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Chapter 0 wrap-up

Before you start

Closing thought

Every section in this chapter was about naming things precisely. A microcontroller is not a small laptop, and firmware is not an app. An ESP32 project means nothing until the chip is named. A capacitor's 104 is not 104 of anything. A register's 0xB2 is eight separate switches, and "compiled for this board" is a narrower claim than "works". Getting the words and numbers exact is most of what stands between a beginner and a datasheet.

So you can now read a listing for an ESP32-S3-WROOM-1 dev kit and know which part is the chip and which is the module. You can turn 0.1 μF into 100 nF, and 0x3C into 0011 1100. And you know to unplug the USB cable before moving a jumper. Chapter 1 puts those words to work on real hardware: what is on a development board, how to choose one, and how to buy a starter kit without paying for the wrong parts.

Recipes in this chapter

Step-by-step procedures for the problem types this chapter teaches.

Convert between SI prefixes Units, prefixes and scientific notation Check a circuit before you power it A safe workspace

Chapter review

One practice set per topic this chapter taught — same fixed, ungraded ladders as the practice panels inside each section.

Practice: Review: embedded systems (3 problems · doesn’t affect your progress)

What runs the moment a microcontroller gets power?

Correct! 🎉 Not quite.

Right on try — credit. Right — the answer had already been shown, so no credit this time. Next try is worth Answer shown after three tries — this one no longer earns credit. You chose to see the answer — this one earns no credit.

There usually is no operating system.

Apps belong to full computers.

The program is already stored in flash.

Why

Firmware is stored in flash and starts at power-on.

The firmware in its flash

A games console runs many games and updates apps over the internet. What is its main processor?

Correct! 🎉 Not quite.

Right on try — credit. Right — the answer had already been shown, so no credit this time. Next try is worth Answer shown after three tries — this one no longer earns credit. You chose to see the answer — this one earns no credit.

Many programs and an operating system point to a full computer.

Firmware is a program, not a processor.

A breakout board carries a part such as a sensor.

Why

Running and swapping many programs under an operating system is a full computer's job.

Running many programs and installing updates needs an operating system. What kind of processor runs one?

A microprocessor in a full computer

Which layer of the stack does this course leave to the later iot course?

Correct! 🎉 Not quite.

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Firmware is the heart of this course.

Hardware is built here from Chapter 2.

Hardware and firmware are covered in depth here.

Why

This course builds hardware and firmware; the cloud starts the iot course.

Which layer of the stack is the starting point of the later iot course?

Cloud

Practice: Review: Arduino, ESP32 and friends (3 problems · doesn’t affect your progress)

Which is a development board?

Correct! 🎉 Not quite.

Right on try — credit. Right — the answer had already been shown, so no credit this time. Next try is worth Answer shown after three tries — this one no longer earns credit. You chose to see the answer — this one earns no credit.

That is a chip.

That is a module.

That is the family.

Why

The DevKitC-1 carries a WROOM-1 module plus USB, a regulator, buttons and headers.

ESP32-S3-DevKitC-1

Which chip has an IEEE 802.15.4 radio for Thread and Zigbee, alongside Wi-Fi 6?

Correct! 🎉 Not quite.

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The S2 has Wi-Fi only.

The S3 has Wi-Fi and Bluetooth LE, no 802.15.4.

The RA4M1 has no radio.

Why

The ESP32-C6 has Wi-Fi 6, Bluetooth LE and 802.15.4.

Thread and Zigbee use an 802.15.4 radio. Check which chip's datasheet lists one.

ESP32-C6

Which chip is on the Raspberry Pi Pico 2?

Correct! 🎉 Not quite.

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The ESP32-S3 is Espressif's chip, on the DevKitC-1.

The RA4M1 is on the Uno R4 Minima.

STM32 chips are on ST's Nucleo boards.

Why

The Pico 2 is built on Raspberry Pi's RP2350.

Raspberry Pi designs its own microcontroller for the Pico boards. Which of these names is theirs?

RP2350

Practice: Review: units and markings (3 problems · doesn’t affect your progress)

A bag in your drawer is labelled 10 kΩ. How many ohms (Ω) is each resistor in it?

Correct! 🎉 Not quite.

