Lesson 2 Pupil Notes
Title
LEDs, GPIO, And Blinking
Big Question
How can one pin on a microcontroller make a real light turn on and off?
What This Lesson Is About
GPIO pins let the board interact with the outside world. In this lesson we use an LED as our first visible output and learn why blinking is such an important embedded systems test.
Key Words
- GPIO
- output
- input
- LED
- timing
- PWM
Before You Start
- Make sure the board is connected and responding.
- Find the LED-related controls in the dashboard.
- Be ready to watch both the board and the log.
What To Remember
- GPIO means General Purpose Input/Output
- an output pin can drive a device such as an LED
- blinking proves that code is reaching the hardware
- timing matters as much as logic in embedded systems
- PWM is fast switching that can change average brightness
What We Did
- used LED controls from the dashboard
- watched the LED respond
- linked blink behaviour to GPIO and timing
- discussed how a digital signal can still create brightness effects
What To Look For
- does the LED react immediately?
- what is the difference between a steady output and a blink pattern?
- how does a change in timing change what people see?
Try This
- Use
HELLO_WORLD. - Use the toggle LED control.
- Compare a simple on/off action with a repeating blink pattern.
Why It Matters
This is the first strong link between software and electricity. A tiny change in program behaviour causes a visible change in the real world.
Check Yourself
- What does GPIO mean?
- Why is blinking often called embedded hello world?
- What is PWM trying to control?
- Why does timing matter for LEDs?
Reflection
- A blink pattern I noticed:
- Something that changed when timing changed:
- One real product that must control LEDs carefully: