Snack Cart POS
Materials
| Item | Use | Quantity | Price |
|---|---|---|---|
| ESP32-S3-N16R8 dev board (Mingwu) | Main microcontroller — runs the UI, database, and WiFi stack | 1 | $9.00 |
| KMRTM35018-SPI 3.5" 480×320 ILI9488 display | Primary UI display, portrait orientation (touch controller present but unused) | 1 | $9.00 |
| Tactile pushbutton (Up/Down/Left/Right/Enter/Back) | Physical D-pad input, replaces the unused touchscreen | 6 | $1.00 |
| GM65 2D barcode scanner module | Scans employee badges and item barcodes | 1 | $18.00 |
| MicroSD card | Stores the SQLite database (users, items, checkouts) | 1 | $4.00 |
| DS3231SN RTC + CR2032 battery | Keeps wall-clock time across power loss, for checkout timestamps | 1 | $3.00 |
| USB wall wart + USB breakout board | 5V power only, no data | 1 | $4.00 |
| Physical WiFi toggle switch | Hardware kill-switch for the admin WiFi access point | 1 | $1.00 |
| Reset tactile switch | Hard reset, wired to RST pin | 1 | $0.50 |
| Baltic birch plywood | Enclosure body — angled front face, weighted base to counter tip | 1 | $5.00 |
| PETG filament | 3D-printed bezels and brackets as needed | 1 | $0.50 |
| Total | $55.00 | ||
* All prices are rough estimates at time of build and do not represent exact prices spent, due to bulk ordering and timing.
Tools Used
- PlatformIO / Arduino framework
- TFT_eSPI (Bodmer)
- LVGL 8.4.0
- Sqlite3Esp32
- ESPAsyncWebServer + AsyncTCP
- ArduinoJson