Written guides to every DigiCirq video
Electronics, explained one circuit at a time.
Each DigiCirq Short answers one question in about a minute. These articles are the slow version: the same explanation in writing, with the numbers, the diagrams described, and what to try on your own bench.
Latest guides
All articles →How Does an Arduino Actually Work? From Your Sketch to One Pin Going HIGH
What happens between digitalWrite(13, HIGH) and 5 volts on a pin: the compiler, the upload, the bootloader, the ATmega328P, and the one bit in one register that does it.
23 Nov 2026
Why Is My Wi-Fi Slow at Night? (And Slow on One Phone but Not the Laptop)
Wi-Fi slows at night because you share two things: the air in your building and the cable to your street. How channels, airtime and ISP contention work, and what to fix.
22 Nov 2026
WhatsApp Ticks Explained: One Grey, Two Grey, Two Blue, and Why Blue Doesn't Always Mean Read
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.
21 Nov 2026
Why Is My UPS Beeping? (On Battery, Low Battery and Replace-Battery Beeps Explained)
A UPS beeps the instant mains fails because it just switched to its inverter. What each beep pattern means, why it beeps after a new battery, and whether to leave it on.
20 Nov 2026
What Does "Rate Limited" Mean? (Twitter, Discord, APIs and the 429 Error Explained)
Rate limited means you sent requests faster than the service allows, so it refused some. What the 429 error is, how token buckets count, and why apps do it on purpose.
19 Nov 2026
What Is a Flip-Flop Circuit? SR, D, JK and T Flip-Flops Explained
A flip-flop is one bit of memory made from two gates that feed each other. How the SR latch holds a value, what the clock adds, and what D, JK and T flip-flops are for.
18 Nov 2026
Series
Breadboards, resistors, capacitors, timers and displays — the parts every project is built from.
5 guides
Flip-flops, decoders, encoders: how ones and zeros become memory and decisions.
1 guide
What really happens between your sketch and a pin going HIGH.
1 guide
Why the lights dim, why the breaker trips, why your phone dies at 15%.
4 guides
Queues, rate limits, ticks and traffic colours: the system design behind the apps on your phone.
2 guides