Introduction: 12V Pink Truck Car With Adjustable Handlebar Joystick Steering Mod

About: Students at Wichita State University run a program that modifies off-the-shelf ride-on toy cars for kids with disabilities. Our cars feature more technical builds with joysticks and arduinos. We post our instr…

Step 1: Materials List

Parts Needed

  • 12V Vehicle*
  • 1” PVC Pipe
  • PVC T-joint
  • Flexible PVC neck joint
  • KY033 Black White Line Hunting Sensor*
  • Thumbstick Joysticks
  • 1” PVC mount x2
  • 3” Threaded machine screws w/nuts
  • Five wire telephone cable
  • Wire nuts and set screws
  • On/Off flip switches x2
  • Pool noodle
  • ¾” PVC mount x4
  • ATTTINY 85 x2
  • Bread Board
  • 6V 4 Wheeler Hot Pink Car
  • Wire Connectors (Assorted Sizes)
  • Velcro

Tools Needed

  • Wire Strippers
  • PVC cutters
  • 18V drill w/drill bits
  • Screwdriver
  • Soldering iron w/solder

*Click For Purchase Link

Step 2: Kill Switch Installation

  1. Under the seat, cut the red wire that connects the motor to the battery.
  2. Insert Female Crimp. Connect the wires from kill switch to both ends of the wire attaching two male crimp to the ends of the wires.
  3. After connecting the wires to the kill switch, let the wires run through the outside of the back vehicle

Step 3: Handlebar Creation

  1. Flexible PVC neck adaptor is secured to the 1” PVC stem
  2. ¾” PVC pipe is cut into three smaller pieces: 3” x1, 8” x2
  3. ¾” PVC pipe pieces combined with PVC T-joint as shown
  4. Outer layer of 5 wire telephone cable stripped off, threaded through PVC stem through hole

Step 4: Handlebar Mounting

  1. Drill used to create and ream hole just under handlebar shaft placement for wire to go through
  2. 1” PVC pipe cut to length of 14”
  3. 1” PVC mounts x2 used to secure 1” PVC pipe to car via 3” machine screws (see next picture)
  4. Set screws placed to complete mounting and hold PVC

Step 5: Wiring the Handlebar

  1. The wires that were threaded through the handlebar stem then need to have approximately 1” stripped from either end of them.
  2. Set the thumbstick joystick, using screws, onto the top of the handle bar and connect the wires from the joystick to a colored wire from the 5 colored telephone cable.
    • Here is the coloring scheme we used (we only used 3 out of the 5 cables)
      • GND - Green
      • 5V on each joystick- RED
      • VRx of Left Thumbstick - White
      • VRy of Right Thumbstick - Black
    • Hint: Remember the color that you have assigned to each

Step 6: Solder ATTINY 85 Microcontroller to Breadboard

  1. Solder Both ATTINY 85 Chips to a portion of the board.
    • Each ATTINY will be used to control one of the Thumb-stick Joysticks
    • HINT: We placed a white tape to signify that this controller is meant for the Y axis thumb-stick
  2. Assign a piece of wiring that is consistent with where they will end up going in accordance to the car controller and the thumb-sticks (circuit diagram in next slide)

Step 7: Connecting Joystick to Microcontroller

  1. Circuit diagram showing the wiring configuration for the joystick controller and ATTINY 85 Micro-controller
  2. The Left/Right Joystick will go into the X Axis pin of the Microchip and the Up/Down Joystick will be soldered to the Y Axis Joystick
  3. The Digital Out from each of these controllers will then be wired to the Car’s Controller Input

Step 8: Connect Microcontroller to On-Board Microcontroller

  1. Open the Black on-board microcontroller and solder a piece of wire that controls each directions as well as a wire for voltage and ground
    • That will be 5 wires total
  2. Referring to the circuit diagram on the last screen. Connect the Digital Out of both ATTINY’s to the wire soldered to the corresponding pins on the onboard controller using a wire connector
  3. Use Velcro tape to Attach Breadboard to wall of car

Step 9: Set Up the Light Sensor

  1. Connect the KY033 Light Sensor to a Ground and 5V wire by bundling it with those corresponding cables using a wire connector
  2. Connect the “S” line to the micro-controller by bundling that signal line to the X-Axis analog input from joystick

Step 10: Position the Light Sensor

  1. Use a stiff apparatus and Velcro to to position the light sensor directly above the small Rod in the circular centerpiece of the axle
  2. Attach a piece of White/Shiny Tape to the Small Black metal rod in the center axle piece.
  3. Use the code attached to load to the KY033 using Arduino IDE.

Step 11: Set Up a Switch for the Joystick Controller and Stock Remote Controller

  1. Connect the OFF Switch by bundling the 5V wire of the Black Onboard Microcontroller using a wire connector
  2. Connect the ON switch by bundling a piece of wire to the 5V input source of the ATTINY 5V wires using a wire connector

Step 12: Cushion the Joystick Handlebars

  1. Wrap the handlebars and joystick with pieces of pool noodles that are cut to installation size.
    • Use pictures as reference