Revision 1.1 RC Drift Gyro Controller Hardware Architecture and Design
Revision History
| Revision | Date | Description |
| 1.1 | 2026-07-18 | Expanded hardware architecture |
1 Introduction
The JG-01 controller is a dedicated embedded control unit designed for 1/10 scale RC drift vehicles. The objective of the hardware platform is to provide deterministic real-time steering stabilization while remaining compact, reliable and easy to manufacture.
The controller integrates an ESP32-S3 processor, a Murata SCH16T industrial inertial sensor, Bluetooth Low Energy connectivity, USB programming, receiver interfaces and dual PWM servo outputs on a single PCB. The hardware has been designed together with the firmware, allowing deterministic sampling of the gyroscope and a fixed-rate control loop.
2 Hardware Overview
The PCB is divided into functional blocks consisting of the power supply, ESP32-S3 processing subsystem, Murata IMU, USB interface, SPI bus, receiver interfaces and PWM outputs. This modular architecture simplifies both firmware development and future hardware revisions. Time-critical peripherals are isolated from configuration and communication functions, improving maintainability.
3 Power Supply
The controller receives power through a USB Type-C connector during development and bench testing. USB provides a stable 5 V input which is converted to a regulated 3.3 V rail by an AMS1117 linear regulator.
All onboard electronics, including the ESP32-S3 and Murata SCH16T sensor, operate from the common 3.3 V supply. Using a single logic voltage eliminates the need for level translators and simplifies PCB routing.
Local decoupling capacitors are placed close to every major integrated circuit. These capacitors reduce supply impedance during transient current peaks generated by wireless communication and improve measurement stability of the inertial sensor.
The steering servos are intentionally not powered from the PCB. They receive power directly from the vehicle electronics, preventing high servo current peaks from disturbing the controller power rail.
4 USB Interface
The USB Type-C connector serves three purposes: supplying power during development, downloading firmware to the ESP32-S3 and providing a convenient maintenance interface.
The ESP32-S3 contains native USB functionality, removing the need for an external USB-to-UART converter. This reduces component count while improving programming reliability.
ESD protection devices are included on the USB data lines to improve robustness against electrostatic discharge during repeated cable insertion and removal.
5 SPI Bus Architecture
SPI is the primary high-speed communication bus of the controller. The Murata SCH16T-K10 inertial sensor is connected to this bus because deterministic timing and high bandwidth are essential for the steering algorithm.
The same SPI bus is also routed to an external expansion connector intended for SD card logging and future peripherals. Each SPI device uses an independent chip-select signal, allowing multiple peripherals to share the bus safely.
Within the firmware, access to the SPI bus is prioritised so that real-time sensor acquisition always has precedence over lower-priority background tasks such as data logging. This approach combines hardware simplicity with deterministic real-time performance.
6 PWM and Receiver Interfaces
The hardware provides dedicated PWM outputs for steering servo control. Both single-servo and dual-servo steering configurations are supported by the PCB layout and firmware.
Receiver connectors accept steering and auxiliary control signals from the RC receiver. The firmware measures incoming pulse widths with precise timing before converting them into normalized steering commands.
The controller operates inline between the receiver and steering servo. Incoming driver commands are combined with gyroscope feedback to produce corrected PWM outputs while maintaining minimal latency.
7 Design Summary
The hardware architecture has been designed around deterministic real-time control rather than maximum peripheral count. Fast SPI communication, dedicated PWM outputs, protected USB connectivity and a clean power architecture provide a solid foundation for the embedded firmware.
The modular design also leaves room for future expansion through the external SPI connector while maintaining compatibility with the existing firmware architecture.