PRJ-01 · Embedded Systems · Hardware · PCB Design · IoT

Hotel Access Control System

A complete embedded hotel room access-control platform designed from the ground up.

01 Overview

A complete embedded hotel room access-control platform designed from the ground up — covering hardware architecture, custom PCB, NFC credential reading, capacitive touch input, wired and wireless networking, and firmware.

02 My Role

Designed and developed the platform end to end: hardware architecture, PCB development, NFC and touch integration, networking, firmware, device identity and testing.

03 System Architecture

PoE / Power—ESP32-WROOM-32E—PN7160 NFC—MPR121 Touch—LAN8720 Ethernet PHY—Wi-Fi fallback—Relay / Door—LED indication—MQTT broker

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04 Hardware

MCU: ESP32-WROOM-32E
Power: Power over Ethernet — add power architecture details
Interfaces: RFID / NFC (PN7160), capacitive touch (MPR121), relay, LED
Communication: Ethernet (LAN8720 / LAN8710), Wi-Fi fallback
PCB: Custom PCB — add layer stack and layout notes

05 Firmware

Language: Embedded C++
Protocols: MQTT over Ethernet / Wi-Fi
Device logic: Credential handling, relay door control, LED states
Lifecycle: Secure device provisioning, OTA firmware updates

06 Engineering Challenges

▸Ethernet PHY integration with PoE power
▸Reliable capacitive touch sensing in an enclosure
▸NFC integration and credential handling
▸Secure device identity and provisioning
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07 Testing & Debugging

OscilloscopeLogic analyserMultimeterProgrammable PSUUART debuggingAdd specific measurements

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08 Result

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09 Tech Stack

ESP32-WROOM-32ECustom PCBRFID / NFCPN7160MPR121EthernetLAN8720 / LAN8710PoEWi-Fi fallbackMQTTRelay door controlLED controlSecure provisioningOTA updatesEmbedded C++

10 Gallery

Enclosure render: capacitive keypad, status LED, do-not-disturb and housekeeping indicators

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