One tick is the server, two is the phone, blue is the eyes. How delivery and read receipts travel, why two grey ticks can sit for days, and how to read without blue. Watch the one-minute version first
A 7-segment display is eight LEDs sharing one pin. Common anode vs common cathode, which segments make each digit, resistor values, and Arduino code. Watch the one-minute version first, then read on f
Inside the 555: three resistors set ⅓ and ⅔ thresholds, two comparators watch a capacitor, a flip-flop makes it blink. Astable and monostable, with formulas. Watch the one-minute version first, then r
Mechanical switches bounce for a few milliseconds every press. Here's what that looks like on a scope, and three ways to debounce: a delay, millis(), and an RC filter. Watch the one-minute version fir
A pull-up resistor gives an input pin a definite voltage when nothing drives it. Why a floating pin reads garbage, what value to use, and pull-up vs pull-down. Watch the one-minute version first, then
