UI-to-Hardware Interfacing

UI-to-Hardware Interfacing · Course page

Drive LEDs and read a button with gpio, build a touch-screen control panel that drives real lights, then read a knob and CapSense with filtering.

Module objectives

Write MicroPython that controls real hardware and can explain what happens at the electrical pin: a chasing light pattern, a debounced button, a touch control panel whose on-screen state matches the real lights, and a knob gauge and touch strip that show a raw value against a filtered one.

Lessons

Lesson	Topic	Time (min)	Slides
2.1	The gpio module: LEDs, a button and a board that describes itself	50	slides.md
2.2	Behind the LED and the button: active-low, debouncing, and a loop that never stops	55	slides.md
2.3	Hands-on: a chasing light and a button, then publish to the broker	75	slides.md
2.4	The touch screen and your first widget	50	slides.md
2.5	The event loop: touch the screen and a real light turns on	70	slides.md
2.6	Hands-on: our own touch control panel, and the next widget	65	slides.md
2.7	Analogue and touch: the ADC knob and CapSense	65	slides.md
2.8	Filtering a signal: EMA and Median, then walking through a gauge	65	slides.md
2.9	Hands-on: a knob gauge and a touch strip	70	slides.md

The lessons in this module come in sets of three: concept → code walk-through → hands-on (the third lesson of each set has practice files and solutions).

Module checkpoint

You pass this module when you can do every item below (the details are in the Lab section of the hands-on lessons):

• A chasing light pattern runs across every LED that gpio.num_leds() reports, its speed can be adjusted, and pressing the button ten times makes the counter show exactly ten
• You can explain what happens, and why, if the debounce code is removed
• A three-colour control panel: touching it on and off follows the real light, and the on-screen state matches the real light in every case tested
• Turning the knob moves the bar across its whole range, threshold lights turn on one at a time, and the filtered value visibly sits steadier than the raw value on screen
• You can answer how a low alpha and a high alpha for the EMA give different results