Source: https://mokxi.com/curriculum Updated: 2026-09-27 For teachers and professors # A 12-week electronics course where every circuit already runs An introduction to electronics and embedded programming, mapped week by week to circuits you can open right now, whether your class has never touched a breadboard or is already building on real skills. Nothing to buy, nothing to install, and it runs the same on a school Chromebook as on a lab machine. Start at week one How a lesson runs What it costs Hold the button The first circuit of the course, running as you read. Click it to open it in the editor. ## The course at a glance Twelve weeks, each with a circuit that runs today and parts that are already in the bin. Week Topic Circuit to open Parts 1 Current, voltage and the breadboard Hello, breadboard breadboard, power and ground, slide switch, resistor, LED 2 Blink: the first program Arduino Uno blink Arduino Uno R3, breadboard, resistor, LED 3 Buttons, pull-ups and contact bounce ESP32-C3 button ESP32-C3-DevKitM-1, pushbutton, resistor, LED, breadboard 4 Timing without a processor: the 555 555 blinker NE555, capacitor, resistors, LED, slide switch, breadboard 5 Logic gates, as real chips Gate lab 74HC08, 74HC86, 74HC04, pushbuttons, resistors, LEDs, breadboard 6 Arithmetic from gates: the full adder Full adder 74HC86, 74HC08, 74HC32, slide switches, resistors, LEDs, breadboard 7 Memory: flip-flops and counters Binary counter 74HC74 (two), clock, resistors, LEDs, breadboard 8 More outputs than pins: the shift register LED bar chaser Arduino Uno R3, 74HC595, resistors, eight LEDs, breadboard 9 Pulse width modulation and the eye Breathing LED ESP32-C3-DevKitM-1, resistors, capacitor, LEDs, breadboard 10 Serial: making the board talk ESP32-C3 serial ESP32-C3-DevKitM-1 11 Interrupts: events instead of polling Reaction timer Arduino Uno R3, pushbutton, piezo, buzzer, resistors, LED, breadboard 12 Project week: two boards, one wire Two boards, one wire ESP32-C3-DevKitM-1, Arduino Uno R3, resistors, LEDs, breadboard ## The twelve weeks Each week gives you what a student should be able to do, the circuit to open, one exercise and one way to grade it. The assessments are suggestions rather than a scheme. Week 1 ### Current, voltage and the breadboard One loop: a supply, a switch, a resistor and an LED, wired on a real breadboard. #### They will be able to - Trace a complete circuit as a loop from the supply and back to it - Wire parts into a breadboard so the strips make the connections you meant - Explain why an LED needs a series resistor, and work out the current from the supply, the forward drop and the resistor #### Exercise #### Assessment idea A wiring diagram of their own loop with the current calculated for their chosen resistor, submitted as a link to the running circuit. Parts: breadboard, power and ground, slide switch, resistor, LED Read more: Ohm's Law, in a Circuit You Can Run · Picking a Resistor for an LED · Series vs Parallel Circuits, Seen With LEDs · Voltage Dividers and Why They Are Bad Power Supplies Download the lesson plan (PDF) Week 2 ### Blink: the first program A board, a pin and a program: digitalWrite and delay on a real Arduino Uno model. #### They will be able to - Set a pin as an output and drive it high and low from code - Use delay() and relate 500 ms in the sketch to 500 ms of simulated time - Find the compile errors the editor reports and fix them #### Exercise Change the blink to 100 ms and confirm the speed readout still says 1.00x. Then add a second LED on another pin and try to blink it at a different rate with delay() alone. Write down why it cannot be done that way. #### Assessment idea A blink pattern written to a spec (three short, three long, three short), graded by opening the shared link and watching it run. Parts: Arduino Uno R3, breadboard, resistor, LED Download the lesson plan (PDF) Week 3 ### Buttons, pull-ups and contact bounce Why an input must never float, and why one press can be counted three times. #### They will be able to - Wire a button with an internal pull-up and explain why the pin reads low when pressed - Observe contact bounce as extra edges, not as a fault in the code - Debounce in software with millis, and say what the delay you chose costs #### Exercise Hold the button and watch the LED. Then pick the interrupt example in the board's Firmware panel, press ten times and record the count it prints; the pushbutton's contacts really bounce, so the number will be too high. Set the button's bounce property to worst and repeat, then write a millis debounce and repeat again. #### Assessment idea A table of presses against counted edges for bounce set to none, typical and worst, plus the debounce code that brings the count back to the number of presses. Parts: ESP32-C3-DevKitM-1, pushbutton, resistor, LED, breadboard Read more: Pull-Up Resistors and the Floating Input They Fix · Debouncing a Button: Why It Fires More Than Once · Analog vs Digital Pins, and ADC Resolution Download the lesson plan (PDF) Week 4 ### Timing