FPV Robot

This repository contains schematic and software to build 4WD FPV robot/car based on Raspberry Pi and Arduino. The robot is controlled via a web interface using Wi-Fi.

Hardware

The 4WD robot car platform is used as chassis. The Raspberry Pi with camera module is used to run web server and stream video. The Arduino Pro Mini is used to control motors, servos, lighting and read batteries voltage level. Arduino is connected with Raspberry Pi via serial connection (UART).

Schematic in schematic.pdf.

Supplies:

• 4WD Mobile Platform for Arduino Smart Robot Car [https://www.elecrow.com/4wd-mobile-platform-for-arduino-smart-robot-car-p-1531.html]
• Raspberry Pi 3 Model B+
• Raspberry Pi Camera Module
• Micro SD memory card
• Arduino Pro Mini 3.3v ATmega328P
• MX1508 Dual DC Motor Driver Module
• Pan and Tilt Stand [https://www.electromaker.io/shop/product/assemb-mini-pan-tilt-kit-wmicro-servos]
• 2 x SG90 Servo
• LM2596S Step Down DC-DC Converter
• MP1584EN Step Down DC-DC Converter
• AMS1117 5.0V Voltage Regulator (module or single chip)
• AMS1117 3.3V Voltage Regulator (module or single chip)
• 3S 18650 Batteries Holder Case
• 3 x 18650 Li-Ion Batteries
• Switch like SS12D07
• 30K resistor
• 10K resistor
• 3K resistor
• 2N2222A NPN Transistor
• 2 x 10uF tantalum capacitor (if using AMS1117 as single chip)
• 2 x 22uF tantalum capacitor (if using AMS1117 as single chip)
• 5 x 3mm white LEDs
• Wires, screws, PCB protoboards, etc.

Software

• The ard1 directory contains Arduino sketch
• The fpvrobotrpiserver directory contains web server application written in Python/aiohttp to run on Raspberry Pi

Arduino sketch

The Arduino sketch requires servo library.

Web server

To run web server application on Raspberry Pi firstly download and install Raspberry Pi OS to memory card. Then configure Wi-Fi and enable SSH. Determine Raspberry Pi IP address using sudo ip addr. Connect via SSH and install these packages:

sudo apt install git \
                 python3-aiohttp \
                 python3-aiohttp-jinja2 \
                 python3-picamera2 \
                 python3-pip \
                 python3-serial

Then install aioserial:

sudo pip3 install aioserial

Optionally for HTTP basic authentication install aiohttp-basicauth

sudo pip3 install aiohttp_basicauth

Clone this repository:

git clone git@github.com:lostclus/FPVRobot.git

Run application:

cd FPVRobot
python3 -m fpvrobotrpiserver

Then in other device that connected to same local network open web browser and go to http://<IP>:8080

Configuration

Web server application can be configured using environment variables.

Environment variables

Variable	Description	Default value
HOST	Host for HTTP server	0.0.0.0
PORT	Port for HTTP server	8080
ARD1_PORT	Serial port to communicate with Arduino	/dev/serial0
ARD1_BAUDRATE	Boud rate of serial connection	9600
ARD1_TIMEOUT	Timeout of serial connection	0.1
DEFAULT_CAMERA_SIZE	Default camera resolution	640x480
DEFAULT_CAMERA_QUALITY	Default camera quality	2
CAMERA_TRANSFORM	Camera transformation	hflip,vflip
AUTH_USER	User name for authentication
AUTH_PASSWORD	Password for authentication

User Interface

Robot movement, camera movement and lighting control can be via keyboard, mouse or touchscreen.

Keyboard control

Key	Action
W	Move forward
S	Move backward
A	Turn left
D	Turn right
Space	Stop motors
Up arrow	Turn camera up
Down arrow	Turn camera down
Left arrow	Turn camera left
Right arrow	Turn camera right
Home	Center camera
L	Toggle lighting

Top pannel

Icon	Description	Click Action
🎚	Camera settings	Toggle settings view
👌	Session is active	Make session not active
🔒	Session is not active	Make session active
🔋	Normal battery voltage level	Power off Raspberry Pi
🪫	Low battery voltage level	Power off Raspberry Pi