ESP32 Barcode Scanner Case – Under-Cabinet Mount

A compact under-cabinet enclosure for a DIY barcode scanner that adds groceries to your shopping list. Mount it under a kitchen cupboard, point a product at the scanner window below, and press the button — the item appears on your Mealie shopping list.

What's Inside

• ESP32 DevKit on a 40 × 60 mm perfboard
• GM67 barcode scanner module — faces straight down through the bottom opening
• SSD1306 0.96″ OLED display — visible through a front cutout, shows scan results
• Tactile push button — 10 mm, front face, easy thumb press

The Case

Three printed parts — an outer shell, an internal chassis (inset), and a small button cap.

The inset holds all electronics and slides into the outer case via matching 45° bevels for a clean, seamless fit. Four mounting ears with countersunk screw holes attach the case to the underside of a cupboard or shelf.

Dimensions: 100 × 36 × 52 mm (100 × 56 mm with mounting ears)

Print Settings

• Material: PLA or PETG (PETG recommended for kitchen use)
• Layer height: 0.2 mm
• Infill: 15–20%
• Standard slicer defaults, no special settings

Hardware

Fasteners:

- 8× M1.7 × 5 mm screws (electronics mounting)
- 4× 3.5 × 18 mm countersunk wood screws (cupboard mounting)

Tools:

- PH0 + PH2 screwdrivers
- Perfboard saw or Dremel + file (to cut the button carrier board to 27.5 × 17 mm)
- Safety goggles

Assembly

A specific assembly order is required due to the compact design — some parts lock against each other. Full step-by-step instructions →

Quick summary:

1. Slide scanner into inset, screw in
2. Seat ESP32 on perfboard, slide into inset slots, screw in, connect scanner cable
3. Slide display into front slot, screw in
4. Lower inset into outer case
5. Tilt forward, drop in button cap
6. Slide button carrier board into slots (friction fit)
7. Plug in USB, mount to cupboard

Part of a Larger Project

This case is part of mealie-barcode-middleware — a self-hosted barcode scanning system for Mealie grocery management. The project includes:

• ESP32 firmware (ESPHome) — handles scanning, display, and communication
• Middleware (FastAPI + web dashboard) — barcode lookup, fuzzy matching, shopping list management
• Full documentation — hardware build guide, wiring diagram, firmware setup, and more

Everything runs locally on your home network. No cloud, no subscription.

Links:

• GitHub — Full Project
• Hardware Build Guide
• Assembly Instructions