint8_t*, int)’ {aka ‘void ()(const unsigned char, const unsigned char*, int)’} to ‘esp_now_recv_cb_t’ {aka ‘void ()(const esp_now_recv_info, const unsigned char*, int)’} [-fpermissive]

Have you idea if there is any issues with such levels of libraries ?
Thanks Roberto