I hope I'm in the right forum.
Im trying to transmit a message via ESP NOW protocol from a DoIT ESP 32 to a WeMos D1Mini. (ESP32 to ESP 8266)
I used the code from randomnerdtutorials.com.
Code for sender as follows:
#include <esp_now.h>
#include <WiFi.h>
// REPLACE WITH YOUR RECEIVER MAC Address
uint8_t broadcastAddress[] = {0xE8, 0x9F, 0x6D, 0x8F, 0xDF, 0x56};
// Structure example to send data
// Must match the receiver structure
typedef struct struct_message {
char a[32];
int b;
float c;
bool d;
} struct_message;
// Create a struct_message called myData
struct_message myData;
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 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;
}
}
void loop() {
// Set values to send
strcpy(myData.a, "THIS IS A CHAR");
myData.b = random(1,20);
myData.c = 1.2;
myData.d = 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");
}
delay(2000);
}
Code for receiver as follows:
#include <ESP8266WiFi.h>
#include <espnow.h>
// Structure example to receive data
// Must match the sender structure
typedef struct struct_message {
char a[32];
int b;
float c;
bool d;
} struct_message;
// Create a struct_message called myData
struct_message myData;
// Callback function that will be executed when data is received
void OnDataRecv(uint8_t * mac, uint8_t *incomingData, uint8_t 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("Bool: ");
Serial.println(myData.d);
Serial.println();
}
void setup() {
// Initialize Serial Monitor
Serial.begin(115200);
// Set device as a Wi-Fi Station
WiFi.mode(WIFI_STA);
// Init ESP-NOW
if (esp_now_init() != 0) {
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_set_self_role(ESP_NOW_ROLE_SLAVE);
esp_now_register_recv_cb(OnDataRecv);
}
void loop() {
}
With this code, I do not get any error when compiling or uploading the program.
Serial monitor of ESP 32 shows Data sent successfully but Delivery failed.
Serial monitor of WeMos is empty.
I tried adding this code under Init ESP-NOW
else if (esp_now_init() ==0){
Serial.println("Initialization successful");
}
This returns "Error initializing ESP-NOW" on the serial monitor.
However, on changing the code to
else
{
Serial.println("Initialization succesful");
}
It returns "Initialization successful" on the serial monitor.
Other than this, I have also tried
WiFi.disconnect(true);
and
ESP.eraseConfig();
both of which change absolutely nothing.
I am confused whether my ESP_now_init is active or not or whether something else is wrong.
However, on changing the roles (ie. WeMos as transmitter and ESP32 as receiver, ESP NOW works properly. (Code obtained from randomnerdtutorials.com)
I am on SDK2.2.1 with the latest arduino core.
I do not have any other ESP boards to try out, so that is not an option either.
Thanks for the help.
