Robot aio esp32 manuel solder 8 layer

Robot AIO ESP32 Controller

Compact all-in-one ESP32 controller for RC cars, mobile robots and small combat robots.

This PCB was designed to replace the usual collection of an ESP32 development board, multiple motor-driver modules, voltage regulators and large amounts of wiring with a single compact controller.

The board integrates an ESP32-WROOM-32UE, four independent brushed DC motor drivers, onboard power regulation, battery-voltage monitoring, programming/debug connections and additional GPIO into a 50 × 46.2 mm PCB.

The controller has been manufactured, hand-assembled and fully tested, and the finished board is operational.

Status: Hardware tested and working PCB: 8-layer, 50 × 46.2 mm Controller: ESP32-WROOM-32UE Motor channels: 4 × bidirectional brushed DC Battery: 2S–4S Application: RC cars, mobile robots and small combat robots

Why I Built This

Small competition robots often end up containing several separate modules:

• ESP32/Arduino development board
• multiple H-bridge motor drivers
• voltage regulator
• battery-monitoring circuit
• programming hardware
• connectors
• large amounts of point-to-point wiring

This works, but it takes space, adds failure points and makes the electrical system much harder to package cleanly inside a small robot.

The goal of Robot AIO was to integrate the essential electronics of a small mobile robot onto one board.

It was originally designed with Robot Wars / combat robotics and RC-car projects in mind, where compact packaging, fast assembly and simple motor control are particularly useful.

Hardware Images

The final PCB shown above has been assembled and tested successfully. The repository also includes the design views below.

PCB Layout

Schematic

A demonstration video is not currently included in this repository. To add one later, place it in the Media directory and link it here.

Features

4 Independent Brushed Motor Channels

The board contains four DRV8231 H-bridge motor-driver stages.

Each channel supports:

• forward rotation
• reverse rotation
• PWM speed control
• active braking
• independent ESP32 control

This makes the board suitable for configurations such as:

• 2-wheel differential drive
• 4-wheel differential drive
• skid-steer robots
• mecanum/omnidirectional platforms
• RC vehicles
• small combat robots
• other multi-motor robotic platforms

Each motor has its own 2-pin screw terminal.

ESP32 Controller

The main processor is an:

ESP32-WROOM-32UE

This provides:

• dual-core ESP32 processing
• Wi-Fi
• Bluetooth
• hardware PWM
• ADC
• UART
• SPI
• I²C
• additional GPIO for sensors and peripherals

The 32UE variant also allows an external antenna to be used, which is useful when the controller is mounted inside a robot with significant metal structure around it.

Possible control methods therefore include:

• Bluetooth gamepads
• phone control
• custom wireless controllers
• Wi-Fi control
• conventional RC receiver interfaces
• autonomous control

The exact control system is implemented in firmware rather than being locked into the PCB.

Hardware Architecture

                    2S–4S Battery
                         │
             ┌───────────┴───────────┐
             │                       │
             ▼                       ▼
       Motor Supply            TPS56528 Buck
             │                       │
             │                      3.3 V
             │                       │
     ┌───────┼────────┐              ▼
     │       │        │          ESP32-WROOM
     │       │        │              │
     ▼       ▼        ▼              │
   DRV1    DRV2     DRV3    DRV4    │
     │       │        │       │      │
     ▼       ▼        ▼       ▼      │
  Motor 1 Motor 2  Motor 3 Motor 4   │
                                    │
                         ┌──────────┴─────────┐
                         │                    │
                    Battery ADC         Expansion GPIO

The motor drivers operate directly from the battery rail while the ESP32 and logic circuitry are supplied by the regulated 3.3 V rail.

Motor GPIO Mapping

The four motor drivers are controlled directly by ESP32 GPIO.

Each channel can therefore be independently controlled using the ESP32 PWM peripherals.

For differential-drive robots, for example:

Left Motors  → Motor 1 + Motor 2
Right Motors → Motor 3 + Motor 4

The assignment can of course be changed entirely in firmware.

Motor Outputs

Each motor channel uses a DRV8231 integrated H-bridge.

The DRV8231 includes:

• integrated N-channel MOSFET H-bridge
• PWM control
• over-current protection
• thermal protection
• under-voltage lockout
• current regulation capability

The IC is rated for up to 3.7 A peak output current.

Important: 3.7 A is the motor-driver IC's peak rating, not a guaranteed continuous-current rating for the complete PCB. Practical continuous current depends on motor load, PCB temperature, cooling, battery voltage and operating conditions.

Always check the stall current of the motor rather than only its no-load/running current.

Motor Noise Suppression

Brushed motors can generate significant electrical noise from commutation.

Each motor output therefore includes an RC suppression network consisting of approximately:

47 Ω + 100 nF

across the motor output.

This helps suppress high-frequency switching and brush noise before it propagates through the rest of the robot electronics.

Additional suppression directly across the motor terminals may still be useful for particularly noisy motors.

Power System

Battery Input

The PCB was designed for:

2S–4S battery systems

Typical LiPo voltage range:

Large solder pads are provided for the main:

VIN
GND

connections.

This avoids passing the combined robot current through a small PCB connector.

3.3 V Regulator

The logic power supply is based around a TPS56528 synchronous buck regulator.

It converts the battery voltage directly to approximately:

3.3 V

for the ESP32 and logic circuitry.

The regulator allows the controller to operate directly from the robot battery without requiring a separate external buck converter.

Battery Voltage Monitoring

Battery voltage is measured directly by the ESP32 through an onboard resistor divider.

