Power Checker

By Karel Cermak | Karlosoft.

A simple Arduino project to monitor the power supply state in the electrical network and the backup power supply.

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Features

• Checks the functionality of the power system and the power supply of the backup power supply via USB.
• It changes the status LEDs responding to the current status.
• Controls a buzzer that will be triggered if the backup power supply is disconnected.
• Generate simple JSON statistics via the integrated web server.
• DHT temperature sensor and buzzer / ceiling light mute button.

States of the system

• Everything ok (1)

  • Blue light slowly blinking
  • Orange light off
  • Red light off

• DHT temperature sensor error (2)

  • Blue light blinking fast
  • Orange light slowly blinking
  • Red light off

• Ethernet error (3)

  • Blue light blinking fast
  • Orange light off
  • Red light slowly blinking

• Main grid off (4)

  • Blue light off
  • Orange light blinking fast
  • Red light off
  • Ceiling light turned off

• Backup power supply off (5)

  • Blue light off
  • Orange light off
  • Red light blinking fast
  • Ceiling light turned on
  • Buzzer activated

How to stop the buzzer and the ceiling light?

• Hold button for 0.5 seconds

  • Deactivate the buzzer for 30 minutes

• Hold button for 5 seconds

  • Deactivate the buzzer and ceiling light for 12 hours

Known problems with W5100 ethernet shield:

• If it is necessary to restart the Arduino via the restart button to get the web server working, this might help:
  • Put a 100 nF capacitor between the RESET and GND pins (a larger capacitor should also work).
  • Place 100 ohm resistors between ethernet pins 1-2 and 3-6 (not tested).