Lego Sherlock Holmes figure focuses a light beam on a Lego criminal with a small magnifying glass.

Variable Color LED

The Grove Sensor Adapter ( is used in several projects in “High-Tech LEGO,” and another use is shown here in driving a variable color LED from Grove ( The standard LED board from Grove is simply for turning on and off a single-color LED. But Grove also makes an LED board of color that can be changed. This color changeable LED is a red-green-blue LED with the brightness of each of the three constituent colors controlled by three trimpots on the back of the Grove board. A tour of using the Grove Variable LED is in the above video.