Wireless Remote Control Robot Car With NRF24L01

As kids we all loved toys and as a boy I loved remote controlled toys especially. My dad would get me a new toy every time he travelled and they were mostly remote controlled cars or trucks.

Playing with these toys in a way got me interested in tech. When I started learning Arduino and C++, I saw this as an opportunity to build my own toys and make some advancements I couldn't get from the said toys.

Therefore, in this project I will be walking you through how to make your own simple remote controlled robot car.

• Robot Car Chassis Kit (x1)

Amazon.com: The perseids DIY Robot Smart Car Chassis Kit with Speed Encoder, 4 Wheels and Battery Box (4 Wheels) (4TPP) : Toys & Games

• Arduino Uno R3 (x2)

Amazon.com: Arduino UNO REV3 [A000066] : Electronics

• NRF24L01 Transceiver Module (x2)

Amazon.com: HiLetgo 4pcs NRF24L01+ Wireless Transceiver Module2.4G Wireless Transceiver Module : Electronics

OR

Amazon.com: HiLetgo 2pcs NRF24L01+PA+LNA Wireless Transceiver RF Transceiver Module with SMA Antenna 2.4G 1100m : Electronics

• Joystick Module (x1)

Amazon.com: HiLetgo Game Joystick Sensor Game Controller Sensor JoyStick Breakout Module for Arduino PS2 Raspberry Pi : Video Games

• L298n Motor Driver (x1)

Amazon.com: HiLetgo 4pcs L298N Motor Driver Controller Board Module Stepper Motor DC Dual H-Bridge for Arduino Smart Car Power UNO MEGA R3 Mega2560 : Industrial & Scientific

• Jumper Wires (Male-to-Female and Male-to-Male)

Amazon.com: EDGELEC 120pcs Breadboard Jumper Wires 10cm 15cm 20cm 30cm 40cm 50cm 100cm Wire Length Optional Dupont Cable Assorted Kit Male to Female Male to Male Female to Female Multicolored Ribbon Cables : Electronics

• Hot Glue Gun

Amazon.com: KEMAISI Hot Glue Gun, 100W Full Size Hot Glue Gun kit with 30pcs Premium Hot Glue Sticks, Temperature Adjustable Heavy Duty Hot Glue Gun, Best Large Glue Gun for Crafts : Arts, Crafts & Sewing

After putting together the chassis and attaching the wheels, decide which side of your chassis will be the front for the forward direction.

Connect each motor to a battery (3.7 - 4.2 volts) and note which polarity (+ve and -ve) causes each one to rotate in the forward direction.

Connect the left side motors in parallel and right side motors in parallel (i.e +ve wires together and -ve wires together), each side independent of the other.

Using the hot glue gun mount the motor driver on the chassis with its back (black heat sink) facing the back of the vehicle / front of the vehicle facing away from you or (i.e Out1 and Out2 on the right side and Out3 and Out4 on the left side) and glue it down.

Note: The blue arrow in the picture above indicates the forward direction of the car and how the motor driver should be placed.

Keep in mind that this orientation will make it easier for us to program the car later.

With the front of the vehicle facing the same direction as you;

For the right side motors, (assuming they are already connected in parallel as specified in step1) connect the +ve to Out1 and -ve to Out2.

For the leftside motors, connect the +ve to Out3 and -ve to Out4.

Using the male-to-female jumper cables, connect the motor driver IN pins and power pins to the Arduino as follows;

Motor Driver ---------> Arduino

IN1 ---------> pin 2

IN2 ---------> pin 3

IN3 ---------> pin 4

IN4 ---------> pin 5

5 V (Volts) ---------> Vin

GND (Ground) --------> GND

Connect jumper wires to the GND and 12V of the Motor driver (to supply power to the driver from a 7 -12 Volts battery). So that the Motor driver and the Arduino share a common GND.

Also, short-circuit the ENA (Enable A) and ENB (Enable B) pins on the motor driver.

Remember to hold the Arduino down to the chassis using some hot glue.

Basically, the NRF can act as both a receiver and a transmitter although not simultaneously but one at a time.

This particular NRF24L01 will be serving as the receiver, receiving instructions from the remote controller.

Using the picture above as a guide, connect the transceiver to the Arduino keeping everything the same except CE/SS and CSN.

Connecting the NRF pins starting from the left, bottom row first.

NRF24L01 ---------> Arduino

GND(boxed pin)---------> GND

CE / SS ---------> pin 7

SCK ---------> pin 13

MISO ---------> pin 12

Top row next;

Power (3.3v) ---------> 3.3V

CSN ----------> pin 8

MOSI ---------> pin11

Firstly, connect the Joystick module to the Arduino (second Arduino);

Joystick ---------> Arduino

VRx ---------> analog pin A1

VRy ---------> analog pin A2

GND ---------> GND

+5V ---------> 5V

Then connect the second NRF24L01 to the aforementioned Arduino following the steps stated in step 5.

Connect a 9V battery to the Arduino to power the remote controller.

The code for both the car (receiver) and the controller (transmitter) can be found on my Github.

Hooray!!! everything works.

This car was made purely for educational purposes. You can cut out some cardboard and make yours a lot prettier.