Servo Steering Robot Car for Arduino




About: I am a fan of arduino, and I like to make some of my favorite robots.

This car is based on the arduino platform design, the core is the Atmega - 328 p, which can realize the front wheel steering, rear wheel drive and other functions.

If you just play alone, only need to use the wireless module;If you want to implement other functions, you may need to add other sensors or hardware.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: The Required Parts

When you want to have a controlled by the steering gear to car,You need the following parts:

  • Arduino:arduino Compatible version(blue bird)
  • Motor driver board :PM-R3
  • Power battery :7.4V -18650
  • Remote control part :PS2(of course, you can also use bluetooth control)
  • Dupont line :a small amount of
  • Of course, you will also need the car frame(include motor , servo)

PM - R3 module integrated I/O expansion and motor drive

  1. Dual motor output
  2. Power input
  3. Digital I/O (S V G)
  4. Analog I/O

Step 2: Install the Frame(Drive Part)

First we install the drive part, drive motor is JGA25-370, through a gear reduction drive axle and wheel forward retreat, the motor shaft gear is big, because after the drive shaft and support distance is small, can't install big gear, but overall still slow.

Rear wheel bearings with flange bearings, to prevent the gear sliding down when running, you can also reduce power consumption.

  • motor bracket x1
  • 370 high speed motor x 1
  • Gear A pair
  • 5mm shaft x 1
  • Flange bearing x 2
  • 5mm coupling x 2
  • M3 * 8 mm screw and nut x 5

Step 3: Front Steering Parts

Before turning part adopts the design of the RC, also with most of the accessories, such as the wheel parts;In order to keep the wheels of flexible, both inside and outside the bearing with installation.MG996R metal as power steering, the steering gear with two L shaped bracket should be fixed to the chassis,Servo motor connecting rod when installation, please ensure the steering Angle are already owned by (1.5 ms), the switch to the scope of the convenient adjustment and in the late.

  • M2.5 * 12mm screw and nut x 1
  • M3 * 8mm screw and nut x 4
  • M4 locknut x 2

Step 4:

Will be assembled to part and servo motor is fixed to the turf,Can't tighten the screw fixed to a cup, it will lead to can't turn, is likely to burn out the servo motor and single chip microcomputer;Using the connecting rod connects two front wheels, and connected to the servo motor on the rudder Angle;Servo motor is fixed with the M3 * 8 mm screw and nut, fixed with M2.5 * 8 mm screw to cup, copper column side is 2 M3 * 8 mm screw.

  • M2.5 * 8mm x 5
  • M2.5 * 20mm x 1
  • M3 * 8mm x 10
  • M3 nut x 4
  • Copper pillar x 4

Step 5: Connection Part

Motor driven extension board can be used directly, and the mainboard without other wiring,just need to PS2 receiver and servo motor upon receiving the I/O port expansion board, the power input port in the VCC & GND expansion board, motor output in A + and A -,another motor output in B+ and B-.So, we can control the two dc motors, here we only need one interface.

Servo Pin : I/O 4

PS2 did a transfer board, convenient wiring, reverse connect protection, recommend the following connection here

PS2 Pin :

  • GND : GND
  • VCC : +3.3v or +5v
  • DAT : A0
  • CMD : A1
  • CS : A2
  • CLK : A3

Power input VIN & GND, 3-9 v voltage range.

Step 6: Code

Through the modification of the program to achieve the robot's walking, motor control forward and back, servo control direction; program contains PS2 control, Bluetooth control and follow-line.

The program should be changed to the latest version to match the new PM-R3.

Old code see PS2_old

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    11 Discussions


    6 months ago


    Thanks for the tutorial. I purchased the same exact chassis from, but I am using the Raspberry Pi 3 Model B instead of an Arduino. I am using Pololu motor drivers and regulators, four HC-SR04 ultrasonic sensors for obstacle avoidance, and a 12V NiMH battery for the power supply. The chassis did not come with any instructions or documentation, so I used the diagrams from your tutorial to assemble it. I cannot read Chinese, so I do not how to interpret the motor or servo specifications.

    What is the nominal voltage, operating voltage, and stall current of the JGA25-370 motor?
    What is the nominal voltage, operating voltage, and stall current of the servo?
    How did you supply power to the Arduino and servo? Did you use voltage regulators?
    How long does your battery last before you need to recharge it?

    Please let me know if there is an email address I can contact you with.

    2 replies

    Reply 6 months ago

    I use 2S, 2200mah, I can use it for about an hour.This is my mail


    Reply 6 months ago

    Cool, Raspberry Pi is very powerful, I am looking forward to your tutorial; GA25-370 motor is 6-12V voltage, locked current 3A; servo is 4.8-7.2V voltage, I did not use another power supply to power servo I used the 5v on the board. If you need to supply additional servo power, remember to share the ground.


    6 months ago

    Great project :)
    Please make a tutorial like this but with bluetooth module

    1 reply

    Reply 6 months ago

    Bluetooth I use BC04, the serial port of the motherboard can be used, the wiring is very simple, other line sequences do not need to be changed, the mobile APP and code can be downloaded above.


    9 months ago

    in arduino IDE (i use 1.6.4), i can't compile the sketch in UNO, it's giving me error message

    collect2exe: error: id returned 5 exit status,

    when i compile the sketch in MEGA, it's done, no error appear,
    any suggestion? sorry for my language

    thanks, arie

    1 reply

    Reply 6 months ago

    Sorry, I haven't seen your message for a long time. I don't know if you have solved this problem. You can try to test it with other code.


    2 years ago

    what is the source for the car frame, motor and steering assembly?

    1 reply

    Reply 2 years ago

    Their own design frame and motor bracket, turned to cup is 1:16 model cars