without a processor: the 555 An RC network sets the rate and a 555 turns it into a square wave. #### They will be able to - Explain what a capacitor charging through a resistor does over time - Use f = 1.44 / ((R1 + 2 R2) C) to pick parts for a rate you want - Trade resistance against capacitance for the same frequency and say why you would pick one #### Exercise Click the switch to change gear and count the blinks against a clock. Then choose R and C for a one second blink and for a five per second blink, build both, and measure them. Finish by opening the doorbell circuit, where the button gates the 555's reset pin instead of switching the load. #### Assessment idea Predicted against measured frequency for three different R and C pairs, with a sentence on the error. Mokxi integrates the capacitor in steps, so expect the measured rate to sit within a couple of percent of the formula rather than exactly on it. Parts: NE555, capacitor, resistors, LED, slide switch, breadboard Read more: The RC Time Constant, on an Oscilloscope · The 555 Astable: Timed by a Capacitor, Not a Crystal · The 555 Monostable: One Press, One Timed Pulse Download the lesson plan (PDF) Week 5 ### Logic gates, as real chips AND, OR, XOR and NOT on 74HC chips with supply pins and propagation delay. #### They will be able to - Fill in a truth table by driving the inputs of a real gate - Read a DIP pinout and wire VCC and GND before anything else - Explain why a CMOS input needs a pull-down and what an unpowered chip does #### Exercise Press the two buttons in all four combinations and fill in the table for AND, XOR and NOT. Then take one chip's VCC wire out and record what the output does. Build the same gate twice, once with the ideal gate part and once with the 74HC chip, and describe the difference. #### Assessment idea A completed truth table sheet plus one paragraph on what the real chip has that the ideal symbol does not: a supply, a threshold that follows it, a propagation delay and a high impedance state when it is off. Parts: 74HC08, 74HC86, 74HC04, pushbuttons, resistors, LEDs, breadboard Download the lesson plan (PDF) Week 6 ### Arithmetic from gates: the full adder Two XORs, two ANDs and an OR add one bit and carry into the next. #### They will be able to - Add binary numbers by hand and name the sum and carry columns - Derive sum = A xor B xor Cin and carry = AB + (A xor B)Cin - Follow a signal through three chips and check each stage against the table #### Exercise Set A, B and the carry-in on the three switches and complete all eight rows of the truth table. Then draw what a second bit would need and mark where the carry goes. #### Assessment idea The eight-row table, plus a hand-drawn two-bit ripple-carry adder with the carry chain marked and the number of gates counted. Parts: 74HC86, 74HC08, 74HC32, slide switches, resistors, LEDs, breadboard Download the lesson plan (PDF) Week 7 ### Memory: flip-flops and counters A D flip-flop wired to toggle divides a clock by two; four of them count. #### They will be able to - Explain what makes a flip-flop different from a gate: it holds a bit - Wire a D flip-flop as a toggle and show that it halves the clock - Read four LEDs as a binary number and explain the ripple delay between stages #### Exercise Set the clock to 1 Hz and write the four LEDs down as binary for sixteen steps. Then take one stage's clock from Q instead of Q-bar and record what happens to the direction. #### Assessment idea The sixteen step count sequence, plus a sentence on why the stages do not all change at the same instant and why a real design uses a synchronous counter. Worth saying in class: Mokxi powers a 74HC74 up cleared so a circuit built from toggles starts somewhere known, where a real chip powers up at random and needs a reset. Parts: 74HC74 (two), clock, resistors, LEDs, breadboard Download the lesson plan (PDF) Week 8 ### More outputs than pins: the shift register Three pins in, eight out: a 74HC595 shifting a byte and latching it. #### They will be able to - Describe serial in, parallel out in your own words - Name what the data, shift clock and latch clock pins each do - Explain why the latch is pulsed once after eight bits and not after each one #### Exercise Change the pattern to a binary count from 0 to 255. Then move the latch pulse inside the bit loop and describe what the LEDs do. Finish by opening the electronic dice, where the same idea drives a seven segment display. #### Assessment idea Their own pattern function running, with a short explanation of what the latch buys and what MR and OE are tied to. Parts: Arduino Uno R3, 74HC595, resistors, eight LEDs, breadboard Download the lesson plan (PDF) Week 9 ### Pulse width modulation and the eye One pin switching fast enough that a fraction of the time looks like a fraction of the brightness. #### They will be able to - Define duty cycle and work out the average of a square wave - Tell hardware PWM from software PWM and say which pin gives which - Predict what an RC low-pass filter does to a 1 kHz square