Super Simple Minimalistic Easy ESPNOW
Posted: Sun Aug 07, 2022 12:28 pmWe are working on a project that needs communication between ESP8266s. We used ESPNOW to send MAC addresses between our ESPs. Our goal is to share this and give others a simple and easy way to use ESPNOW on the ESP8266. We look forward to reading your comments on this topic.
Code: Select all
/*
Super Simple Minimalist Easy ESPNOW
This is an easy way to communicate between ESP8266s.
*no error checking
*no encryption
*broadcast only
*unlimited number of transceivers
*Six bits+Five bytes of sender id and/or payload(two low order bits of first byte are reserved)
*250 bytes of optional payload
Aaron Chand
Tim Hayward
License: MIT License
*/
#include <ESP8266WiFi.h>
#include <espnow.h>
uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
/* Optional Custom MAC Address
uint8_t newMACAddress[] = {0x44, 0x44, 0x44, 0x44, 0x44, 0x44};
*/
bool OkayToSend; //Sending is Complete
typedef struct struct_message {
//structure example to send data //must match the receiver structure
char a[250];
} struct_message;
struct_message myData; // create a data structure called myData
char s [32];
void OnDataRecv(uint8_t * mac, uint8_t *incomingData, uint8_t len) { //receive data
memcpy(&myData, incomingData, sizeof(myData));
char macStr[18];
Serial.print("Data received");
snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
Serial.print(macStr);
Serial.print("\t");
Serial.println(myData.a);
}
void OnDataSent(uint8_t *mac_addr, uint8_t sendStatus) {
OkayToSend = true;
}
void setup() {
Serial.begin(115200); //Init Serial Monitor
Serial.println("Super Simple Minimalist Easy ESPNOW");
WiFi.mode(WIFI_STA); //Set Device as a WiFi Station
WiFi.disconnect();
/* Uncomment to Set Custom MAC Address
wifi_set_macaddr(STATION_IF, &newMACAddress[0]);
*/
esp_now_init(); //init ESPNOW
esp_now_set_self_role(ESP_NOW_ROLE_COMBO);
esp_now_register_send_cb(OnDataSent);
esp_now_register_recv_cb(OnDataRecv);
esp_now_add_peer(broadcastAddress, ESP_NOW_ROLE_COMBO, 1, NULL, 0); //add peer
}
void loop() {
strcpy(myData.a,"THIS IS THE PAYLOAD"); //set values to send
while (!OkayToSend){}
OkayToSend = false;
esp_now_send(0, (uint8_t*) &myData, sizeof(myData)); // send a message
delay(100);
}