The divider uses approximately:

300 kΩ
56 kΩ

with filtering before the ADC input.

The approximate relationship is:

Vbattery ≈ Vadc × 6.36

For example:

ADC = 2.00 V
Battery ≈ 12.7 V

This allows firmware to implement features such as:

• live battery telemetry
• low-voltage warnings
• reduced-power mode
• automatic shutdown behaviour
• battery percentage estimation

The battery-monitor ADC input is connected internally to the ESP32.

Because the ESP32 ADC is not a precision measurement device, calibration against a multimeter is recommended when accurate voltage readings are required.

Expansion Header

A 14-pin 2.00 mm expansion header exposes unused ESP32 connections.

This makes it possible to add peripherals without modifying the controller PCB.

Examples include:

• IMUs
• encoders
• distance sensors
• servos
• limit switches
• LEDs
• current sensors
• RC receivers
• displays
• SPI devices
• I²C devices

Programming Interface

A dedicated programming/debug header provides:

EN
3.3 V
UART TX
GND
UART RX
GPIO 0

This allows the ESP32 to be programmed without permanently adding a USB-to-UART converter to the robot.

Keeping the USB interface off the main board saves both PCB space and components in the finished robot.

LEDs

The PCB includes two LED functions.

Power LED

One LED is connected to the 3.3 V supply and provides a visual indication that the logic rail is powered.

Programmable LED

A second LED is controlled by:

GPIO 2

It can be used for:

• boot indication
• connection status
• controller pairing
• low-battery warning
• fault indication
• debugging

PCB

The controller uses an 8-layer PCB.

Dimensions:

50.0 mm × 46.2 mm

PCB thickness:

1.6 mm

The board includes multiple mounting holes and large ground/power areas to make mechanical installation into a robot easier.

The design was also intentionally created around components that could be assembled manually, allowing prototypes to be built without requiring professional PCBA.

Example Applications

RC Car

A basic RC vehicle can use:

Gamepad / Phone
       │
   Bluetooth
       │
       ▼
     ESP32
     ┌──┴──┐
     ▼     ▼
 Left    Right
Motor    Motor

No external motor-driver module or microcontroller board is required.

Four-Wheel Drive Robot

All four channels can be used independently:

Motor 1 ─ Front Left
Motor 2 ─ Rear Left
Motor 3 ─ Front Right
Motor 4 ─ Rear Right

This is particularly useful for compact skid-steer robots.

Combat Robot

For a small combat robot, the board can combine:

• wireless control
• drive-motor control
• battery monitoring
• status indication
• sensor interfaces

into a single PCB.

High-current weapon motors should normally use a separate appropriately rated ESC or motor controller.

Design Goals

The project was built around several priorities:

Compact

Replace several separate modules with one board.

Simple Wiring

Battery, motors and peripherals connect directly to the controller.

Flexible

The ESP32 allows the same PCB to be used for many different robot architectures.

Repairable

The first prototypes were designed with manual assembly and debugging in mind.

Competition Friendly

The controller is intended for robots where space, weight, reliability and fast repair are important.

Tested Hardware

The manufactured prototype has been assembled and tested successfully.

Verified functionality includes the core controller hardware, power system and motor-control architecture.

See the assembled working PCB, PCB layout, and schematic included in this repository.

This repository contains the design used to manufacture the working prototype.

KiCad Design Files

The PCB was designed using KiCad 9.

Main project files include:

robot aio esp32 manuel solder 8 layer.kicad_pro
robot aio esp32 manuel solder 8 layer.kicad_sch
robot aio esp32 manuel solder 8 layer.kicad_pcb

The repository therefore contains the editable schematic and PCB rather than only manufacturing outputs.

Main Components

Repository Structure

The repository is organised as follows:

ESP32-Robot-AIO-Controller/
│
├── README.md
│
├── Firmware/
│   └── phone_controlled_2servo.ino
│
├── Hardware/
│   └── robot aio esp32/
│       ├── fabrication-toolkit-options.json
│       ├── robot aio esp32 manuel solder 8 layer.kicad_pcb
│       ├── robot aio esp32 manuel solder 8 layer.kicad_prl
│       ├── robot aio esp32 manuel solder 8 layer.kicad_pro
│       └── robot aio esp32 manuel solder 8 layer.kicad_sch
│
└── Media/
    ├── PCB-Image.png
    ├── PCB-Layout.png
    └── Schematic.png

Safety / Important Notes

This is an experimental robotics controller rather than a certified commercial motor controller.

When reproducing or modifying the design:

• verify battery polarity before applying power
• use an appropriately rated external fuse
• use a suitable emergency power-disconnect system for competition robots
• check motor stall current before connecting a motor
• provide adequate cooling for sustained high-current operation
• test the robot with the drive wheels off the ground before full-power operation
• implement a communication-loss failsafe in firmware
• follow the safety requirements of the relevant robotics competition

For combat robots in particular, the controller should form only one part of the complete electrical safety system.

Project Status

Working hardware.

The first manufactured controller has been assembled and tested, and the PCB is functional.

Future development can include:

• example ESP32 firmware
• Bluetooth gamepad support
• RC receiver support
• configurable failsafe logic
• battery telemetry
• closed-loop wheel control using encoders
• additional robot-specific expansion modules

About

Robot AIO was developed as a compact general-purpose electronics platform for my robotics projects, particularly RC vehicles and combat robotics.

The main idea was simple:

One PCB for the controller, power supply, motor drivers and robot I/O — instead of a box full of development boards and modules.