Programmation avancée

   Les bases de la programmation arduino avec esp8266/esp32

Imprimer
Détails
Catégorie : Programmation avancée
Affichages : 1054

 1°/ Structuration d'un sketch (= programme)

2°/ Lire/écrire sur les pins GPIO

 

 

 

void setup() {
  pinMode(D3, OUTPUT);
  pinMode(D2, INPUT);
  ...
}

 

Exemple (esp8266):

int val = analogRead(A0); // read value from 0 to 1023 (= 0V to 3.3V)
byte b = digitalRead(D2);
digitalWrite(D3,HIGH); // on an esp8266, D3 now outputs 3.3V
digitalWrite(D3,LOW); // on an esp8266, D3 now outputs 0V

 Exemple (esp32) :

int val = analogRead(33); // read value from 0 to 4095 (= 0V to 3.3V)
byte b = digitalRead(8);
analogWrite(25, 1234); // write 1234 on pin 25 of an esp32, which corresponds to 3.3*1234/4096 = 0.9942V
digitalWrite(4,HIGH); // on an esp32, 4 now outputs 3.3V
digitalWrite(4,LOW); // on an esp32, 4 now outputs 0V

 

3°/ Communication série

...
void setup() {
  Serial.begin(115200); // initialize serial connection at 115200 bauds
  Serial.println("hello");
  ...
}

 

Remarques : 

 

 

4°/ Interruptions

Exemple : pin D3 d'une carte basée sur un esp8266

volatile byte state;
...
void ICACHE_RAM_ATTR mycallback() {
  state = digitalRead(D3);
  ...
}
...
void setup() {
  ...
  attachInterrupt(digitalPinToInterrupt(D3), mycallback, CHANGE);
  ...
}
Remarques: 
 
5°/ Pulse Width Modulation (PWM)

Duty Cycle Examples

 

 

 

 

Exemple sur une esp8266/arduino :

analogWriteRange(100);
analogWirteFreq(10000); // 10KHz
analogWrite(D3,13); // duty cycle = 13/range = 13/100 =>  13%

 

Remarques :

 

6°/ A propos de la consommation électrique

 

 

 

 

 

7°/ Mise en veille

7.1°/ sur l'esp8266

Exemple (esp8266): 

uint32_t bootcount;
void setup() {
  Serial.begin(115200);
  ...
  ESP.rtcUserMemoryRead(0, &bootcount, sizeof(bootcount));
  Serial.println(bootcount);
  ...
  bootcount++;
  ESP.rtcUserMemoryWrite(0, &bootcount, sizeof(bootcount));
  ...
}
void loop() {
  ...
  ESP.deepSleep(5000000); // sleep 5s, (=5000000µs)
}

 

7.2°/ sur l'esp32

Exemple (esp32):

RTC_DATA_ATTR int bootCount = 0;

// print the reason by which ESP32 has been awaken from sleep
void print_wakeup_reason(){
  esp_sleep_wakeup_cause_t wakeup_reason;
  wakeup_reason = esp_sleep_get_wakeup_cause();
  switch(wakeup_reason)  {
    case ESP_SLEEP_WAKEUP_EXT0 : Serial.println("Wakeup caused by external signal using RTC_IO"); break;
    case ESP_SLEEP_WAKEUP_EXT1 : Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
    case ESP_SLEEP_WAKEUP_TIMER : Serial.println("Wakeup caused by timer"); break;
    case ESP_SLEEP_WAKEUP_TOUCHPAD : Serial.println("Wakeup caused by touchpad"); break;
    case ESP_SLEEP_WAKEUP_ULP : Serial.println("Wakeup caused by ULP program"); break;
    default : Serial.printf("Wakeup was not caused by deep sleep: %d\n",wakeup_reason); break;
  }
}

void setup() {
  Serial.begin(115200);
  ++bootCount;
  Serial.println(bootCount);
  print_wakeup_reason();
  // configure pin 33 as external wakeup source
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_33,1); //1 = High, 0 = Low
  // configure deep sleep timer
  esp_sleep_enable_timer_wakeup(5000000); // time in µ-seconds
}

void loop() {
  delay(1000);
  Serial.println("Going to sleep now");
  esp_deep_sleep_start();
  Serial.println("This will never be printed");
}