3. Cloud-Connected Button Counter

Count each valid press of a physical button and publish the total. The sketch uses the ESP32 internal pull-up and simple contact debounce.

Level: Beginner · Time: 25 minutes

Parts and wiring

ESP32 DevKit V1 and momentary push button

Button terminal	Connection
First side	GPIO 18
Opposite side	GND

With INPUT_PULLUP, the input is HIGH at rest and LOW when pressed.

Complete sketch


#include <PxServ.h>
 
const char* WIFI_SSID = "your_wifi_ssid";
const char* WIFI_PASSWORD = "your_wifi_password";
const char* PXSERV_API_KEY = "your_pxserv_api_key";
const int BUTTON_PIN = 18;
 
PxServ client(PXSERV_API_KEY);
unsigned long pressCount = 0;
bool previousButton = HIGH;
 
void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  PxServ::connectWifi(WIFI_SSID, WIFI_PASSWORD);
  client.setData("button-counter/total", "0");
}
 
void loop() {
  bool currentButton = digitalRead(BUTTON_PIN);
 
  if (previousButton == HIGH && currentButton == LOW) {
    delay(25);
    if (digitalRead(BUTTON_PIN) == LOW) {
      pressCount++;
      PxServ::Callback result = client.setData(
        "button-counter/total",
        String(pressCount)
      );
      Serial.print("Total: ");
      Serial.print(pressCount);
      Serial.print(" | Status: ");
      Serial.println(result.status);
    }
  }
 
  previousButton = currentButton;
  delay(10);
}

Test

Press the button five deliberate times. Serial Monitor and PxServ should both show 5. This teaching counter resets after a reboot. Increase the 25 ms debounce time if one press is counted more than once.