ESP to ESP transmission error.

[Jonmurch]

Board

ESP32 Dev Mod

Device Description

two Esp32 dev modules. using one as transmitter and one as receiver to transmit 6 Variables.

Hardware Configuration

they are both empty boards

Version

latest master (checkout manually)

IDE Name

Arduino IDE

Operating System

Windows 10

Flash frequency

80Mhz

PSRAM enabled

no

Upload speed

115200

Description

Transmitter Produces this prompt on loop when running.

Sent with success Last Packet Send Status: Delivery Fail

Receiver Produces this prompt and nothing more

Receiver Setup Started Receiver MAC Address: 00:00:00:00:00:00 ESP-NOW Initialized Peer Added

Sketch

My transmitters Code
{
#include <esp_now.h>
#include <WiFi.h>

// Structure to send data
typedef struct struct_message {
    int base;
    int lowest;
    int bottomMiddle;
    int topMiddle;
    int claw;
    int wrist;
} struct_message;

// Create a struct_message to send data
struct_message myData;

// MAC Address of the receiver ESP32
uint8_t broadcastAddress[] = {0x10, 0x06, 0x1C, 0xB5, 0xAF, 0x96};

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

void setup() {
    // Initialize Serial Monitor
    Serial.begin(115200);
    Serial.println("Transmitter Setup Started");  // Debug message

    // Print own MAC address
    Serial.print("Transmitter MAC Address: ");
    Serial.println(WiFi.macAddress());  // Print the transmitter's MAC address

    // 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;
    }
    Serial.println("ESP-NOW Initialized");  // Debug message

    // Register the send callback
    esp_now_register_send_cb(OnDataSent);

    // Register the 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;
    }
    Serial.println("Peer Added");  // Debug message

    // Initialize servo values
    myData.base = 90;
    myData.lowest = 90;
    myData.bottomMiddle = 90;
    myData.topMiddle = 90;
    myData.claw = 90;
    myData.wrist = 90;
}

void loop() {
    // 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(100); // Minimal delay between sets of data
}
}

My receivers code

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

// Structure to receive data
typedef struct struct_message {
    int base;
    int lowest;
    int bottomMiddle;
    int topMiddle;
    int claw;
    int wrist;
} struct_message;

// Create a struct_message to hold the incoming data
struct_message incomingData;

// Callback when data is received
void OnDataRecv(const esp_now_recv_info *info, const uint8_t *data, int len) {
    Serial.println("Data received callback triggered");  // Debug message
    memcpy(&incomingData, data, sizeof(incomingData));
    Serial.print("Received data from: ");
    char macStr[18];
    snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x", info->src_addr[0], info->src_addr[1], info->src_addr[2], info->src_addr[3], info->src_addr[4], info->src_addr[5]);
    Serial.println(macStr);
    Serial.print("Base: "); Serial.println(incomingData.base);
    Serial.print("Lowest: "); Serial.println(incomingData.lowest);
    Serial.print("Bottom Middle: "); Serial.println(incomingData.bottomMiddle);
    Serial.print("Top Middle: "); Serial.println(incomingData.topMiddle);
    Serial.print("Claw: "); Serial.println(incomingData.claw);
    Serial.print("Wrist: "); Serial.println(incomingData.wrist);
}

void setup() {
    // Initialize Serial Monitor
    Serial.begin(115200);
    Serial.println("Receiver Setup Started");  // Debug message

    // Print own MAC address
    Serial.print("Receiver MAC Address: ");
    Serial.println(WiFi.macAddress());  // Print the receiver's MAC address

    // 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;
    }
    Serial.println("ESP-NOW Initialized");  // Debug message

    // Register the receive callback
    esp_now_register_recv_cb(OnDataRecv);

    // Optionally, you can add the transmitter as a peer
    // This is not required for receiving data, but useful for bidirectional communication
    esp_now_peer_info_t peerInfo;
    uint8_t peerAddress[] = {0xCC, 0x7B, 0x5C, 0x36, 0xD8, 0xFE};
    memcpy(peerInfo.peer_addr, peerAddress, 6);
    peerInfo.channel = 0;
    peerInfo.encrypt = false;

    // Add peer
    if (esp_now_add_peer(&peerInfo) != ESP_OK) {
        Serial.println("Failed to add peer");
        return;
    }
    Serial.println("Peer Added");  // Debug message
}

void loop() {
    // Nothing to do here
    // Data will be received via the callback
}

Debug Message

It seems that the two boards are connected but the receiver is failing to process anything. Any help would be appreciated.

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• [X] I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[SuGlider]

@P-R-O-C-H-Y , It is about ESP-NOW, PTAL. Thanks.

[Jonmurch]

@P-R-O-C-H-Y any input would be appreciated. Never used ESP-NOW so im hoping im on the right track here.

[lbernstone]

There are Arduino libraries for ESP-NOW. You should try them out.
The ESP-IDF functions are documented here. The ESP-IDF example is here

[P-R-O-C-H-Y]

Hi @Jonmurch, as Ibernstone commented you can use our ESP-NOW Arduino library instead of using ESP-IDF APIs. We also have few ready-to-go examples, so you can start with them. For more informations about ESP-NOW library APIs you can take a look to the documentation.