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Electrical track
Test equipment

The multimeter, the oscilloscope and the logic analyzer, on real faults

Volts across and amps through, the power-off checks, PWM and bounce on a scope, a logic probe and analyzer, then one circuit with three bugs.

FreeIn your browser3 courses, 20 lessons, about 10 hours
Start freeThe multimeter: volts across, amps throughSee the course
Overview

How you will learn it

Test equipment is easy to learn badly: put the probes anywhere and hope. Engineers use a method instead, and each tool answers a different question. A meter says what the steady values are, a scope says how they change, and a logic analyzer says what was sent.

Debug like an engineer teaches each tool on a circuit with a real fault in it, then ends with one circuit hiding three bugs that you find with all of them. AC, signals and filters adds a full lesson on reading a scope.

Outcomes

What you will learn

  • Measure voltage across a part and current through it without damaging anything.
  • Do resistance, continuity and diode checks with the power off.
  • Read rise time, PWM and switch bounce on an oscilloscope.
  • Decode a bus on a logic analyzer and debug with Serial.
Your route

The courses and lessons to take

Every lesson opens in the editor right away, signed in or not, and the simulator checks each step.

  1. Step 1 路 6 lessons 路 2 h

    Debug like an engineer

    The whole course.

    1. The multimeter: volts across, amps throughTwo meters on one LED circuit: a voltmeter across the LED and an ammeter in the loop. Why one goes across and the other goes in line, and how to check Ohm's law against real readings.
    2. The power-off checks: ohms, continuity and diodesThree meters on a circuit with no supply at all: one reading a resistor, one beeping across a switch, one testing an LED. Why these checks need the power off, and what each one tells you.
    3. What a scope sees: PWM, rise time and a bouncing buttonA meter gives you one number; an oscilloscope gives you the shape. Measure a PWM pin's frequency and duty, watch an RC slow its edges down, and catch a button bouncing a dozen times in one press.
    4. Logic probe and logic analyzerA logic probe says high, low or nothing; a logic analyzer records the ones and zeros and decodes them into bytes. Find a floating pin, fix it with a pull-up, and read serial straight off the wire.
    5. Boss: one circuit, three bugsA button and an LED that do nothing, with three faults planted at once. Use the method engineers use (reproduce, isolate, measure, fix) and a meter to find all three.
    Every lesson in the course
  2. Step 2 路 7 lessons 路 4 h

    AC, signals and filters

    More on reading a scope, with sine waves and RMS.

    1. Reading a scopeThe waveform lab: an Uno makes sine, triangle, sawtooth and square waves with PWM and an RC filter. Volts per division, time per division, period and frequency, checked with a frequency counter.
    Every lesson in the course
  3. Step 3 路 7 lessons 路 4 h

    Talk to chips: I2C, SPI and UART

    A bus on the logic analyzer, byte by byte.

    1. See the bus on the logic analyzerClip a logic analyzer on SDA and SCL and read a real I2C transfer bit by bit: START, address, ACK, data, STOP. Then meet a bus that looks like I2C and is not.
    Every lesson in the course
Keep going

Guides and tools on the same subject

Track

Electrical track

Current and voltage you can see, then transistors, op-amps, filters, power and PCBs. Every circuit runs in a real circuit simulator in your browser.

See the whole track
Questions

Questions people ask

How do I measure current with a multimeter?

In series: break the circuit and put the meter in the gap, with its lead in the amps socket. Measuring current across a supply is the classic way to blow a meter fuse, and the lesson shows why.

Do I need an oscilloscope to learn electronics?

Not at first, but it is the tool that explains timing, PWM and noise. The simulator has one, so you can learn it before buying one.

What is a logic analyzer for?

Recording many digital lines at once and decoding what they carry, such as I2C, SPI or UART bytes. It is how you find out what a chip was actually sent.