Kévin Feltrin

Kévin Feltrin

Data Science & AI @ ESIEE Paris | Physics @ Sorbonne | Co-founder of Reaply

Parking Radar — From Schematics to PCB

A complete hardware build of a parking assistant, going from schematics to a fabricated, routed 2-layer PCB and bench validation.

Project Report (PDF, fr)

What it does

  • Senses distance with a SHARP GP2Y0A21YK0F IR sensor (raw or amplified path).
  • Drives a DC motor/actuator through a Finder 36.11 relay and PN2222A transistor.
  • Speaker output with a selectable first-order RC low-pass filter for tone smoothing.
  • LED bar indicates proximity (three channels).
  • Microcontroller/FPGA-friendly I/O (3.3 V logic, 5 V power domain).

Design highlights

  • Amplifier: LM358 non-inverting stage with adjustable gain (potentiometer), decoupled rails.
  • Protection: flyback diodes on motor & relay, local decoupling (100 nF).
  • Power: single 5 V supply; trace class sized for ~210 mA max on the 5 V net.
  • Board: ~54 × 63 mm, 2 layers, 0 vias (kept simple for fab); labeled jumpers to select raw vs amplified sensor, filtered vs direct audio.
3D render of the assembled PCB
Figure 1. 3D view of the assembled PCB (KiCad 3D viewer).
PCB layout with footprints and routing
Figure 2. Routed layout (2 layers) with clear silkscreen for assembly and test.
Complete schematic: sensor, amplifier, relay driver, speaker, LED bar
Figure 3. Full schematic: sensor front-end, LM358 amplifier, relay driver, speaker path with RC filter, and LED bar.
Photo of the assembled parking radar hardware
Figure 4. Assembled hardware (bench photo).

Notes

  • Put the PDF report at /files/rapport_pcb.pdf.
  • Save the images at:
    • /images/parking-radar-3d.png (3D render)
    • /images/parking-radar-layout.png (layout)
    • /images/parking-radar-schematic.png (schematic)
    • /images/parking-radar-photo.png (real hardware photo)