Researched by Riley Hart · based on ELEGOO Smart Robot Car V4 build guide and docs · we may earn a commission
The ELEGOO Smart Robot Car V4.0 is a four wheel camera car you drive from your phone. This guide breaks the build into small steps, each with its own drawing, the exact screws and the mistake most people make on that step.
Plan for 2 to 3 hours. Build the motors, add the line sensor, mount the boards and battery, build the camera and eye tower, wire it up, close the frame and add the wheels. No soldering and no coding.
Same 29 steps on your phone, one at a time. Tick what you should see, and if something looks off, the AI coach checks a photo of your build.
Open the box on a big table. Keep each small bag closed for now. Every bag has a label like FOR MOTOR or FOR CAMERA, and each step tells you which bag to open.
Tip: Start charging the battery box now with the USB cable. It needs about 2 hours.
Check: Bags laid out, still closed.
Common mistake: Pouring every bag into one pile. The screws look alike and are hard to sort later.
The two black plates have a thin protective film on each side. Peel it all off before you build.
Check: Both plates are shiny black, no film left.
Common mistake: Leaving the film on. It traps screws and looks cloudy later.
Open the bag FOR MOTOR. Put a small aluminium block against a motor and push two M3x30 screws through the motor and the block. Add an M3 nut on each. Do all four motors.
Check: 4 motors, each with a silver block.
Common mistake: Using short screws. These are the long M3x30 ones.
Put the bottom plate flat. Fix each motor's block to a corner of the plate with two M3x10 screws from below. Point the motor shafts outward and the wires toward the middle.
Check: 4 motors under the plate corners. All shafts point outward.
Common mistake: Pointing a shaft inward. The wheel will not fit.
Open the bag FOR UNO, LINE TRACKING. Put four white spacer pillars between the plate and the black line tracking board, under the front of the bottom plate. Fix with four M3x14 screws and four M3 nuts. The three sensors face the floor.
Check: Sensor board under the front, sensors facing down.
Common mistake: Mounting it on top of the plate. It has to see the floor.
Open the bag FOR CELL BOX, TIRES, GY-521. Fix the small blue GY-521 sensor onto the expansion board with the M3x11 copper pillar and two M3x5 flat head screws.
Check: Small blue board standing on a gold pillar.
Common mistake: Overtightening. The small board cracks easily.
Fix the UNO board on the top plate with three white spacer pillars, three M3x14 screws and three M3 nuts.
Check: UNO board flat on its spacers.
Common mistake: Skipping the white spacers. Metal parts under the board can cause a short.
Line up every pin of the expansion board with the UNO sockets and press it straight down.
Tip: Look along the side before pressing.
Check: No pins showing outside the sockets.
Common mistake: Pressing at an angle. One bent pin stops the car working.
Fix the black battery box on the top plate behind the boards with two M3x12 screws and two M3 nuts.
Check: Battery box held firm at the back.
Common mistake: Putting the box over the board. Its power switch must stay easy to reach.
Open the bag FOR CAMERA. Screw two M2x6 copper pillars to the black camera bracket with M2x4 screws, then fix the camera board on the pillars with two more M2x4 screws. Plug in one 4 wire cable.
Check: Camera board on the bracket, lens facing out. 4 wire cable plugged in.
Common mistake: Mounting the camera upside down. The lens goes at the top.
Open the bag FOR ULTRASONIC. Put the blue servo with its white holder through the small black plate. Fix it with two M2x10 screws and two M2 nuts.
Check: Servo held under the holder plate.
Common mistake: Twisting the servo arm by hand. It sets the eyes straight later.
Fix the blue ultrasonic sensor (the part with two round eyes) to the front of the white holder with two M1.6x8 screws and two M1.6 nuts.
Check: Two eyes facing forward.
Common mistake: Using the long M1.6x16 screws. Those are for the next step.
Fix the camera bracket to the back of the white holder with two M2x6 copper pillars, two M1.6x16 screws and two M1.6 nuts.
Check: Camera stands above the eyes, both face forward.
