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nems-tools: Warning Light

Warning Light is a lightweight daemon running on NEMS 1.4.1+. If the state of your monitored hosts should change, Warning Light triggers a visual response by way of a tower signal lamp via GPIO.

  1. OK: Solid green light
  2. WARNING: Solid orange light
  3. UNKNOWN: Flashing orange light
  4. CRITICAL: Short siren every 15 minutes, solid red light.

Warning Light uses nems-api to monitor the status of your NEMS Linux server.

Warning Light can be connected directly to a supported NEMS Linux server, or to a supplemental device running the NEMS Tools Distro with network access, even through the Internet.

System Requirements

Warning Light can be connected directly to a Raspberry Pi, Pine64 and ODROID-based NEMS Linux servers. If your NEMS server is a different platform, you can connect your Warning Light to a supported device (such as a Raspberry Pi Zero) and install the NEMS Tools Distro, which will connect to any NEMS server, regardless of platform.


Pre-Built Kits:

Hey, these prices aren't final. Just waiting to build the prototype and then I'll have a better idea.

GPIO version: $175 USD

Includes everything you need to connect a working NEMS Warning Light to a Raspberry Pi GPIO (not included), fully assembled, soldered, with a 40-pin GPIO cable to connect to your existing Raspberry Pi device.

OOTB Version: $275 USD

The full kit. No other hardware needed. Fully assembled, soldered, and self-contained. Powered by a built-in Raspberry Pi Zero W (not removable - is soldered into the circuit), with Ethernet connectivity.


Buy the parts and build one yourself. Keep in mind this is a “basic” version of Warning Light. The pre-built version is more sophisticated, but the DIY version will work if you're looking to do it on the cheap, or just for the fun of making it yourself.

Log File

You can monitor what is happening with Warning Light by tailing the log file.

tail -f /var/log/nems/nems-tools/warninglight
features/nems-tools/warninglight.txt · Last modified: 2018/09/07 10:27 by Robbie Ferguson