wave #### Exercise Watch the two branches: one LED sees the raw chopping, the other sees it through a filter. Change the brightness table to a straight ramp and say why it looks as though it rushes the top end. Change the filter capacitor and describe the effect. #### Assessment idea A short write-up of duty cycle against perceived brightness, comparing the Uno's hardware PWM on timer 1 at 490 Hz with the ESP32-C3 example's software PWM at 1 kHz. Parts: ESP32-C3-DevKitM-1, resistors, capacitor, LEDs, breadboard Read more: PWM: Faking an Analog Voltage on a Digital Pin · PWM to an Analog Voltage With an RC Filter Download the lesson plan (PDF) Week 10 ### Serial: making the board talk Printing to the monitor, reading what is typed back, and the time a baud rate costs. #### They will be able to - Open a serial connection and print values from a running sketch - Read characters back in and act on them - Explain why printing a long line takes real time at a given baud rate #### Exercise Print the uptime, then type into the monitor and watch it echo. Change the baud rate and describe the difference. Then open the reaction timer, play twenty rounds and collect the numbers it prints. #### Assessment idea A data set of their own, twenty readings with a mean and a range, submitted with the sketch that produced it. Parts: ESP32-C3-DevKitM-1 Download the lesson plan (PDF) Week 11 ### Interrupts: events instead of polling A handler that runs the moment a pin changes, and the rules that come with it. #### They will be able to - Say what an interrupt handler is and when it runs - Attach a handler to an edge on a pin and share a value with the main loop safely - Explain why a long delay() loses events that an interrupt would have caught #### Exercise Read the reaction timer: it polls the button in a loop. Rewrite it so the button is on an external interrupt, using the shipped interrupt example as the reference. Then open the traffic light and explain why its wait lamp lights the instant you press, even though the sketch is inside a five second delay. #### Assessment idea The interrupt version running, plus a paragraph on what volatile is for and why the loop takes its copy with interrupts off. Parts: Arduino Uno R3, pushbutton, piezo, buzzer, resistors, LED, breadboard Download the lesson plan (PDF) Week 12 ### Project week: two boards, one wire Plan a system, agree a protocol, share a ground, and present it as a link. #### They will be able to - Plan a build as inputs, processing and outputs before wiring anything - Agree a simple protocol between two boards and implement both ends - Explain why two boards that talk must share a ground #### Exercise Open it and watch one board pulse a number down a single wire while the other counts the edges and prints it. Extend the protocol so a message carries two numbers, and make the receiver say something when what arrived makes no sense. #### Assessment idea A working project shared as a link, a wiring diagram, and a two minute demonstration to the class of what it does and what went wrong on the way. Parts: ESP32-C3-DevKitM-1, Arduino Uno R3, resistors, LEDs, breadboard Download the lesson plan (PDF) In the room ## How a lesson runs Five minutes of setup for the whole class, and none of it needs an administrator to sign anything off. - You build the starting circuit Open the week's circuit, change it into the one you want the lesson to begin from, and save it. Half wired if the lesson is about wiring, fully wired if the lesson is about code. - You assign one link Share the project and put the link on the board or in the class page. Everyone opens the same circuit. Nobody signs up, nobody installs anything, and no administrator has to approve anything. - They work on the machine they already have A school Chromebook, a laptop, a borrowed machine or a phone. The simulation runs on their own device, so thirty students at once is thirty machines working and nothing queued on a server. - They break it, safely A reversed LED and a shorted rail cost nothing. Where the circuit is genuinely undefined, Mokxi shows an unknown level rather than guessing at one. - They share it back as a link A student makes their project public and sends you the link. It opens and runs for you exactly as it ran for them, so the submission is the working circuit rather than a screenshot of it. - The timing is real A 500 ms delay takes 500 ms, and the Uno's hardware PWM comes out at 490 Hz, because the cores carry the datasheet cycle counts. The live collaboration puts you and one student in the same circuit on Free. Pro holds five people, and Teacher and a school’s plan hold the whole room. A link a student shares back always covers reviewing the work. ## Lesson plans, one page a week Every week has a one-page PDF lesson plan you can download, print or hand to a substitute, alongside everything below that a plan needs. ### What is on the page, and on the PDF The objectives, the circuit, the exercise and the assessment for every week are on this page today, and each week's "Download the lesson plan (PDF)" button turns the same content into a one-page sheet ready to copy into whatever template your department already uses. - The week, the topic and the objectives, in the words above - A link to the circuit, already wired, that opens in one click with nothing to install - The exercise, timed for a double period, with the numbers a student should get - The assessment idea and a grading note - The parts list and a picture of the circuit, for printing without the machine open Also free: All 24 lesson plans, the start-tomorrow guide and the standards map · High school engineering and CTE: digital electronics · Middle school STEM: first circuits · Intro and AP physics: circuits ## Where this fits your standards This course has not been mapped against a published standard, and nothing here claims a code. What follows is the strands it genuinely touches, in the words the frameworks use, so you can do the mapping in the document your department already keeps. Engineering design and iteration Every week is define, build, test, change, test again, which is the design cycle those frameworks describe. Here that loop takes minutes rather than a week. Systems: inputs, processes, outputs Buttons and switches in, a chip or a program in the middle, LEDs, a display or a buzzer out. Weeks three, eight, ten and twelve are that sentence made physical. Computational thinking and programming Sequence, selection, iteration, variables and functions, written in C++ against a real chip rather than in a sandbox. Weeks two, three, and eight to twelve. Digital logic and number systems Truth tables, Boolean expressions, binary arithmetic, memory elements and counters, on real 74HC chips with supply pins and propagation delay. Weeks five to eight. Measurement, data and evidence Predicted against measured frequency, press counts against counted edges, twenty timed reactions with a mean and a range. Weeks one, three, four and ten submit numbers. Safe and correct practice Current limiting, supply pins, pull-ups and pull-downs, and a shared ground between two boards. Every one of those habits carries straight over to a real bench. If your department works to a particular framework, send us the unit and we will tell you which weeks cover it and which do not. We would rather say "that one is not covered" than print a code nobody has checked. ## Questions Do I have to teach it in this order? No. Weeks one and four to seven need no microcontroller at all, so a course that starts with digital logic can run five, six, seven, then two. The only hard dependencies are that the shift register week wants a board, and the project week wants everything before it. How long is a week meant to be? One double period, or one lecture and one lab. Each week is a circuit to open, an exercise that fits a sitting, and something to submit. A shorter lesson can drop the exercise and keep the circuit. A longer one takes the next week's circuit early. Do students need to buy anything? No. There is no kit, no board and no parts bin, and the free plan is the whole simulator with no time limit and no account needed to use it. Does the code they write here work on a real board? Code for the Uno and ESP32-C3 peripherals Mokxi models can move to those boards. The real memory maps and register offsets support that, and the final build still needs a test on physical hardware. Are there printable lesson plans? Yes. Every week has a "Download the lesson plan (PDF)" button: one page with the objective, the parts list, the steps, a picture of the circuit, and the assessment idea, ready to print or hand to a substitute. Can I change the circuits? Every circuit on this page opens in the editor as it appears. Change it, save it and share your version as a link. The class then opens your circuit instead of ours. What is not in the course? Anything Mokxi does not simulate honestly. No radio, no motor driver and no sensor library, and no op-amp design that turns on the part rather than the feedback network: a transistor now carries its junction capacitance, so a common-emitter stage has a real high-frequency corner and the Miller effect to design around, but the op-amp is still a rail-limited linear source with flat gain to any frequency, so an active filter’s rolloff here is the passive network’s alone. We would rather leave a topic out than teach it on a model that cannot carry it. Can students work on a Chromebook or a phone? Yes. It is a web page, the simulation runs on the machine in front of them, and the editor uses pointer events, targets big enough to hit and a layout that stacks on a narrow screen. ## Next Try it yourself first Open the editor with no account and build week one in five minutes. Open the editor What a class costs The Teacher plan is $129 a year for up to 40 students. A whole school gets a written quote. Seat calculator Teaching with it The devices, the IT questions and what you can teach today. For teachers Send it to a student The same page, written for the person doing the coursework. For students