Source: https://mokxi.com/learn Updated: 2026-09-27 Signed out Only in this browser 0 days Level 1 # Spark 0 XP. 50 to Spark. Start Electronics basics: Build your first circuit Make an account ## Today Daily challenge +50 XP ### Watch the input PB0 has to go low Reading a pin Take it 0/5 This week 0 XP ### 5 steps to go Paths ## Pick a path Whether you are just starting out or building on what you already know, each one is chapters of lessons, ending in a project you actually finish. ### Electronics basics 7 h A breadboard and a few parts, with one Uno blink at the start and no processor after it. What current, voltage, time and logic really do. 6 chapters 14 lessons 0 of 14 done ### Embedded on the Arduino Uno 12 h One board, twenty pins and a C++ sketch. From a lamp you switch to a game you can play. Arduino Uno R3 9 chapters 16 lessons 0 of 16 done ### Embedded on the ESP32-C3 11 h A 32 bit RISC-V board at 160 MHz. Its own peripherals, its own 3.3 V rules, and a console at the end of it. ESP32-C3-DevKitM-1 7 chapters 13 lessons 0 of 13 done ### Embedded on the Raspberry Pi Pico 6 h A dual core Cortex-M0+ at 125 MHz. PWM on every pin, a 64 bit clock, and pins that do not forgive 5 V. Raspberry Pi Pico 4 chapters 7 lessons 0 of 7 done ### Embedded on the STM32F411 6 h A Cortex-M4 at 84 MHz, where a pin is a port and a number and every peripheral starts with its clock switched off. STM32F411 Black Pill 3 chapters 6 lessons 0 of 6 done ### C++ on a board 10 h The language, one idea per lesson, on a board that shows you what your code did. Arduino Uno R3 5 chapters 13 lessons 0 of 13 done ### Digital logic and memory 4 h Build logic from individual gates, then make a bit persist, count and move through a register. 2 chapters 4 lessons 0 of 4 done ### Interactive devices on the Uno 8 h Read people and sensors without blocking, control an output, then finish with two playable builds. Arduino Uno R3 4 chapters 9 lessons 0 of 9 done ### From gates to a computer 16 h Start with one NAND gate, package every circuit you build into a chip, and use your chips to build the next one: an adder, memory, a CPU of your own, and a computer that runs your program. 6 chapters 23 lessons 0 of 23 done ### The twelve week course 24 h The classroom course, week by week: a loop on a breadboard through to a board talking over serial. 3 chapters 12 lessons 0 of 12 done ## This week Experience earned since Monday, by the people who checked the box. The weekly board needs an account. Make an account See the all-time top levels ## Badges ### First light Light an LED. Wire one up, press Run and watch it come on. Not yet ### Compiled in the browser Compile your own code. Press Run on a board with a sketch in the editor. Not yet ### 555 astable Get a 555 running. Its output has to go high and low on its own. Not yet ### Found the fault Fail a Check, work out why, and pass it. Not yet ### Every board Run the Uno, the ESP32-C3, the Pico and the STM32 at least once each. Not yet ### Lesson published Write a lesson in the editor and publish it. Not yet ### In a class Join a class with the code your teacher gives you. Not yet ### Seven days Pass a step on seven days in a row. Not yet ## Achievements ### First wire Drag from one pin to another. Not yet ### First Run Press Run. Not yet ### Ten parts Build something with ten parts in it. Not yet ### Four families Place the Uno, the ESP32-C3, the Pico and the STM32. Not yet ### Night owl Run something between midnight and four in the morning. Not yet ### Early bird Run something between four and seven in the morning. Not yet ### It spoke Get a board to print something. Not yet ### Long run Leave a simulation going for a minute of its own time. Not yet ## Read the basics Here to meet you wherever you are: the longer tutorials and the roundups each also come as a one-page PDF lesson plan you can download and hand to a class. ### Tutorials and explainers Connect a Board to WiFi and Serve a Page How to Use a Breadboard: Your First Circuit Ohm's Law, in a Circuit You Can Run Picking a Resistor for an LED Pull-Up Resistors and the Floating Input They Fix Debouncing a Button: Why It Fires More Than Once PWM: Faking an Analog Voltage on a Digital Pin The 555 Astable: Timed by a Capacitor, Not a Crystal Logic Gates, and the Truth Table You Can Press Shifting a Byte In, One Edge at a Time Blink an LED with Arduino: Wiring and the Resistor Arduino Button Debounce: See the Bounce, Then Fix It Arduino Blink Without Delay: Two