Author Upgrades $10 ESP32-C3 Outage Alarm With 12V LED Strips

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

$10 in parts turned the author's easy-to-miss OLED internet monitor into a wall-wide outage alarm that flashes LED strips the moment the WAN connection drops.
An ESP32-C3 Supermini drives two daisy-chained 12V RGB strips through three IRLZ44N MOSFETs and an LM2596 buck converter, letting 3.3V GPIO pins control the lighting from one power supply.
ESPHome handles the PWM light control in YAML, while Home Assistant's built-in internet connectivity checker exposes a WAN status sensor that triggers color changes on disconnect, unavailable or unknown states.
The setup runs fully locally, restores the strips' previous state after power cycles, and doubles as a doorbell and 3D-printer status indicator beyond outage alerts.