6-Zone Home Intrusion Alarm Panel with Keypad and Web Dashboard

Homes are protected by single-sensor gadgets that cry wolf, or by commercial alarm panels whose wiring logic is a black box. A real intruder panel is a zone machine: every door, window and room is a zone with a sensor, an end-of-line supervision resistor, an arm state and an entry/exit delay — and understanding that machine is exactly the embedded-systems lesson. This project builds a 6-zone panel on an ESP32: reed switches on doors and windows with 2.2 kΩ end-of-line supervision, HC-SR501 PIRs in living spaces, an MQ-2 smoke sensor as a 24-hour always-active zone, a 4x4 keypad for PIN arming with AWAY / STAY / NIGHT modes, a relay-driven siren, battery backup, and a web dashboard showing zone states and a timestamped event log. The system is an educational prototype, not a certified security product.

1. Each reed zone is wired as a normally-closed loop with a 2.2 kΩ end-of-line resistor; the ESP32 reads SECURE / TRIPPED / TAMPER per zone.
2. Arming from the keypad starts the 45 s exit delay; the user leaves, and the panel arms in the selected mode.
3. On return, opening the entry door starts the 30 s entry delay; the correct PIN disarms before the siren fires.
4. Any armed-zone trip outside the delay fires the relay siren and raises a dashboard alarm banner.
5. The MQ-2 smoke zone is evaluated continuously in every mode — it never disarms.
6. Mains loss switches the panel to battery backup automatically; the dashboard shows the changeover.
7. Every event is timestamped into the dashboard log; the daily self-test chirps the siren and polls each zone.

Tech stack:

• ESP32 (Wi-Fi, Arduino C/C++ firmware)
• 4x4 matrix keypad
• HC-SR501 PIR motion sensors
• Reed switches · 2.2 kΩ EOL resistors
• MQ-2 smoke sensor (educational)
• Relay module · 12 V siren
• Rechargeable battery backup pack
• Local web dashboard (HTML/JS)

• [Six supervised zones] Reed switches on doors and windows, HC-SR501 PIRs in rooms, and an MQ-2 smoke sensor as a 24-hour always-active zone.
• [End-of-line supervision] 2.2 kΩ EOL resistors let the panel distinguish SECURE / TRIPPED / TAMPER on every wired zone.
• [Keypad PIN arming] A 4x4 keypad arms the panel in AWAY, STAY and NIGHT modes; STAY bypasses interior PIRs, NIGHT arms the perimeter plus selected rooms.
• [Entry/exit delays] 30 s entry and 45 s exit delays (design) so legitimate users never trigger the siren.
• [Relay-driven siren] A 110 dB-class siren fires on any armed-zone trip; a daily self-test chirps it and checks every zone.
• [Battery backup] A rechargeable pack keeps the panel alive through mains outages, with voltage reported on the dashboard.
• [Event-log dashboard] Every arm, disarm, trip, delay and self-test is timestamped on the web dashboard, with panel health (RSSI, battery, siren driver) visible.

• Working hardware prototype: ESP32, 4x4 keypad, HC-SR501 PIRs, reed switches with EOL resistors, MQ-2, relay module, 12 V siren, battery pack, demo home rig
• Companion web dashboard (zone states, event log, panel health)
• Firmware with zone supervision, arming modes and delay logic
• Wiring diagram and zone-wiring notes
• Project report PDF (alarm-panel theory, zone supervision, sample event logs)
• PPT presentation for final review
• Viva Q&A preparation document

• Educational prototype, not a certified burglar-alarm system; it must not be sold or presented as one.
• The MQ-2 is a gas/smoke sensor module, not a certified smoke detector; fire safety still needs certified devices.
• The 110 dB siren figure is a typical component rating, not a measured claim.
• Battery reserve (~6 h) is a design target depending on cell capacity and siren duty cycle.
• No professional monitoring or police-dialer function in this build; GSM alerts are future scope.
• The Wi-Fi dashboard is local-network only.