Build Instructions

Collapse

• 1

  Tools and Materials

  The following tools and materials were used for this project:

  Tools:

  • 3D printer - The whole body of the robot is 3D printed. Several hours of 3d printing were needed for building the whole structure;
  • PLA filament - White and black PLA filaments where used for printing the body;
  • Screw driver - Most of the parts are connected using bolts;
  • Super glue - Some of the parts were attached using super glue;
  • Pliers and cutters
  • Solder iron and wire

  Electronics:

  • Arduino Uno (link / link) - It's used as the main controller of the robot. It sends signals to the motors and communicates with the WiFi module;
  • ESP8266-01 (link / link)- It's used as a 'WiFi modem'. It receives signals from the control interface to be performed by the Arduino Uno;
  • SG90 servomotors (x6) (link / link) - Four servos were used for the arms, and two for head movements;
  • DC motors with reduction and rubber wheels (x2) (link / link) - They allow the robot to travel small distances;
  • L298N dual channel H-bridge (x1) (link / link) - It converts Arduino digital outputs into power voltages to the motors;
  • 16 channels servo controller (link / link) - With this board one can control several servomotors using only two Arduino outputs;
  • MAX7219 8x8 LED display (x4) (link / link) - They are used as the face of the robot;
  • Micro USB cable - Used for uploading the code;
  • Female-female jumper wires (some);
  • Male-female jumper wires (some);
  • Smartphone - A Motorola 4.3" Moto E smartphone was used. Others with similar size might work as well;
  • 18650 battery (x2) (link) - They were used to power the Arduino and other peripherals;
  • 18650 battery holder (x1) (link / link) - They hold the batteries in place;
  • 1N4001 diodes (x2)
  • 10 kohm resistores (x3)
  • 20mm on/off switch (x1)
  • Protoshield (link) - It helps wiring up the circuit.

  Mechanics:

  • Ball wheels (x2)
  • M2x6mm bolts (+-70)
  • M2x10mm bolts (+-20)
  • M2x1.5mm nuts (x10)
  • M3x40mm bolts (x4)
  • M3x1.5mm nuts (x4)

  The links above are a suggestion of where you can find the items used in this tutorial and support the development of this project. Feel free to search for them elsewhere and buy at your favorite local or online store.

  Did you know you can buy the Anet A8 for only $155.99 at Gearbest? Get yours: http://bit.ly/2kqVOdO

• 2

  3D Printing

  The robot structure was entirely produced with 3D printing using Autodesk Fusion 360. In order to enable the production of robot replicas in makerspaces or fab labs, where the maximum time of use of the printers is crucial, the design of the robot was divided in pieces smaller than three hours of printing each. The set of parts is glued or bolted for body mounting.

  The model is composed of 36 different parts. Most of them was printed without supports, with 10% infill.

  • Head top (right/left)
  • Head bottom (right/left)
  • Head side caps (right/left)
  • Face back plate
  • Face front plate
  • Neck axis 1
  • Neck axis 2
  • Neck axis 3
  • Neck center
  • Arm (right/left)
  • Shoulder (right/left)
  • Shoulder cup (right/left)
  • Shoulder cap (right/left)
  • Arm axis (right/left)
  • Bust (rigth/left)
  • Chest (right/left/front)
  • Wheels (right/left)
  • Base
  • Phone holder
  • Back (right/left)
  • Knobs (right/left)
  • Locker (right/left)

  The procedure for mouting the robot is described on the following steps.

  You can download all the stl files on the following websites:

  • https://www.thingiverse.com/thing:2765192
  • https://pinshape.com/items/42221-3d-printed-joy-robot-robo-da-alegria
  • https://www.youmagine.com/designs/joy-robot-robo-da-alegria
  • https://cults3d.com/en/3d-model/gadget/joy-robot-robo-da-alegria
  • https://www.myminifactory.com/object/55782

  This is a experimental prototype. Some of the parts need some improvements (for later updates of the project). There are some known issues:

  • Interference between the wiring of some servos and the shoulder;
  • Friction between the head and the bust;
  • Friction between the wheels and the structure;
  • The hole for some screws is too tight, and need to be enlarged with a drilling bit or a hobby knife.

  If you don't have a 3D printer, here are some things you can do:

  • Ask a friend to print it for you;
  • Find a hacker/maker space nearby. The model was divided in several parts, so that each parts individually takes less than four hours to print. Some hacker/maker spaces will only charge your for the materials used;
  • Buy your own 3D printer. You can find an Anet A8 for only $155.99 at Gearbest. Get yours: http://bit.ly/2kqVOdO
  • Interested in purchasing a DIY Kit? If enough people are interested, I might be offering a DIY kits on Tindie.com. If you would like one, send me a message.

• 3

  Overview on the Circuits

  The robot is controlled using an Arduino Uno at it's core. The Arduino interfaces an ESP8266-01 module, which is used to remote control the robot over an Wi-Fi network.

  An 16-channel servo controller is connected to the Arduino using I2C communication and controls 6 servomotors (two for the neck and two for each arm). An array of five 8x8 LED matrices is powered and controlled by the Arduino. Four Arduino's digital outputs are used for the control of two DC motors, using an h-bridge.

  The circuits are powered using two USB power banks: one for the motors and one for the Arduino. I've tryed to power the whole robot using a signle power pack. But ESP8266 used to lost connection due to spikes when DC motors turned on/off.

  The chest of the robot has a smartphone. It's used to broadcast video and audio to/from the control interface, hosted on an ordinary computer. It can also send commands to the ESP6288, thus controlling the body of the robot itself.

  One might notice that the components used here might not be optimised for its purpose. A NodeMCU might be used instead of the Arduino + ESP8266 combination, for instance. A Rapsberry Pi with a camera would replace the smartphone and controll the motors as well. It's even possible to use an Android smartphone as the "brain" for your robot. That's true... An Arduino Uno was choosed because it's very accessible and easy to use for everyone. By the time we started this project, ESP and Raspberry Pi board where still relatively expensive in the place we live... once we wanted to build and inexpensive robot, Arduino boards where the best choise at that moment.

View all 16 instructions