This tutorial shows how to build a smartphone-controlled FPV (First-Person View) car using Grablo's visual programming blocks. Stream live video to your phone and control the car with an on-screen joystick—drive your robot from anywhere, even outdoors using mobile hotspot!

What You'll Build

A smartphone-controlled FPV car with:

Real-time camera streaming to your smartphone
Intuitive joystick control via mobile dashboard
Differential drive steering using wheel speed differences
Outdoor capability using mobile hotspot

Supplies

Required Components

Raspberry Pi (any model with camera support)
Raspberry Pi Camera Module or USB webcam
L298N motor driver
2x DC motors with wheels
Robot chassis (Arduino-compatible car chassis works great)
Power bank for Raspberry Pi (5V/2A minimum)
2x 18650 batteries (in series) for motors
Jumper wires

Wiring: Refer to attached wiring diagram

⚠️ Critical Notes:

Keep Raspberry Pi and motor power supplies separate
Connect common ground between Raspberry Pi and L298N

Step 1: Quick Start

Download and install Grablo software on your Raspberry Pi
Wire components according to circuit diagram
Get this project
Open Grablo app on your smartphone browser
Enter Raspberry Pi's IP address and run

To build it yourself, continue to Step 2.

Step 2: Create Dashboard

Create Project & Dashboard

Go to https://app.grablo.co
Click "Create Project"
Name your project
Create a new dashboard

Add Widgets

Camera Widget: Create a new camera with default settings.
Joystick Widget: Create X and Y variables, assign to joystick. Keep min/max at -100/100.

💡 Tip: Adjust mobile dashboard layout for smartphone control. You can fine-tune it later on your phone.

Step 3: Create Logic

Control 1 - Start Camera

Start the camera once when the project begins.

Condition (Once): Run once at startup
Action (AI Camera): Start camera, leave AI Analysis empty

Control 2 - Motor Control

Control wheel speeds based on joystick input.

Condition (Always): Run continuously
Action 1 (I/O Device Control): Set left motor speed
Action 2 (I/O Device Control): Set right motor speed

Motor Speed Formula

For differential drive steering without a servo:

Left wheel: Y + (X × 0.4)
Right wheel: Y - (X × 0.4)

The 0.4 ratio prevents overly sensitive turning. Adjust to your preference.

Step 4: Connect to Wi-Fi

With Monitor/Keyboard: Click the Wi-Fi icon in the top right corner.

Without Monitor (SSH):

Connect via SSH using Putty
Run sudo raspi-config
Select System Options → Wireless LAN
Enter Wi-Fi name and password

For Outdoor Use (No Wi-Fi):

Turn on your smartphone's hotspot
Connect Raspberry Pi to hotspot
Find Raspberry Pi's IP in hotspot settings → Connected devices
Use that IP address to connect

Step 5: Launch Your Project

That's it—you're done!

Launch Your Project

Open Grablo app on your smartphone browser
Select your project
Click Connect and enter Raspberry Pi's IP address
Hit RUN and drive!

Expected Results

When you run your project:

Camera feed appears in real-time on your phone
Push joystick forward: car moves forward
Push joystick backward: car reverses
Steer left/right: car turns using differential drive
Release joystick: car stops
Works anywhere with Wi-Fi or mobile hotspot

Step 6: Video Tutorial

Watch the complete build process in action!

Step 7: Expand Your Project

Add more functionality:

Distance sensor for collision avoidance
Voice control (STT) and voice output (TTS)
LED effects

Troubleshooting

No camera feed:

Check camera connection and settings
Try different camera index for USB camera

Car not responding:

Verify GPIO wiring and battery charge
Check Wi-Fi/hotspot connection

Steering feels wrong:

Adjust X-axis ratio (0.3~0.5)
Swap motor direction (True/False)

Resources

Introduction: Smartphone-Controlled FPV Car (No Code)