ESP32/ESP8266开发板单向一对多ESP-NOW无线通信
简介
本实验通过ESP-NOW无线通信协议实现ESP32开发板向多个ESP32/ESP 8266开发板发送数据。
读取ESP32/ESP8266接收方Receiver的MAC地址
读取ESP32开发板的代码
#include <WiFi.h>
#include <esp_wifi.h>
void readMacAddress(){
uint8_t baseMac[6];
esp_err_t ret = esp_wifi_get_mac(WIFI_IF_STA, baseMac);
if (ret == ESP_OK) {
Serial.printf("%02x:%02x:%02x:%02x:%02x:%02x\n",
baseMac[0], baseMac[1], baseMac[2],
baseMac[3], baseMac[4], baseMac[5]);
} else {
Serial.println("Failed to read MAC address");
}
}
void setup(){
Serial.begin(115200);
WiFi.mode(WIFI_STA);
WiFi.STA.begin();
Serial.print("[DEFAULT] ESP32 Board MAC Address: ");
readMacAddress();
}
void loop(){
}
通过串口读取到接收方ESP32开发板1的MAC地址为：
同样的方式读取到接收方ESP32开发板2的MAC地址为：
读取ESP8266开发板的代码
#include <ESP8266WiFi.h>
void setup(){
Serial.begin(115200);
Serial.println();
Serial.print("ESP Board MAC Address: ");
Serial.println(WiFi.macAddress());
}
void loop(){
}
读取到接收方ESP8266开发板的MAC地址为：
ESP32发送方Sender程序
把ESP32开发板1，ESP开发板2，ESP8266开发板的MAC地址分别填入到下列代码的broadcastAddress1[ ]，broadcastAddress2[ ]，broadcastAddress3[ ]数组中
#include <esp_now.h>
#include <WiFi.h>
// REPLACE WITH YOUR ESP RECEIVER'S MAC ADDRESS
uint8_t broadcastAddress1[] = {0x54, 0x43, 0xb2, 0x7f, 0x00, 0x60};
uint8_t broadcastAddress2[] = {0x34, 0x5f, 0x45, 0xac, 0x16, 0xc0};
uint8_t broadcastAddress3[] = {0xdc, 0x4f, 0x22, 0x23, 0xca, 0x10};
typedef struct test_struct {
int x;
int y;
} test_struct;
esp_now_peer_info_t peerInfo;
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
char macStr[18];
Serial.print("Packet to: ");
// Copies the sender mac address to a string
snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
Serial.print(macStr);
Serial.print(" send status:\t");
Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}
void setup() {
Serial.begin(115200);
WiFi.mode(WIFI_STA);
if (esp_now_init() != ESP_OK) {
Serial.println("Error initializing ESP-NOW");
return;
}
esp_now_register_send_cb(OnDataSent);
// register peer
peerInfo.channel = 0;
peerInfo.encrypt = false;
memcpy(peerInfo.peer_addr, broadcastAddress1, 6);
if (esp_now_add_peer(&peerInfo) != ESP_OK){
Serial.println("Failed to add peer");
return;
}
memcpy(peerInfo.peer_addr, broadcastAddress2, 6);
if (esp_now_add_peer(&peerInfo) != ESP_OK){
Serial.println("Failed to add peer");
return;
}
memcpy(peerInfo.peer_addr, broadcastAddress3, 6);
if (esp_now_add_peer(&peerInfo) != ESP_OK){
Serial.println("Failed to add peer");
return;
}
}
void loop() {
test_struct test;
test_struct test2;
test_struct test3;
test.x = random(0,20);
test.y = random(0,20);
test2.x = random(0,20);
test2.y = random(0,20);
test3.x = random(0,20);
test3.y = random(0,20);
esp_err_t result1 = esp_now_send(
broadcastAddress1,
(uint8_t *) &test,
sizeof(test_struct));
if (result1 == ESP_OK) {
Serial.println("Sent with success");
}
else {
Serial.println("Error sending the data");
}
delay(500);
esp_err_t result2 = esp_now_send(
broadcastAddress2,
(uint8_t *) &test2,
sizeof(test_struct));
if (result2 == ESP_OK) {
Serial.println("Sent with success");
}
else {
Serial.println("Error sending the data");
}
delay(500);
esp_err_t result3 = esp_now_send(
broadcastAddress3,
(uint8_t *) &test3,
sizeof(test_struct));
if (result3 == ESP_OK) {
Serial.println("Sent with success");
}
else {
Serial.println("Error sending the data");
}
delay(2000);
}
ESP32/ESP8266接收方Receiver程序
上传代码到ESP32开发板1和ESP3开发板2
#include <esp_now.h>
#include <WiFi.h>
//Structure example to receive data
//Must match the sender structure
typedef struct test_struct {
int x;
int y;
} test_struct;
//Create a struct_message called myData
test_struct myData;
//callback function that will be executed when data is received
void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
memcpy(&myData, incomingData, sizeof(myData));
Serial.print("Bytes received: ");
Serial.println(len);
Serial.print("x: ");
Serial.println(myData.x);
Serial.print("y: ");
Serial.println(myData.y);
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() != ESP_OK) {
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_register_recv_cb(esp_now_recv_cb_t(OnDataRecv));
}
void loop() {
}
ESP8266开发板接收代码
#include <ESP8266WiFi.h>
#include <espnow.h>
//Structure example to receive data
//Must match the sender structure
typedef struct test_struct {
int x;
int y;
} test_struct;
//Create a struct_message called myData
test_struct 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("x: ");
Serial.println(myData.x);
Serial.print("y: ");
Serial.println(myData.y);
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() {
}
ESP-NOW通信验证
同时给发送方ESP32开发板，接收方ESP32开发板1，接收方ESP32开发板2，接收方ESP8266开发板供电，并打开四个串口助手观察四个开发板的数据收发情况
若接收方都收到数据，发送方ESP32开发板会收到应答信息，串口打印各个MAC地址的接收方数据分发成功：
若有接收方没有收到数据，发送方ESP32开发板会收到应答信息，串口打印对应的MAC地址的接收方数据分发失败：
接收方ESP32开发板1串口打印接收到发送方发过来的随机数据
接收方ESP32开发板2串口打印接收到发送方发过来的随机数据
接收方ESP8266开发板串口打印接收到发送方发过来的随机数据
总结
通过以上例程验证了ESP32/ESP开发板之间单向一对多的ESP-NOW无线通信，接下来的篇章将继续验证多个的ESP32开发板之间实现多对一的ESP-NOW无线通信。
原文地址：https://blog.csdn.net/qq_42250136/article/details/142353849
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