LEDs, Two Rates Arduino PWM Fade: analogWrite, Pins and the Curve Blink an LED on the ESP32-C3, Step by Step Blink an LED with a 555 Timer, No Microcontroller Arduino Simulators Compared: An Honest Roundup How to Simulate an Arduino Project Without Hardware Measure It: Read a Circuit With a Scope and Plotter UART Serial Explained: Baud, Frames and the Wire I2C Explained: Addresses, Pull-Ups and a Scanner SPI Explained: Clock, Data and Chip Select Interrupts vs Polling on Arduino, Side by Side Arduino State Machine: A Four-State Reaction Game ESP32 HTTP GET Request: Fetch the Weather as JSON ESP32 analogRead: 12 Bits, Attenuation and ADC2 Raspberry Pi Pico PWM: Slices, Channels and 1 kHz STM32 Blue Pill Blink with Registers, Not pinMode Arduino Uno vs ESP32 vs Pico: Which to Learn First? Multisim Live Is Gone: A Chromebook Alternative Digital Electronics on Chromebooks: Labs by Unit Half Adder and Full Adder: Truth Table to Breadboard Flip-Flops Explained: SR Latch, D and JK Flip-Flops Science Olympiad Circuit Lab Study Guide, B and C Circuit Lab Practice Test: 30 Measured Questions How to Use a Multimeter: Practice on a Virtual One Arduino Science Fair Projects With a Real Hypothesis Reaction Time Science Fair Project With an Arduino Engineering Science Fair Project: How to Write It Up 555 Timer Projects for a Science Fair (No Coding) Circuit Lab Division B: Middle School Starter Guide SkillsUSA Electronics Technology Practice Circuits TSA Electrical Applications: Practice Circuits Arduino Simulator for Chromebook, Free in Chrome Free Circuit Simulator for High School Classes Arduino Projects for Beginners, Each One Running Online SPICE Simulator: Run and Export Netlists Arduino LED Not Lighting Up or Dim: What to Check Arduino Compile Errors Explained, With the Fixes How to Debug Arduino Code: Prints to Breakpoints Resistor Color Code Calculator and Chart Arduino Relay Module: Active LOW and Startup Clicks How Many LEDs Can One Arduino Pin Drive? Arduino I2C LCD Not Working: Blank, Blocks, No Text Build a Computer From NAND Gates, Step by Step ### Electronics fundamentals, each with a circuit to poke Voltage Dividers and Why They Are Bad Power Supplies Series vs Parallel Circuits, Seen With LEDs The RC Time Constant, on an Oscilloscope PWM to an Analog Voltage With an RC Filter Diodes for Reverse Polarity Protection An NPN Transistor as a Switch, Driving a Motor The Flyback Diode, and the Spike It Stops MOSFET vs BJT: Which Transistor to Switch With Analog vs Digital Pins, and ADC Resolution The 555 Monostable: One Press, One Timed Pulse An Op-Amp as a Comparator, With Hysteresis The Non-Inverting Op-Amp Amplifier, on a Scope ## Project tutorials The Arduino projects everybody builds, from a traffic light to an ultrasonic sensor, each one running at the top of its page with the wiring, the code and the common mistakes. Arduino Traffic Light with a Crossing Button Arduino Servo Motor with a Potentiometer Arduino Ultrasonic Sensor (HC-SR04) Tutorial Arduino I2C LCD 16x2: Wiring and Code Arduino DHT22 Temperature and Humidity Sensor Arduino 4x4 Keypad Code Lock with a Relay Arduino 7 Segment Display: an Electronic Die Arduino Stepper Motor: 28BYJ-48 and ULN2003 Arduino OLED Display (SSD1306) Tutorial Arduino MPU6050: Accelerometer and Tilt Arduino Potentiometer: analogRead and a Dimmer Arduino LDR Night Light (Photoresistor) Arduino IR Remote: Decode NEC, Switch Lamps ESP32 NeoPixel (WS2812B) Rainbow Tutorial Arduino Joystick Module: Wiring, Code, Live Demo Arduino TMP36 Temperature Sensor in °F and °C Arduino L293D Motor Driver: Forward and Reverse Arduino Buzzer and Piezo: Beeps, Notes, Metronome Arduino MAX7219 8x8 LED Matrix: Wiring and Code Arduino DS3231 Clock With a TM1637 Display PIR Motion Sensor: How It Works, With an Arduino ## How it works When does a day end? At midnight UTC, the same moment for everybody. What breaks a streak? A day with no step passed. One missed day is covered if you hold a freeze. How do I get a freeze? Seven days in a row earns one, at most one a week. What is a boss? The last lesson of a chapter. It opens when the rest of the chapter is done and pays twice. Where is my progress kept? In this browser, and on your account as well when you have one. Signing in keeps the higher of the two. Who sees the leaderboard? Anyone can see the all-time board at /leaderboard, and only people who check the box are on it. It shows a name, level and XP, never an email. Students in a class are not listed there.