93 lines
3.0 KiB
Arduino
93 lines
3.0 KiB
Arduino
|
/**
|
||
|
|
ESPNOW - Basic communication - Slave
|
||
|
|
Date: 26th September 2017
|
||
|
|
Author: Arvind Ravulavaru <https://github.com/arvindr21>
|
||
|
|
Purpose: ESPNow Communication between a Master ESP32 and multiple ESP32 Slaves
|
||
|
|
Description: This sketch consists of the code for the Slave module.
|
||
|
|
Resources: (A bit outdated)
|
||
|
|
a. https://espressif.com/sites/default/files/documentation/esp-now_user_guide_en.pdf
|
||
|
|
b. http://www.esploradores.com/practica-6-conexion-esp-now/
|
||
|
|
|
||
|
|
<< This Device Slave >>
|
||
|
|
|
||
|
|
Flow: Master
|
||
|
|
Step 1 : ESPNow Init on Master and set it in STA mode
|
||
|
|
Step 2 : Start scanning for Slave ESP32 (we have added a prefix of `slave` to the SSID of slave for an easy setup)
|
||
|
|
Step 3 : Once found, add Slave as peer
|
||
|
|
Step 4 : Register for send callback
|
||
|
|
Step 5 : Start Transmitting data from Master to Slave(s)
|
||
|
|
|
||
|
|
Flow: Slave
|
||
|
|
Step 1 : ESPNow Init on Slave
|
||
|
|
Step 2 : Update the SSID of Slave with a prefix of `slave`
|
||
|
|
Step 3 : Set Slave in AP mode
|
||
|
|
Step 4 : Register for receive callback and wait for data
|
||
|
|
Step 5 : Once data arrives, print it in the serial monitor
|
||
|
|
|
||
|
|
Note: Master and Slave have been defined to easily understand the setup.
|
||
|
|
Based on the ESPNOW API, there is no concept of Master and Slave.
|
||
|
|
Any devices can act as master or salve.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <esp_now.h>
|
||
|
|
#include <WiFi.h>
|
||
|
|
|
||
|
|
#define CHANNEL 1
|
||
|
|
|
||
|
|
// Init ESP Now with fallback
|
||
|
|
void InitESPNow() {
|
||
|
|
if (esp_now_init() == ESP_OK) {
|
||
|
|
Serial.println("ESPNow Init Success");
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
Serial.println("ESPNow Init Failed");
|
||
|
|
// Retry InitESPNow, add a counte and then restart?
|
||
|
|
// InitESPNow();
|
||
|
|
// or Simply Restart
|
||
|
|
ESP.restart();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// config AP SSID
|
||
|
|
void configDeviceAP() {
|
||
|
|
String Prefix = "Slave:";
|
||
|
|
String Mac = WiFi.macAddress();
|
||
|
|
String SSID = Prefix + Mac;
|
||
|
|
String Password = "123456789";
|
||
|
|
bool result = WiFi.softAP(SSID.c_str(), Password.c_str(), CHANNEL, 0);
|
||
|
|
if (!result) {
|
||
|
|
Serial.println("AP Config failed.");
|
||
|
|
} else {
|
||
|
|
Serial.println("AP Config Success. Broadcasting with AP: " + String(SSID));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void setup() {
|
||
|
|
Serial.begin(115200);
|
||
|
|
Serial.println("ESPNow/Basic/Slave Example");
|
||
|
|
//Set device in AP mode to begin with
|
||
|
|
WiFi.mode(WIFI_AP);
|
||
|
|
// configure device AP mode
|
||
|
|
configDeviceAP();
|
||
|
|
// This is the mac address of the Slave in AP Mode
|
||
|
|
Serial.print("AP MAC: "); Serial.println(WiFi.softAPmacAddress());
|
||
|
|
// Init ESPNow with a fallback logic
|
||
|
|
InitESPNow();
|
||
|
|
// Once ESPNow is successfully Init, we will register for recv CB to
|
||
|
|
// get recv packer info.
|
||
|
|
esp_now_register_recv_cb(OnDataRecv);
|
||
|
|
}
|
||
|
|
|
||
|
|
// callback when data is recv from Master
|
||
|
|
void OnDataRecv(const uint8_t *mac_addr, const uint8_t *data, int data_len) {
|
||
|
|
char macStr[18];
|
||
|
|
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("Last Packet Recv from: "); Serial.println(macStr);
|
||
|
|
Serial.print("Last Packet Recv Data: "); Serial.println(*data);
|
||
|
|
Serial.println("");
|
||
|
|
}
|
||
|
|
|
||
|
|
void loop() {
|
||
|
|
// Chill
|
||
|
|
}
|