Day 10: (Mon Sep 28, Week 6) Hobby Servos; Switch Circuits

Notes for 2026-09-28.

Assignments

New assignment, due Mon Oct 5: design a small device which uses one or two hobby servos and one or two switches for mechanical feedback. The detailed writeup is TBA. An example might be a single automatic fidget device which rolls a marble back and forth, use the switch to detect the ball state. The hobby servo output spline shaft should be decoupled from the device loads, e.g. it should connect using a wire link.

Agenda

1. Review results of Exercise: Pico Music. Please remember to submit documentation to Assignment 5 Shared Folder.

2. Discuss next assignment.

3. Introduction to hobby servos.

   • Hobby Servos (lab parts)

   • Hobby Servos (theory and practice)

   • Hobby Servo Mounting (hole patterns)

   • Hobby Servo Examples - Raspberry Pi Pico (programming)

4. Introduction to basic switch circuits.

   • Sensors and Switches (lab parts)

   • Resistors (lab parts)

   • Voltage Dividers (theory)

   • Digital Input/Output Examples - Raspberry Pi Pico (programming)

   • Sensor Circuits (circuit examples)

5. Specific parts

   • Lab Part 1896 (small servo)

   • Lab Part 0350 (lever)

   • Lab Part 0272 (ball tilt)

   • Lab Part 0355 (pushbutton)

   • Lab Part 0237 (photoreflective)

6. Related examples

   • Exercise: Actuated Marble Run Tile

   • Exercise: Reactive Marble Run Tile