Lauryno torque controller

Torque Sensor Controller for VESC E-Bike Assist

This repository contains hardware and firmware for an ESP32-S3 based torque sensor controller that talks to a VESC over CAN bus.

The controller reads bottom bracket torque and cadence, computes an assist current target, and sends motor current commands to the VESC. It also tracks odometer data with FRAM-backed persistence and exposes a local web UI for status, tuning, and OTA firmware updates.

Features

• Torque and cadence based pedal-assist control loop (10 ms period).
• CAN communication to VESC at 500 kbit/s.
• Odometer and speed tracking with persistent FRAM storage.
• Wi-Fi station mode with fallback access point mode.
• Embedded HTTP console for telemetry, runtime config, and calibration.
• OTA firmware upload endpoint.
• TCP bridge for VESC tool connectivity over Wi-Fi.

Repository Layout

• lauryno_torque_controller_hardware/: KiCad schematic, PCB, and BOM.
• lauryno_torque_controller_software/: PlatformIO firmware project.
• documents/: reference documents, including torque sensor datasheet.
• images/: board render and finished board photo.

Hardware

Hardware highlights:

• ESP32-S3 module as main controller.
• CAN transceiver interface to VESC.
• FRAM storage for high-endurance persistent data.
• 2 MOSFET outputs and a buck stage for front/rear LED lighting.

The PCB was designed to fit AISLER simple 2-layer constraints for low-cost fabrication.

Available hardware design artifacts:

• Schematic: lauryno_torque_controller.kicad_sch
• PCB layout: lauryno_torque_controller.kicad_pcb
• BOM: lauryno_torque_controller.csv

Firmware Architecture

Main runtime modules:

• PedalAssistManager: torque/cadence processing and motor current command generation.
• VescCan: CAN transport and VESC status/current command handling.
• OdometerManager: wheel pulse tracking, speed estimation, and persistence.
• FramStorage: I2C FRAM read/write backend.
• NetworkManager: station connect with timeout and fallback AP startup.
• OtaHttpServer: web UI, REST endpoints, and OTA upload flow.
• VescTcpBridge: optional TCP bridge (disabled by default).

Task model:

• Pedal-assist control task on core 1.
• Communication task (HTTP + TCP bridge update loop) on core 0.
• Main loop polls CAN and updates odometer processing.

Quick Start

First flash has to be done over UART, later ones can be done OTA.

1. Install PlatformIO CLI.
2. Open terminal in lauryno_torque_controller_software/.
3. Create a local platformio.secrets.ini (this file is git-ignored):

[env:esp32-s3-devkitc-1]
build_flags =
	-DWIFI_STA_SSID=\"YOUR_WIFI_SSID\"
	-DWIFI_STA_PASSWORD=\"YOUR_WIFI_PASSWORD\"

4. Build firmware:

pio run -e esp32-s3-devkitc-1

5. Upload over UART (pads at top left of board):

pio run -e esp32-s3-devkitc-1 -t upload

First Boot Notes

• Device tries configured Wi-Fi STA first, then falls back to AP mode if connection times out.
• AP SSID format: TorqueCtrl-Setup-<chipid>.
• mDNS host: lauryno-dviratis.local.
• HTTP console runs on port 80.
• VESC TCP bridge port: 65102 (can be toggled from API/UI).
• Run pedal sensor zero calibration after installation using POST /api/pedal/calibrate_zero.

OTA Update

Firmware can be uploaded from the web UI or directly by HTTP multipart upload:

curl -F "file=@.pio/build/esp32-s3-devkitc-1/firmware.bin" http://lauryno-dviratis.local/api/update

After a successful upload, the controller restarts automatically.

Configuration Baseline

Hardware pins:

• CAN: TX GPIO 15, RX GPIO 7, 500000 bit/s.
• Odometer hall input: GPIO 9.
• FRAM I2C: SDA GPIO 6, SCL GPIO 5, base address 0x50.
• Torque ADC input: GPIO 1.
• Cadence input: GPIO 2.

VESC IDs:

• Local controller 42, target controller 69 (make sure this matches the CAN ID of your VESC).

See lauryno_torque_controller_software/include/app_config.h for the full set of constants and limits.

Open-Source License

This project is licensed under CERN Open Hardware Licence Version 2 - Permissive (CERN-OHL-P-2.0).

See the repository LICENSE file for the project license notice and the official CERN-OHL-P v2 text reference.

References

• VESC firmware project: https://github.com/vedderb/bldc
• Torque sensor reference document: S135daff485444e569ac136541eaddd83u.pdf