This would print on the Serial the value 1. $3_ {10}$ is represented in binary as $0000011_2$ in a byte. Position 1 is the second bit from the right (think array notation). In order to get the first 4 ...

Binary Nixie Clock with 21 x IN-12 & IN15 Nixie Tubes for Arduino Classic Uno / Nano / Nano IoT 33 / Nano Every etc. - marcinsaj/IN12-IN15-Binary-Nixie-Clock ...

I made this Arduino 8 bit binary led counter as a solution for one member from Arduino forum. He asked if somebody can make a project that displays a decimal number in 8 bit binary format using 8 leds ...