LightMe App


Turning house lights on when night falls and graphing the light variation over time.

Light level is displayed as a % and arbitrarily categorised as Dark, Dim, or Bright. The LED is switched on when Dark. The Gravity sensor has a detection range from 1-6000 Lux.

Examples of light levels: Very Bright Summer Day 100,000 Lux; Full Daylight 10,000 Lux; Overcast Summer Day 1,000 Lux; Very Dark Day 100 Lux; Twilight 10 Lux; Full Moon< 1 Lux

Accessories (Gravity)

Analog Ambient Light Sensor: DFR0026

Digital White LED Light Module: DFR0021-W


Construct a cardboard house with the light sensor mounted on the roof, and a LED in a window. The LED can be turned on and off (simulating day and night) by holding a hand between sensor and light source.

  • Plug the chosen light sensor into plug P4
  • Plug the LED into Plug 2
  • Logging of light level starts as soon as app is switched on; and off when it is exited
  • The sampling interval has a default of 2 secs in the initial Kappconfig.txt file. For longer sampling period, ie, every 10 seconds, edit the file in the flash memory with any text editor for a duration of 10 seconds.
  • The Kooklog Excel file in the USB drive store can be uploaded to a PC for analysis


  1. Import initial conditions from the Kappconfig.txt file via the file
  2. Create the analog and digital input and output,and turn off radio to conserve power
  3. Read the light sensor and categorise the value into Dark, Dim and Bright
  4. Commence data logging
  5. If Dark, switch the LED on.
  6. If Bright, switch the LED off
  7. If Dim, leave the LED in its current state
  8. On exit, switch the LED off and cease data logging
John Phillips