AN OLD WIRED ADT ALARM TURNED INTO A SMART ALARM WITH NO MONTHLY FEE
Your house's old hardwired sensors still work — the box they plug into is what is outdated.
by Smart Home Solver (Reed Kleinman)
HomeAutomation
- difficulty
- ●●●○○
- time
- a weekend
- license
- Apache-2.0
- repo
- repo ACTIVE2,315 stars
●●●○○ · a weekend · Apache-2.0 · 2,315 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
Smart Home Solver turned an old wired ADT/Honeywell alarm into a self-monitored smart alarm with no monthly fee. The hardwired sensors stay; a Konnected conversion kit (ESPHome preinstalled, powered over Ethernet) brings them into Home Assistant, and Alarmo runs the alarm logic. Alarmo is a free, open-source Home Assistant integration installed via HACS and configured entirely from the browser: arm modes (away, home, night, vacation, custom), entry and exit delays, codes and users, sensor watching, notifications and siren actions. For arming, the video uses the Alarmo card on dashboards plus a Ring Gen 2 keypad connected to Home Assistant over Z-Wave and synced with a blueprint. The old wall keypad became a Lenovo Tab M9 running Fully Kiosk Browser, powered from the old keypad wires through a 12V-to-5V converter. The most likely thing to go wrong is false alarms: motion sensors can be tripped by a robot vacuum, and the old window sensors occasionally report open when they are not. Test for a few days before letting it fire the siren automatically. If you already run Home Assistant, the Alarmo part is quick. The hardwired conversion means tracing wires, which a 20-dollar tone generator made easy in the video. This is self-monitored only: no professional dispatch, and no cellular backup in this setup.
IN THE REPO
GOOD TO KNOW
- —Alarmo is a Home Assistant integration installed via HACS, not a standalone device.
- —Alarmo is licensed Apache-2.0.
- —The Alarmo README is comprehensive: UI setup, sensor types, arm modes, codes, automations, MQTT and events.
- —No hardware files: the Konnected kit, keypad, siren and tablet are separate products shown in the video, not part of the Alarmo repository.
- —No official BOM; the hardware depends on what you are converting. The video description links every part used.
- —The video is sponsored by Micro Center and the description contains affiliate links.
Parts to buy
3 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Videos
I Made My Old Security System 100x Better!16:14
Covers Alarmo setup, the Konnected conversion, quirks of the old sensors, mounting and designing the wall dashboard, and the arm/disarm automations.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Install HACS in Home Assistant if not already installed (Required to install Alarmo)
- 2.Add Alarmo via HACS (In HACS, search for 'Alarmo' and install it)
- 3.Restart Home Assistant (Required to load the integration)
- 4.Add the Alarmo integration (Settings, Integrations, add integration, Alarmo)
- 5.Configure sensors, arm modes and codes in the Alarmo panel (The Alarmo panel appears in the Home Assistant sidebar)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- Alarmo is software only. To use old wired sensors you need a conversion board such as the Konnected kit to bring them into Home Assistant.
- No BOM because the hardware depends on your house: which sensors you have, whether they are wired, and which keypad, siren and tablet you choose.
- Self-monitored only: no professional dispatch and, as built in the video, no cellular backup. You get notifications and local sirens, not a call to the police.
- Old wired window sensors can be unreliable: in the video they occasionally reported an open window that was closed. Cameras cover those areas as a backup.
- Motion sensors cause false alarms (a robot vacuum set it off in the video). Camera person detection is more accurate, and you should test for a few days before the siren triggers automatically.
- The hardwired motion sensors sometimes drop offline for a second and come back as on. Trigger light automations on a change from off to on, not just on.
- The Ring Gen 2 keypad is connected to Home Assistant over Z-Wave, not through Ring, so you need a Z-Wave controller in Home Assistant.
Can I use Alarmo without Home Assistant?
No. Alarmo is a Home Assistant integration. You need Home Assistant running before you can install it.
Does this work with my existing wireless sensors?
If they already show up in Home Assistant, yes: you add them in Alarmo and set the right device type (door, window, motion and so on). Sensors that only talk to a closed alarm hub have to be brought into Home Assistant first.
Is there a mobile app to arm/disarm the alarm?
The Home Assistant app works, and Alarmo can send push notifications through it. You can also use the standard alarm panel card or the Alarmo card on a dashboard, and Alarmo supports MQTT for third-party wall panels.
Can I get professional monitoring with this?
No. This setup is self-monitored: you get notifications and can trigger sirens and other automations, but nobody is dispatched. The setup in the video also has no cellular backup yet.
What happens if Home Assistant crashes or loses power?
Alarmo runs inside Home Assistant, so the alarm only works while Home Assistant is running. In the video the network rack sits on a UPS so the alarm keeps working through a power outage.
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Discussion1
FROM THE COMPAREE TEAM
Reed's setup uses a $20 wire tracer to map old sensor wires to the Konnected board, and some of his window sensors are still unreliable. If you have old wired sensors in your house, what would you do differently?
Smart Home Solver (Reed Kleinman)
Reed took the old ADT/Honeywell alarm that came with his new house, kept the hardwired sensors and replaced the brains: a Konnected conversion kit brings the wires into Home Assistant, Alarmo (a free, open-source integration by Niels Faber) runs the alarm, a Ring Gen 2 keypad connects over Z-Wave, and a Lenovo tablet replaced the old keypad on the wall.
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- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM5d ago
Practical notes from our verification: Alarmo is installed via HACS and appears as an integration plus a configuration panel in the sidebar. The README is unusually complete but assumes you already understand Home Assistant entities and HACS. Alarmo is software only: the Konnected kit, keypad, siren and tablet in the video are separate hardware, linked in the video description. Two tips from the video worth copying: power the Konnected board over PoE from a switch on a UPS so the alarm survives a power cut, and run the system on notifications only for a few days before letting it trigger the siren.