2 layers36.7 × 75.2 mm Shifter, the printed circuit board in 3D

Shifter

Rally Shifter Pro is a fully open DIY sim-racing sequential shifter based on a mechanical design sourced from GrabCAD. It integrates a custom ESP32-S3 firmware exposing a native USB HID Gamepad, analog Hall effect sensing (SS49E), and a polished Python desktop application for real-time telemetry, calibration, and configuration.

Open in PCBKit

Size: 36.7 × 75.2 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 3
Nets: 39
Pads: 49
Tracks, vias: 40, 0
Pours: 1
Routed: Yes
KiCad: KiCad 10.0 (file 20260206)
Created: 9 Apr 2026
Updated: 12 May 2026

Overview

Shifter is an open-source printed circuit board by LMHDPRO, from the LMHDPRO/open-sequential-shifter repository on GitHub. It is a 2-layer board of 36.7 × 75.2 mm with 3 parts on 39 nets, routed with 40 tracks and 0 vias.

It is built around the ESP32-S3-DEVKITC-1-N8. Its parts include 2 connectors and 1 IC. It belongs with the ESP32 boards of this library.

Main components

ESP32-S3-DEVKITC-1-N8
-- WiFi Modules ROHSEspressif SystemsWiFi Modules

README

README.md

text

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Open DIY Sequential Shifter — ESP32-S3 · Hall Sensor · USB HID

Open-source, plug-and-play USB sequential shifter with analog Hall sensing and pro-grade desktop calibration software.

Compact mechanical design (80×80×5 mm), CNC-machined aluminum body, and a clean Python UI — assembled in minutes, no drivers required.

Overview

Mechanical design source: GrabCAD — Mini Sequential Shifter and Handbrake (80×80×5 mm)
All credit to the original mechanical designer.

Features

USB HID Gamepad — plug & play, no drivers needed on Windows, Linux, or macOS
Analog Hall sensor (SS49E) — true continuous sensing, no mechanical wear
Signal processing pipeline — moving average filter → normalization → dead zone → hysteresis
On-device calibration — 3-step wizard (min / center / max)
Persistent configuration — settings saved to ESP32 NVS (survives power loss)
Serial CDC protocol — bidirectional JSON config, live STATUS, PING/PONG
Desktop companion app — live telemetry, deadzone tuning, calibration wizard (PySide6)
Compact form factor — 80×80×5 mm main body
All-metal construction — CNC aluminum 6061, bronze bushings, PLA/PETG printed parts

System Architecture

text

[ Mechanical Assembly — CNC Al 6061 + Printed Parts ]
                        ↓
          [ SS49E Hall Sensor + M6x10 Neodymium Magnet ]
                        ↓
         [ ESP32-S3 — 12-bit ADC · Moving Average ]
                        ↓
          [ Normalize → Dead Zone → Hysteresis ]
                        ↓
      ┌─────────────────┴─────────────────┐
      │                                   │
[ USB HID Gamepad ]             [ USB CDC Serial ]
  leftStick axis X                CONFIG / CAL / STATUS
  Button 0 = Shift Down
  Button 1 = Shift Up
      │                                   │
      └─────────────────┬─────────────────┘
                        ↓
         [ Rally Shifter Pro — Python UI ]
           Live telemetry · Tuning · Flash

Hardware

Microcontroller

Parameter	Value
MCU	ESP32-S3 DevKit-C 1
Framework	Arduino (PlatformIO)
USB	Native HID + CDC (simultaneous)
ADC	12-bit (0–4095), 3.3V
Hall pin	GPIO 9 (ADC capable)

Sensor — SS49E Hall Effect

Pin	Connection
VCC	3.3V
GND	GND
OUT	GPIO 9 (ADC)

Full wiring details: docs/wiring.md

Materials

Part	Material
Main body plates	CNC Aluminum 6061
Bushing (M8-10×12)	Graphite self-lubricating bronze
Fasteners	Stainless steel
3D printed brackets / covers	PLA or PETG
Optional enclosure panels	Acrylic

Bill of Materials

See hardware/bom/bom.csv and hardware/bom/bom_explained.md

Firmware

Built with PlatformIO for ESP32-S3.

bash

# Install PlatformIO (VS Code extension recommended)
# Clone and open the repo, then:

pio run                        # build
pio run --target upload        # flash
pio device monitor             # serial monitor (115200)

