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Day 3

Embedded Programming

Boards, the IDE, and your first working code.

Day 3

Introduction to Embedded Programming

From blank board to blinking LED

Arduino / ESP32 / STM32 boardsThe IDE and sketch structuresetup(), loop(), pinMode()Serial monitor for debuggingLED control & PWM fadingPotentiometer & analog inputData types, variables, operators

ElectroLab · Embedded Programming1 / 19

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Lesson notes

Pick a board, install the IDE, and learn the anatomy of a sketch: setup(), loop(), pins, the serial monitor, blinking and fading LEDs, reading a potentiometer, plus data types and operators.

Day 3

Introduction to Embedded Programming

From blank board to blinking LED

Arduino / ESP32 / STM32 boards
The IDE and sketch structure
setup(), loop(), pinMode()
Serial monitor for debugging
LED control & PWM fading
Potentiometer & analog input
Data types, variables, operators

Topic 1

Choosing a Board

Arduino vs ESP32 vs STM32

	Arduino Uno	ESP32	STM32
Core	ATmega328 · 8-bit	Dual 32-bit	ARM Cortex-M
Speed	16 MHz	240 MHz	72–480 MHz
Wireless	None	Wi-Fi + Bluetooth	None (varies)
Best for	Learning basics	IoT & connectivity	Performance & control

For this bootcamp we mostly use ESP32 — it has Wi-Fi/BT and is cheap, but Arduino code runs on all of them.

The boards you will program

Different brains, same idea — pins on the edges, USB to upload code.

Arduino Uno — classic 8-bit, beginner-friendly
ESP32 — fast, Wi-Fi + Bluetooth

Topic 2

The IDE & Sketch Structure

Two functions run every sketch

setup()

Runs ONCE at power-on/reset
Configure pins, start Serial
Initialize sensors and libraries

loop()

Runs FOREVER, over and over
Your main program logic
Read sensors → decide → act

Walk through: install IDE, select board, select port, click Upload. The classic flow.

pinMode + the skeleton

pinMode() tells a pin to be an INPUT or OUTPUT
Serial.begin() opens the USB link for debugging

void setup() {
  pinMode(13, OUTPUT);   // set pin 13 as an output
  Serial.begin(115200);  // start serial at 115200 baud
}

void loop() {
  // your code repeats here, forever
}

Topic 3

Serial Monitor — your debugger

Print values to see what is happening

Match the baud rate in the monitor to Serial.begin()
print() stays on the line; println() moves to the next

void setup() {
  Serial.begin(115200);
}

void loop() {
  int reading = analogRead(34);
  Serial.print("Sensor: ");
  Serial.println(reading);   // println adds a new line
  delay(500);
}

Teach "printf debugging" — when in doubt, print the variable. It is the #1 beginner debugging skill.

Topic 4

LED Control & PWM

Blink, then fade

digitalWrite = fully ON or OFF
analogWrite uses PWM — rapid on/off pulses fake an in-between brightness

// Blink
digitalWrite(13, HIGH);  delay(500);
digitalWrite(13, LOW);   delay(500);

// Fade with PWM (analogWrite: 0–255)
for (int b = 0; b <= 255; b++) {
  analogWrite(ledPin, b);   // brightness
  delay(5);
}

PWM = Pulse Width Modulation

The pin switches on/off thousands of times a second. The fraction of time it stays ON — the "duty cycle" — sets the average power.

25% duty = dim · 75% = bright
Same trick sets motor speed
analogWrite(pin, 0–255)

The bar shows average power tracking the duty cycle — the LED brightness follows it.

Topic 5

Analog Input — the potentiometer

Read a knob, control brightness

analogRead returns a number across the ADC range
map() rescales one range to another — incredibly useful

int raw = analogRead(34);          // 0–4095 on ESP32
int duty = map(raw, 0, 4095, 0, 255);
analogWrite(ledPin, duty);          // knob sets brightness

Digital vs Analog pins

Digital

Only HIGH or LOW (1 or 0)
digitalRead / digitalWrite
Buttons, LEDs, logic signals

Analog

A range of values (a voltage)
analogRead in, PWM out
Sensors, knobs, dimming

Topic 6

Data Types & Operators

Common data types

Type	Holds	Example
int	whole numbers	-5, 0, 42
float	decimals	3.14, 0.5
bool	true / false	true
char	one character	'A'
String	text	"hello"
byte	0–255 (8 bits)	0xFF

Variables, constants & operators

Storing values

int ledPin = 13; — a variable
#define PIN 13 — text replaced before compile
const int PIN = 13; — typed, safer constant

Operator families

Arithmetic: + − * / %
Relational: == != < > <= >=
Logical: && || !
Bitwise: & | ^ ~ << >>

Prefer const over #define in modern code — it is type-checked. Bitwise ops matter for registers and flags.

Day 4 — Key Takeaways

setup() runs once; loop() runs forever
pinMode sets direction; digitalWrite/Read for on-off
Serial.println is your debugger
PWM (analogWrite) fakes analog output for fading & speed
analogRead + map() turns a knob into any range
Choose the right data type; know your operator families