// EspnowController.ino
// a minimal program derived from
//
HarringayMakerSpace/ESP-Now
// This is the program that sends the data. (The Controller)
//=============
#include <ESP8266WiFi.h>
extern "C" {
#include <espnow.h>
}
// this is the MAC Address of the slave which receives the data
uint8_t remoteMac[] = {0x36, 0x33, 0x33, 0x33, 0x33, 0x33};
#define WIFI_CHANNEL 4
// must match the slave struct
struct __attribute__((packed)) DataStruct {
char text[32];
unsigned long time;
};
DataStruct myData;
unsigned long lastSentMillis;
unsigned long sendIntervalMillis = 1000;
unsigned long sentMicros;
unsigned long ackMicros;
unsigned long lastBlinkMillis;
unsigned long fastBlinkMillis = 200;
unsigned long slowBlinkMillis = 700;
unsigned long blinkIntervalMillis = slowBlinkMillis;
byte ledPin = 14;
//==============
void setup() {
Serial.begin(115200); Serial.println();
Serial.println("Starting EspnowController.ino");
WiFi.mode(WIFI_STA); // Station mode for esp-now controller
WiFi.disconnect();
Serial.printf("This mac: %s, ", WiFi.macAddress().c_str());
Serial.printf("slave mac: %02x%02x%02x%02x%02x%02x", remoteMac[0], remoteMac[1], remoteMac[2], remoteMac[3], remoteMac[4], remoteMac[5]);
Serial.printf(", channel: %i\n", WIFI_CHANNEL);
if (esp_now_init() != 0) {
Serial.println("*** ESP_Now init failed");
while(true) {};
}
esp_now_set_self_role(ESP_NOW_ROLE_CONTROLLER);
esp_now_add_peer(remoteMac, ESP_NOW_ROLE_SLAVE, WIFI_CHANNEL, NULL, 0);
esp_now_register_send_cb(sendCallBackFunction);
strcpy(myData.text, "Hello World");
Serial.print("Message "); Serial.println(myData.text);
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, HIGH);
delay(500);
digitalWrite(ledPin, LOW);
Serial.println("Setup finished");
}
//==============
void loop() {
sendData();
blinkLed();
}
//==============
void sendData() {
if (millis() - lastSentMillis >= sendIntervalMillis) {
lastSentMillis += sendIntervalMillis;
myData.time = millis();
uint8_t bs[sizeof(myData)];
memcpy(bs, &myData, sizeof(myData));
sentMicros = micros();
esp_now_send(NULL, bs, sizeof(myData)); // NULL means send to all peers
Serial.println("sent data");
}
}
//==============
void sendCallBackFunction(uint8_t* mac, uint8_t sendStatus) {
ackMicros = micros();
Serial.print("Trip micros "); Serial.println(ackMicros - sentMicros);
Serial.printf("Send status = %i", sendStatus);
Serial.println();
Serial.println();
if (sendStatus == 0) {
blinkIntervalMillis = fastBlinkMillis;
}
else {
blinkIntervalMillis = slowBlinkMillis;
}
}
//================
void blinkLed() {
if (millis() - lastBlinkMillis >= blinkIntervalMillis) {
lastBlinkMillis += blinkIntervalMillis;
digitalWrite(ledPin, ! digitalRead(ledPin));
}
}
