The 5mm Blue LED’s are positioned 30mm apart ... the image below – bottom right – shown passing through NPN transistors). The Arduino Mega 2560 R3 is positioned on a suspended platform ...

in connection with a 10K preset pot attached to the analog input A0 of the Arduino board. This 4 -digit 7-segment display section is wired around four common-cathode 7-segment LED displays, and four ...

Let it hit your red LED and you’ve lost a point ... Inside the cool laser-cut box is an Arduino Uno and a 9V battery, plus a current-limiting resistor and the all-important buzzer.

A teacher I know is stuck, with only npn transistors in the supply cupboard and the need to create a reversible motor drive for an Arduino project. Reversing ‘bridges’ have four switches (relay ...