Otto the Dancing Robot

For my robotics class, my final assessment is to build Otto, an open-source robot that's designed to be easy to assemble and program. In this project, you get hands-on experience with 3D printing, servo motors, Arduino programming, and sensor integration, all while bringing a charming little robot to life.

For the supplies you will need

1. Arduino Nano

2. Arduino NANO Shield I/O Extension Board Expansion XD-212

3. Mini USB cable.

4. HC-SR04 Ultrasound sensor.

5. Mini servo SG90 9g x4 (each one should come with two pointed screws and one small screw).

6. 5V Buzzer.

7. Female to Female breadboard connectors cable, and Male to Male cables

8. 4 AA Battery case

9. 1.5V AA batteries x4.

10. Mini Phillips screwdriver.

11. 3D printed head.

12. 3D printed body.

13. 3D printed leg x2.

14. 3D printed right foot.

15. 3D printed left foot.

16. Wire strippers

17. Electrical tape

STL files provided by Thingiverse

Insert the ultrasound sensor into Otto's head by fitting it into the designated holes on his face. You may need to adjust its position depending on the quality of your print.

Place the Arduino Nano onto the Nano I/O board with both ports facing the same direction, ensuring all pins are correctly aligned. Then, secure the board to the inside top of Otto's head using screws.

So there won't be problems with Otto's movement, the servos must be properly aligned. Attach a connector to the servo and turn it entirely to the left, then entirely to the right, and finally back to the center. The goal is to find the midpoint, where the servo can rotate equally in both directions. Once centered, leave the servos in that position. This ensures that when power is applied, it will return to its default position. Do this to all of the servos.

Insert the servo into the body, ensuring it is aligned in its designated position. After that, mount the servo to the body using the provided screws.

Insert a connector into the foot at its designated location. Then attach the servo to the connector inside the foot. Once inserted, secure the servo in place by placing a screw on the outside of the foot. You'll want to repeat this process for each foot.

Remove a T connector and trim it to fit snugly inside the groove of the leg. Once it is inserted, attach the leg with the connector to the servo gear and secure it using a screw. Repeat for the other leg.

Guide the servo cables for the feet through the leg until you reach the bottom of the body, where there is a slit that will allow you to pull the wires through. The foot has a divot that fits over a bump, which will hold the foot in place. After positioning the foot, use screws to secure it more firmly.

For wiring up Otto, I used a diagram from hackaday.io. I first started with the ultrasound sensor, using female to female wires I inserted the first wire to the middle peg in row 10, second wire goes to bottom peg on row 9, third wire goes on bottom peg on row 8 and the last wire goes on the first from the top peg on row 8. Secondly, I wired up the servos, plugging the left foot into the number 5 spot, the left leg into number 3, the right foot into number 4, and the right leg into number 2. For the battery, I spliced two male and female wires together, then inserted the red wire into the V+ terminal (VIN) and the black wire into the ground terminal (ground). Lastly, for the speaker, I spliced two female-to-female wires to the speaker wires and inserted the positive wire into the bottom peg on row 10 and the ground wire into the first peg on row 10. My nano board was preloaded with code, but you can also obtain the code from Ottodiy or GitHub and use the Arduino IDE to install it using a USB cable with Otto's nano.

Connect the power, then place Otto's head on his body, securing all the cables in place. Then have a dance party!!!