Common mistake: Facing the camera backward. Lens and eyes must look the same way.
Fix the whole tower to the front of the top plate with three M3x10 screws and three M3 nuts.
Check: Tower stands straight at the front.
Common mistake: Mounting it at the back. The eyes go over the narrow front.
Plug the servo's 3 wire plug into the port marked Servo1 on the expansion board. Brown wire to GND.
Check: Servo plug in Servo1. Brown wire on GND.
Common mistake: Plugging it in backwards. Check the wire colors match the pin labels.
Connect the ultrasonic sensor to its port with a 4 wire cable, then plug the camera cable into the camera port.
Check: Both 4 wire cables clicked in.
Common mistake: Swapping the two plugs. Check the port labels on the board.
Open the bag FOR ACRYLIC BASEPLATE. Screw six tall M3x40 gold pillars onto the bottom plate with six M3x10 screws from below.
Check: Six posts standing straight.
Common mistake: Mixing up pillar sizes. These are the tallest gold ones.
Plug each motor into its port: left front M1, right front M2, right rear M3, left rear M4.
Tip: Front means the end with the eyes.
Check: All 4 motor plugs in the right ports.
Common mistake: Plugging a motor into the wrong port. The car spins or drives backward.
Connect the line tracking board under the car to its port with the 5 wire cable.
Check: 5 wire cable clicked in at both ends.
Common mistake: Letting the cable hang low. It will drag on the floor.
Place the top plate on the six posts and fix it with six M3x10 screws.
Check: Top plate firm on all six posts. No wire pinched between plates.
Common mistake: Trapping a wire between the posts and the plate.
Push a wheel onto each motor shaft, then fix it with an M2x25 self tapping screw through the center.
Check: 4 wheels on, each spins freely.
Common mistake: Forcing the wheel at an angle. Line up the flat side of the shaft first.
Compare your car with the finished car. Every cable plugged in, nothing touching the wheels.
Check: No loose cables. Wheels spin without touching wires.
Common mistake: Skipping this check. A loose plug is the top reason a part does not work.
Slide the power switch on the battery box to ON. The status light on the board comes on.
Check: Status light is on.
Common mistake: Battery not charged. A red light means it is low.
Pull the plastic tab out of the remote. Use the arrows to drive. Press 1 for line following, 2 for obstacle avoiding, 3 for follow me.
Check: The car drives with the arrows.
Common mistake: Leaving the plastic tab in the remote. Nothing happens.
On your phone, install the EleRobot app from the App Store or Google Play.
Check: EleRobot app installed.
Common mistake: Installing an old Elegoo app. Look for EleRobot.
On the expansion board, slide the small switch from upload to cam.
Check: Switch is on cam.
Common mistake: Leaving it on upload. The app cannot connect.
In your phone's Wi-Fi settings, join the network named ELEGOO followed by numbers. When the phone says No internet, stay connected.
Check: Phone shows ELEGOO Wi-Fi connected.
Common mistake: Letting the phone switch back to home Wi-Fi.
Open EleRobot, pick Smart Robot Car, tap Remote Control and OK. Use the round joystick, then try FPV mode to drive using the camera view.
Check: The car moves with the joystick. You can see the camera view.
Common mistake: Pushing the joystick all the way. Start with small pushes.
In the app, try Obstacle Avoidance: put it on the floor and watch it turn away from walls. Then try Line Tracking on a black tape line.
Tip: If it misses the line, use keys 4, 5 and 6 on the remote to tune the sensor.
Check: It turns away from walls on its own.
Common mistake: Testing line tracking on a dark floor. Use black tape on a light floor.
Same 29 steps on your phone, one at a time. Tick what you should see, and if something looks off, the AI coach checks a photo of your build.
Make a loop with black tape on a light floor and time one lap in line tracking mode.
Drive into another room using only the camera view.
Press 3 and walk slowly. The car follows your hand.
Drawings by robotsforthat. ELEGOO Smart Robot Car V4 is a trademark of ELEGOO. We are not affiliated with ELEGOO.