Learn robotics by closing the loop
A hands-on course that starts with a blinking signal and ends with a robot that learns from your demonstrations: every lesson pairs readable theory with an interactive lab you can tune, shove, crash and race — then a short quiz locks it in. Halfway through, you tune a line follower from lurching to lapping.
The Loop
0/2What separates a robot from a machine is one idea: sense, think, act — around and around, fast. Meet the loop, and the signal trick that lets a computer whisper to a motor.
Sense, Think, Act: What Makes a Robot
A drill is a machine; a thermostat is almost a robot. The difference is a loop that reads the world before pushing on it — and how often that loop runs decides everything.
PWM: How a Computer Whispers to a Motor
A chip's pin knows only on and off — yet motors need anything in between. The trick is to blink faster than the motor can feel and let the average do the talking.
Motors & Muscle
0/3Everything a robot does to the world, it does through a motor. Learn the three kinds that matter, the four-switch trick that reverses them — and why every motor hides a gearbox behind it.
DC Motors: Fast, Weak and Hungry
Two wires and it spins — but volts buy speed, load steals it, and a stalled motor turns into a heater. Meet the H-bridge, the four switches that give a motor a reverse gear.
Servos & Steppers: Position Without Guesswork
Two opposite answers to 'go to this angle': the servo closes a loop and fights for its position; the stepper counts perfect steps — until it silently loses count.
Gears: Trading Speed for Strength
A motor's speed is a currency, and the gearbox is the exchange booth: ten turns in, one turn out, tenfold the torque — minus a little friction, plus a little wobble called backlash.
Senses & Estimation
0/3Sensors never hand you the truth — they hand you noisy, drifting, cone-shaped hints. The craft is squeezing one honest number out of two dishonest ones.
Rangefinders: Distance by Stopwatch
Ultrasonic and laser rangefinders play the same trick — shout, listen, halve the round trip. The differences that matter are the width of the shout and what the wall is made of.
The IMU: Two Flawed Witnesses
The accelerometer knows which way is down but trembles at every bump; the gyro turns smoothly but slowly forgets where zero was. Neither is fixable — and that's fine.
The Complementary Filter: One Truth from Two Liars
Four lines of code that keep drones level: trust the gyro for this instant, let gravity pull the estimate home over seconds — and one knob, alpha, to split the trust.
Control
0/3The theory of the loop itself: why on/off control must oscillate, how three little terms tame it — and a capstone where you tune a line follower from lurching to lapping.
Feedback: Why On/Off Must Wobble
The simplest controller has two settings and no shame: full power below the target, none above. It works — thermostats prove it daily — and it can never, ever hold still.
PID: Three Letters That Run the World
Push proportionally to the error, remember what refuses to close, brake before you arrive. Present, past, future — every factory floor hums with this one line.
Capstone: Tune the Line Follower
Everything so far on one small robot: sensors report the line, PWM drives the wheels, and your gains decide between lurching, wobbling and one clean fast lap.
Progress & backup
this browser onlyProgress lives in this browser; sync keeps a server copy reachable only by your code, and exports are plain files you own. Imports and links always merge — nothing is overwritten.