Introduction: Arduino Lego Technic Racer 42065 + PS2 + Wireless 2.4GHz NRF24L01

By krakiewicz.pl
About: Spread Your ideas...

Code:
https://github.com/oscdeveloper/arduinoLegoTechnicRacer

More photos here

Things used in this project (bought on AliExpress):

  • 1x Arduino Nano for TX
  • 1x Arduino Pro Mini for RX
  • 1x DRV8833 H-Bridge Motor Driver
  • 2x PCB board 5x7cm
  • Some wires 0.2mm thickness
  • Paper box for TX
  • 1x PS2 Pad (not original) with PS2 plug (not USB)
  • 1x orange LEDfor TX status
  • 2x power switch
  • Hot melt glue gun
  • 3x resistors 1k for transistors base (LEDs)
  • 1x resistor 2k red taillights LEDs
  • 1x resistor 200 white side beams LEDs
  • 1x resistor 2k white front beams LEDs
  • 2x transistors for LEDs current as switch on/off
  • 1x buzzer for Lego Vehicle horn sound
  • 1x LiPo 7,4V 1300mAh for Lego Vehicle Racer. It should be more, max 10V (DRV ratings)
  • 1x Lipo 7,4V 700mAh 2S for TX
  • 2x Lego Motor size M
  • 1x Lego Technic Racer no. 42065


Notes:
NRF library: http://tmrh20.github.io/RF24/
PS2 library: https://github.com/madsci1016/Arduino-PS2X/zipball/5d2be701af64d826d268301d83119a6d2ad04f15

Step 1: Transmitter - PCB for PlayStation2 Controller

  1. First we should find some small box for all elements inside of TX.
  2. Take PCB 5x7cm.
  3. Prepare PCB and pin headers for Arduino Nano or Pro Mini.
    I move it to the end of PCB because of space between Arduino and PS2 connector inside of a box. Arduino is flipped upside down.

Step 2: Connections PS2 Pad / Arduino

  1. Buy some Chinese PS2 Controller from ex. AliExpress.
  2. All connections You can find here: http://www.techmonkeybusiness.com/using-a-playstation-2-controller-with-your-arduino-project.html
  3. I choose a cheaper solution and wired it straight from plug to Arduino.
    I can recommend You to stick some notes to wires about what is what.
  4. Put glue on the wires and open pieces of solders just to isolate it and make connections stronger due to often taking out a battery to charge.

Step 3: Transmitter - Final Look

  1. You see orange LED applied next to power switch.
    It's for transmitter status.

    Status:
    Blinking - TX is powered on, but doesn't have established connection with RX (Receiver in Lego Technic NRF24L01 module)
    Constant - TX is powered on and has a connection with RX
  2. At the top of a box is placed NRF24L01 module with power adapter under the hood :)

    https://www.google.pl/search?q=NRF24L01++adapter

  3. Black rubber band is to hold it tight in one piece.

Step 4: Battery Basket

  1. Try to make a basket from Lego placed in chassis frame at the bottom.

Step 5: Lego Receiver - Wires, LEDs & PCB

  1. I placed PCB at the end of a vechicle. It's the best place for it. Thanks to this it looks like a real working engine :)
  2. All wires between LEDs and PCB are going through chassis under the hood.

Elements used for LEDs:

  • 2x transistors
  • Resistor 1k for base in transistors
  • Resistor 2k for front LEDs
  • Resistor 200 for side LEDs
  • Resistor 2k for taillights LEDs