Author Builds $5 ESP32 Outage Alarm With LED Strips for Instant Internet Alerts

Q: Why don't routers have a simple light to show internet status, forcing users to build their own alarms?

Routers generally do have an internet-status light, but it is usually a small WAN/Internet LED meant for basic diagnostics, not an unmistakable alert. On many consumer models, a solid green or white light means the internet is up, flashing shows traffic, and red, orange, or off can mean the connection is down. So the issue is less that routers lack a status light and more that the built-in indicator is easy to miss and often requires interpretation. Manufacturers design router LEDs to serve several purposes at once: power, Wi‑Fi, LAN activity, WPS, and WAN status. That keeps hardware simple and cheap, but it also means the internet indicator is just one tiny light among many. It is passive by design. Users have to look at the router, know what the color or blink pattern means, and often remember that meanings vary by brand. That is why some users build their own alarms. The DIY project in the news turns room lighting into a large, immediate signal that cannot be overlooked. Using Home Assistant’s WAN monitoring and an ESP32-controlled LED strip, it creates a proactive alert rather than a diagnostic hint. It also works locally, without cloud services or subscriptions. In practice, router makers optimize for low cost, minimal complexity, and broad usability, while enthusiasts optimize for visibility and instant awareness. The gap is not the absence of status lights; it is the difference between a small troubleshooting LED and a true outage alarm.

1 articles · Updated · MUO - MakeUseOf · Jul 14

$5 in parts turned an ESP32 and 12V RGB LED strips into a bright internet-outage alarm that flashes the moment a WAN connection drops.
Three IRLZ44N MOSFETs and an LM2596 buck converter let the ESP32's 3.3V pins control the strip's 12V color channels from a single power supply.
ESPHome and Home Assistant handle the logic: a built-in WAN status sensor triggers color changes when the connection shifts from Connected to Disconnected, Unavailable or Unknown.
The upgrade replaces an earlier $10 ESP32 alarm with a 1.13-inch OLED display that proved too easy to miss, making the new version visible across the room.
Because the setup runs locally and can restore the LEDs' prior state after power cycles, it doubles as a low-cost smart-home status light beyond outage alerts.