Right on try — credit. Right — the answer had already been shown, so no credit this time. Next try is worth Answer shown after three tries — this one no longer earns credit. You chose to see the answer — this one earns no credit.

Why

× 1000: 10 000 Ω.

Correct answer

Also accepted:

Why

10000

A sleeping sensor draws 250 μA. Express that current in milliamps (mA).

Correct! 🎉 Not quite.

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Why

Up one rung: ÷ 1000. 250 μA = 0.25 mA.

Correct answer

Also accepted:

Why

Micro to milli is one rung up the ladder. Multiply or divide by 1000?

0.25

What value is a capacitor marked 224?

Correct! 🎉 Not quite.

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The last digit counts zeros: 22 then four zeros.

22 nF would be code 223.

Read it as 22 followed by four zeros, in pF.

Why

22 followed by four zeros: 220 000 pF = 220 nF.

Two digits, then a count of zeros, gives picofarads. Then move up a rung to nF.

220 nF

Practice: Review: binary, hex and registers (3 problems · doesn’t affect your progress)

What whole number is 0101 0101?

Correct! 🎉 Not quite.

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Why

64 + 16 + 4 + 1 = 85.

Correct answer

Also accepted:

Why

85

Turn the byte 1110 0001 into a two-digit hex value, written with 0x in front.

Correct! 🎉 Not quite.

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Why

1110 = E, 0001 = 1: 0xE1.

Correct answer

Also accepted:

Why

Split the byte into two nibbles. Each nibble becomes one hex digit.

0xE1

In the invented register, which value turns ENABLE on with MODE = 000 and SPEED = 00?

Correct! 🎉 Not quite.

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0x01 sets bit 0, which is part of SPEED.

0x08 sets bit 3, an unused bit.

0xFF sets every field.

Why

Only bit 7 set: 1000 0000 = 0x80.

Which single bit is ENABLE?

With only that bit set, write the byte and convert it to hex.

0x80

Practice: Review: a safe workspace (3 problems · doesn’t affect your progress)

Where does the soldering iron go whenever it is not in your hand?

Correct! 🎉 Not quite.

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A loose hot iron rolls and burns things, including you.

The board would scorch.

A hot iron in a drawer is a fire risk.

Why

The tip is hundreds of degrees hot; it lives in its stand.

In its stand

At low voltage, what is the main danger of a short circuit?

Correct! 🎉 Not quite.

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Skin keeps low-voltage current too small to feel.

That isn't the hazard here.

A shorted battery can burn or start a fire.

Why

A short lets a large current flow, and that current makes heat.

A short lets a large current flow. What does a large current do to wires and parts?

Heat

Which step of the power-up check catches a jumper running straight from 5V to GND?

Correct! 🎉 Not quite.

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Unplugging prevents a short while wiring but doesn't find one.

The voltage can be right and the wiring still shorted.

Watching catches it only after power is applied, which is too late to prevent it.

Why

Tracing supply to ground finds a path with no part in it before any power flows.

A jumper from 5V straight to GND is a path with no part in it. Which step follows paths before power flows?

Trace each wire from supply pin to ground

Practice: Review: using the course (3 problems · doesn’t affect your progress)

Which label is the strongest claim?

Correct! 🎉 Not quite.

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Compiling proves valid code, not behaviour.

Host tests prove the logic, not the wiring.

Each proves a different, narrower thing.

Why

Only a hardware test covers wiring, timing and real parts.

Hardware-tested

Whose account do you use for a free simulator such as Wokwi?

Correct! 🎉 Not quite.

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The course has no account of its own.

No page runs a simulator.

Boards don't have accounts.

Why

Simulators are optional links you open yourself, on your own account where one is needed.

Does the course host, or pay for, any outside service such as a simulator?

Your own, if one is needed; it's optional

Which route reads Chapters 9, 13 to 15 and 20 to 22?

Correct! 🎉 Not quite.

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The beginner route starts at Chapter 0.

That route starts at Chapter 0 too.

Low-power reads 4, 6, 20, 22 and 23.

Why

Embedded C/C++ is the short route for readers who already know electronics and C.

Which route is the short one for readers who already know electronics and C?

Embedded C/C++

Take the chapter quiz On to Chapter 1 →
← How to use this course Choosing and buying your kit →
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