arduino-projects

Notes

• For Arduino sketches compiled by the Arduino IDE, the sketch folder name and the main .ino filename must match.

• I2C scanner:

  void setup() {
    Serial.begin(9600); // or 115200 for ESP32
    Wire.begin();
  
    for (byte addr = 1; addr < 127; addr++) {
      Wire.beginTransmission(addr);
  
      if (Wire.endTransmission() == 0) {
        Serial.print("Found device at 0x");
        Serial.println(addr, HEX);
      }
    }
  }

Troubleshooting

Avrdude stk500 not in sync

Board: Arduino UNO (ATMEGA328P)

Issue:

Error message on upload after selecting correct board and port:

serial port avrdude: stk500 disable: unknown response= 0x04 does not exist or your board is not connected

Possible cause: digital pins 0 or 1 (used for uploading) or RESET are in use

Solution: Disconnect the pins before upload