A servo-mounted ultrasonic sensor turns a two-wheel chassis into the smallest build that contains a whole robot: sense, decide, act. Here’s how the sweep-and-pivot loop works, the HC-SR04 limits to design around, and what to buy for either route.
The L298N is the default motor driver in beginner robotics and, by modern standards, a genuinely inefficient chip. Here is what it does well, the voltage drop and 5V jumper that bite people, and when to switch to a TB6612FNG instead.
Your first sensor reading isn’t magic — it’s a voltage, measured 10 bits at a time. Here’s what analogRead() actually returns, why a photoresistor is useless without a partner resistor, and how to get numbers out of the Serial Monitor that mean something.
Most beginner robots fail on power, not code. Here’s what voltage, current, and capacity each actually control, why your board resets when the motors spin up, and the three parts that fix it.
A Bluetooth robot car is the shortest path from breadboard tinkering to something that actually drives across your floor. Here are the four parts that matter, the one resistor divider that keeps your HC-05 alive, and the power mistake that looks like a code bug.
Most beginner soldering kits are one decent iron surrounded by filler. Here is what actually decides whether a kit is worth buying — temperature control, thermal recovery, and the solder in the box — plus three picks, including the cheap upgrade that fixes more joints than a new iron would.
A dead motor is almost never a code problem. Here is the checklist in order of likelihood, starting with the L298N voltage drop and the enable pins that quietly kill more beginner builds than anything else.
The Arduino Mega isn’t the brain of a retro arcade cabinet — a Raspberry Pi is. It’s the part that makes the cabinet feel alive: lit buttons, an RGB marquee, a coin door that clicks. Here’s the division of labor these builds actually run on, and the USB gotcha that catches almost everyone.
The SG90 is in every starter kit and still costs about two dollars, but plastic gears and a 500-700 mA stall current set hard limits on what it can do. Here’s exactly where it still wins, where it fails, and when the metal-gear MG90S is worth the swap.
Arduino is a microcontroller; Raspberry Pi is a computer. Here’s what that actually means for your project, why the Pi has no analog pins, and which one to buy first.