HC-SR04 with ESP32-C3-DevKitM-1

Wiring for the HC-SR04 ultrasonic distance on the ESP32-C3-DevKitM-1 (ESP32-C3, 3.3 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

Check before you power it on

• Supply: 5 V from the 5V pin.
• The HC-SR04 works at 5 V, so its output (ECHO → 3) can reach 5 V. The ESP32-C3-DevKitM-1 pins take only 3.3 V: add a voltage divider (for example 1 kΩ and 2 kΩ) or a level shifter on that wire.

Test code (Arduino)

void setup() {
  Serial.begin(115200);
  pinMode(10, OUTPUT);  // TRIG on 10
  pinMode(3, INPUT);   // ECHO on 3
}

void loop() {
  digitalWrite(10, LOW);  delayMicroseconds(2);
  digitalWrite(10, HIGH); delayMicroseconds(10);
  digitalWrite(10, LOW);
  long us = pulseIn(3, HIGH, 30000);
  Serial.println(us / 58.0);  // distance in cm
  delay(200);
}

Arduino board: esp32:esp32:esp32c3. If uploading does not start, hold BOOT, press and release RST, then release BOOT.

Questions

Which ESP32-C3-DevKitM-1 pins do I use for the HC-SR04?

VCC → 5V, TRIG → 10, ECHO → 3, GND → GND.

Does the HC-SR04 work with the ESP32-C3-DevKitM-1 at 3.3 V?

The HC-SR04 works at 5 V, so its output (ECHO → 3) can reach 5 V. The ESP32-C3-DevKitM-1 pins take only 3.3 V: add a voltage divider (for example 1 kΩ and 2 kΩ) or a level shifter on that wire.

Full ESP32-C3-DevKitM-1 pinout · HC-SR04 ultrasonic distance: all pins and data

The HC-SR04 on other boards

ESP32 DevKit Arduino Mega 2560 R3 Arduino Nano Arduino Uno R3 WeAct Black Pill STM32F411CE ESP32-S3-DevKitC-1 Nordic nRF52840 DK NUCLEO-F401RE Raspberry Pi Pico 2 Raspberry Pi Pico W Raspberry Pi Pico Teensy 4.1

Other parts on the ESP32-C3-DevKitM-1

BME280 BMP280 DHT22 DHT11 SSD1306 OLED MPU6050 DS18B20 WS2812B LED strip SG90 servo Relay module HC-SR501 PIR LCD 1602 I2C INA219 VL53L0X BH1750 MAX30102 RC522 RFID NEO-6M GPS Capacitive soil moisture sensor ADS1115 TM1637 28BYJ-48 stepper L298N Potentiometer Push button LED Joystick module SD card module AHT20