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Synthesizing Robot Sounds

Kit photo needed

We don't have a photo of the assembled kit yet. The image below shows a key part.

Key part: XPT8871 amplifier board

Key part: XPT8871 amplifier board

Makes R2-D2-style robot sounds from a single GPIO pin by switching it on and off at different speeds, with no audio chip and no stored recordings.

Source book: STEM Robots
Kit page: https://dmccreary.github.io/stem-robots/kits/synth-sounds/
Printable one-pager: synth-sounds-one-pager.html

Features

  • Lab: Lab 1: Build the Sound Circuit
  • Lab: Lab 2: Sliding Pitches
  • