Receiver board

Lap Timer

Overview

Compact and portable lap timer, capable of measuring time on:

• Closed-loop tracks (1-gate mode)
• Start/finish tracks (2-gate mode)

Infrared light barriers are used as optical triggers to detect when an object crosses the start or finish line.

Key Features

• High accuracy using STM32 hardware timers
• OLED display for showing lap times
• Two operating modes: 1-gate or 2-gate
• Modulated IR system (38 kHz) for ambient light immunity

Project Status

Design: ✅ --> Fabrication & Assembly: ✅ --> Bring-up: ✅

Electronics

Simplified arhitecture of the Lap Timer is shown on the block diagram bellow:

This project contains 3 custom PCBs:

• Timer board: main PCB of the system, responsible for time measurement and displaying results

• Transmitter board: generates the modulated IR light beam for the optical barrier

• Receiver board: (used only in 2-gate mode) detects the IR signal and triggers the timer

Mechanical

Each board has a custom-designed 3D printed enclosure.

Used Tools

• KiCad - Schematic and PCB design
• Autodesk Fusion 360 - 3D modeling
• STM32CubeIDE - STM32 firmware development (build/flash/debug)

Authors

• Dominik Pluta:
  • Responsibility: Timer board
• Mateusz Gwioździk:
  • Responsibility: Transmitter board
• Radek Mierzwa:
  • Responsibility: Receiver board