automatic cat flap

thingiverse

Here is a rewritten version of the text: Creating an affordable Arduino cat door using minimal hot glue requires these components: - Arduino Nano - Servo motor from RC car steering - 2-4 x 6mm M3 screws - SR04 ultrasonic sensor - 6 x 15mm wall mounting screws (not too thick, around 2mm is ideal) - A thick paperclip (1mm thick) - Your preferred method for attaching the hook to the flap To assemble this project: - Secure the sensor to the angled piece using hot glue. - Insert the M3 screws into the bottom of the nano holder and slide in the Arduino Nano. - Fit the servo motor into the largest piece and secure it with the M3 screws. - Straighten the paperclip. - Bend the paperclip at a 90-degree angle in the middle. - Slot a small amount of the clip's end through both ridges on the hook piece and bend one end closed. - Secure the other end of the clip to one end of the servo horn, ensuring it doesn't rotate. - Attach the hook to the flap securely. - Position the ultrasonic sensor above the flap. - Place the servo motor beside the flap at the top. - Locate the Arduino Nano wherever is most convenient. Programming instructions: - Connect the servo to pin D3. - Configure the ultrasonic sensor's trigger pin to D8 and its echo pin to D9. - Power the servo using the same power source as the Arduino Nano, avoiding the 5V pin.