omnibench

A Rust-based embedded control system for an ESP32-powered test bench with Bluetooth Low Energy (BLE) remote control. The project is split into two binaries: a server that runs on the test bench and controls hardware, and a client that runs on a handheld remote.

out.mp4

3D Printable Parts

• Case
• Cover

Hardware

Remote	Remote (internal)	Server

Features

• BLE Remote Control — Custom GATT protocol connects server and client over Bluetooth LE. The client sends joystick and button events; the server pushes relay state back.
• Relay Control — Controls an 8-relay module over I2C (PCF8574a), with state synchronized to the remote in real time.
• Stepper Motor — Programmable stepper motor driver with smooth acceleration and deceleration ramping, driven via the ESP32 RMT peripheral. Includes a "sticky pedal" fail-safe: if the remote disconnects or stops sending input, the server automatically decelerates the stepper to zero after 500 ms, preventing a runaway motor.
• Joystick Input — Analog joystick on the remote with ADC smoothing, mapped to a signed byte (-127 to 127) for stepper speed control.
• NeoKey Button Panel — Two Adafruit NeoKey 1x4 RGB button matrixes on the remote provides tactile input and color-coded connection status (white = connected, red = disconnected, blue = scanning).
• Low-Power Remote — Deep sleep with wake-on-interrupt keeps the handheld client power-efficient when idle.
• Multi-Board Support — Compile-time pin mappings and ADC calibration for both ESP32 and ESP32-S3 variants.

Project Structure

src/
  bin/
    omniserver.rs   # Test bench controller (server binary)
    omniclient.rs   # Handheld remote (client binary)
  protocol.rs       # BLE message types (RelayState, ButtonEvent, JoystickEvent)
  server.rs         # GATT server: connection handling and notifications
  client.rs         # GATT client: scanning and connection management
  stepper.rs        # Stepper motor driver with ramping
  freq_gen.rs       # Pulse generation via ESP32 RMT
  board.rs          # Board-specific pin and ADC config
examples/           # Calibration and test utilities

Tech Stack

• Language: Rust (2024 edition)
• Target: ESP32 / ESP32-S3
• Key crates: esp-idf-svc, adafruit-seesaw, port-expander, embedded-hal
• Build: Cargo + embuild for ESP-IDF integration