Serial Protocol

text

PING                → PONG:RallyShifter:1.0
STATUS              → STATUS:<raw>,<axis>,<hyst_state>
CONFIG:{json}       → ACK:CONFIG  |  ERR:JSON
CAL:0..3            → ACK:CAL:<n>
DEFAULTS            → ACK:DEFAULTS

Full protocol: docs/protocol.md

Software (Python)

Desktop companion app — calibration, tuning, and live telemetry.

bash

pip install -r software/requirements.txt
python software/src/main.py

Stack

Library	Purpose
PySide6	Desktop UI framework
pygame	USB HID Gamepad reading
pyserial	CDC serial config/calibration

Assembly Guide

Print or source mechanical parts (see GrabCAD link above)
Machine main plates from aluminum 6061 (or order CNC)
Install F688 flange bearings, bronze bushings, and mold springs
Mount M6×10 neodymium magnet on the crossbar
Mount SS49E sensor aligned with magnet axis (see docs/wiring.md)
Wire ESP32-S3 (3 wires: VCC, GND, signal)
Flash firmware via PlatformIO
Run calibration wizard in desktop app
Plug in and play — recognized as USB Gamepad

Repository Structure

text

rally-shifter-pro/
├── README.md
├── LICENSE
├── .gitignore
├── CONTRIBUTING.md
│
├── docs/
│   ├── images/            ← device photos, UI screenshots
│   ├── protocol.md        ← serial CDC protocol reference
│   ├── wiring.md          ← hall sensor wiring + pinout
│   ├── calibration.md     ← calibration procedure
│   └── design_notes.md    ← technical decisions
│
├── hardware/
│   ├── mechanical/
│   │   ├── source.md      ← GrabCAD credits + link
│   │   └── modifications.md
│   ├── pcb/               ← (future — schematic + gerbers)
│   └── bom/
│       ├── bom.csv
│       └── bom_explained.md
│
├── firmware/
│   ├── platformio.ini

Signal Processing

The firmware applies a 4-stage pipeline on every ADC sample:

text

ADC Read (12-bit) → Moving Average (12 samples) → Normalize (-1.0..+1.0)
        → Dead Zone removal → Hysteresis shift detection

Parameter	Default	Description
`dz_low`	-0.13	Dead zone lower bound
`dz_high`	+0.13	Dead zone upper bound
`thr_down`	-0.62	Shift-down threshold
`thr_up`	+0.62	Shift-up threshold
`hysteresis`	0.10	Return-to-neutral margin

All values are tunable live via the desktop app and persisted to NVS.

License

MIT License — see LICENSE

This project uses and credits the mechanical design published on GrabCAD. All firmware, electronics, and software are original work released under MIT.

Credits

Mechanical design: GrabCAD contributor

Role	Name
Electronics, Firmware & Software	José Pardiñaz
Contributor	Álvaro Martínez
Contributor	Natalia McDonald
Contributor	Alberto Negrete

Made with ☕ in Mérida, Yucatán, MX

Disclaimer

DIY project. No warranty expressed or implied. Build and use at your own risk.

Parts

Qty	Value	Footprint	References
2	Conn_01x03_Socket	Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical	J1, J2
1	ESP32-S3-DevKitC	PCM_Espressif:ESP32-S3-DevKitC	U1

Questions

How big is the Shifter PCB?

It measures 36.7 × 75.2 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Shifter use?

3 parts, built around the ESP32-S3-DEVKITC-1-N8. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Shifter KiCad files?

From the LMHDPRO/open-sequential-shifter repository on GitHub, at the commit this page was made from: the board is hardware/pcb/Shifter/Shifter.kicad_pcb and its schematic hardware/pcb/Shifter/Shifter.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Shifter design in my own project?

Its repository states no licence, so its author keeps all rights: ask LMHDPRO before reusing the design.

Category and platform

ESP32

Topics

diy diy-electronics simracing

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/lmhdpro-open-sequential-shifter" title="Shifter in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/lmhdpro-open-sequential-shifter.jpg" alt="Shifter" width="1200" height="900">

A picture that opens the board, for a README

[![Shifter](https://pcbkit.io/embed/boards/lmhdpro-open-sequential-shifter.jpg?size=s)](https://pcbkit.io/boards/lmhdpro-open-sequential-shifter)

Source

Repository: LMHDPRO/open-sequential-shifter
Board file: hardware/pcb/Shifter/Shifter.kicad_pcb
Commit: 4300c14
Homepage: linkedin.com/in/josepardinaz
Licence: Not stated

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