You can control the brightness of these LEDs using variable resistors VR1, VR2 and VR3 respectively. Parts Needed. Arduino UNO board – 1 ; 5mm LEDs Red, Green, Blue – each 1 ; 100K Variable resistor – ...

He ended up using multiple 74138 decoder/multiplexer IC’s to control the LED’s. Since the columns have inverted outputs, he couldn’t just hook them straight up to the LED’s.

This article describes the construction of a simple Arduino RFID Access control DIY (Do It Yourself) Project using Arduino UNO and a RFID reader module (EM-18) to control an LED and a Relay. Circuit ...