OTTO DIY Class Project

This Instructable covers the basic steps to building and wiring an OTTO DIY robot, using Arduino chip and coding technology.

To build OTTO, you'll need:

-1 small screwdriver, ideally with a long tip for a few hard to reach places. These can be ordered online and used for a large variety of technological maintenance.

-Arduino Nano

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

-Mini usb cable. This should come alongside the Arduino Nano).

-HC-SR04 Ultrasound sensor.

-Mini servo SG90 9g x4. Each of these should come with 2 pointed screws and one small screw, alongside a plastic attachment for the rotor.

6. 5V Buzzer.

7. Female to Female breadboard connectors cable 10cm x5.

8. 4 AA Battery case

9. 1.5V AA batteries x4.

10. Mini cross screwdriver. It's important that the tip be magnetized and the head be long and thin, to aid in attaching a parts with difficult to reach screw holes.

You'll also need to buy or print out the 6 pieces of OTTO's body; these parts can likely either be bought from the OTTO DIY website or printed yourself using the files on the site.

11. 3D printed head.

12. 3D printed body.

13. 3D printed leg x2.

14. 3D printed right foot.

15. 3D printed left foot.

Before we start building, we want to finish setting up the servo motors for future use. This is a simple process of taking the single-direction plastic parts that came with the motors and attaching them to the motor head so that the point is pointing away from the main body of the motor. Once they have been attached, fasten two of them in place with the small screws that came with each motor. The other two will need to be removed once before being fastened into place.

Now we start building OTTO from the feet up. Take the two motors with fastened attachments and the pair of feet, and inspect them for a moment. You should notice that there are indentations that match the shape of the plastic attachments on the motors. Slot the motors into these indentations and fasten them into place using the wider screws, making sure that you keep track of which foot is the left and the right.

Now we switch gears a little bit. In order to properly attach the feet to the legs, the legs need to be attached to the body before the feet can be properly attached. You'll need to take the remaining two motors and the lower body part, and inspect them like the last step. You should notice that the body has a pair of shaped holes that fit the rotor end of the motors. Slot the motors into these holes, and use a pair of screws for each one to fasten them onto the body.

Once they've been fastened, inspect the two leg parts. Notice that there are staggered, rectangular holes in the top and around the middle, as well as an indent almost identical to those in the feet shaped like the motor attachment. First, you'll need to carefully slot these attachments into the indentations and fasten them in with screws. Next, attach the legs to the motors on the body, making sure to align the rectangular openings on both, and fasten the motors to the attachments with screws.

To attach the feet, give them another inspection. You should notice a circular indentation on the opposite side of the foot from the indentation where you attached the motor. There should be a matching nob on one side of each leg piece, and a portion of the leg that roughly matches the rectangular shape of the motor opposite that. Set up the feet so that, if the front of the body is facing away from you, the feet are on the appropriate side. You should then be able to thread the cord from the foot motors through the leg and into the body, using the staggered rectangular holes you aligned earlier. Once the wires have been threaded, you can slide the motor into the legs, so that the knob on the leg slots into the indentation on the foot. There should be a hole on the leg that aligns with a screw hole on the foot motor, and a larger hole opposite it on the leg. sticking your screwdriver through that larger hole, you should be able to fasten the leg to the foot with another screw.

For OTTO's head, we'll need the top body piece, the ultrasound sensor, the Arduino Nano and its extension board, and two screws. To start, carefully slot the Nano into double row of plugs on the center of the extension board, taking care not to bend any of the metal nodes and making sure that the side of the Nano with the mini USB port is on the same side of the extension board as its charging port. Before attaching the board to the head, we need to put the eyes into their slot. This is as easy as lining up the "eyes" of the sensor with the holes in the front of the head, making sure to keep the four metal nodes pointing "down" from the top of the head and the board of the sensor is slotted behind a pair of slightly raised ridges near the eye holes to keep it in place. Once you've secured the sensor into place, you can align the mini USB and charging ports on the Nano board with the holes placed for them in the head piece and fasten the board down with the remaining screws.

For the "eyes" sensor, you'll need four of the female-to-female wires. Being careful to avoid bending any nodes, you'll need to connect the wires to specific nodes on the board: if you number the nodes on the sensor from right to left (assuming the sensor is facing away from you) as 1, 2, 3, and 4, you should connect the nodes as follows: 1->G8, 2->S8, 3->S9, and 4->G11. For the sake of making it easier to see, I've plugged the wiring in and then removed it for the next few steps; but when assembling your own OTTO, you'll need the plug in all the wires and leave them installed.

To give OTTO a voice, all we need to do is connect the wires of the buzzer to the board. All that needs to be done is to carefully connect the black wire to node G10 and the red wire to S10

Giving OTTO legs is a bit complex, as it's easy to get the wires mixed up and plug them into the wrong node. The motors are numbered as follows, with OTTO's "eyes" facing you and using your right and left:

right foot = 2

left foot = 3

right leg = 4

left leg = 5

to wire these to the board, you can simply match the motors as they are numbered with the nodes on the board that share their numbers, making sure that the yellow wire from the motor is pointing away from the "eyes".

To power OTTO, simply connect the red wire from the battery to the VA3 node, and the black wire to the GA2 node.

Once everything has been wired together, all that's left is to carefully connect the head and body together, packing the wires into the empty space and locking it into place with the body's built-in latches.

The final step is to connect OTTO to your computer using the connection cord provided with your Arduino kit, and to upload a code of your choice chosen from the libraries on https://github.com/ottoDIY/OttoDIYLib?tab. Make sure to check the code before you upload it to make sure it references the correct nodes on your board.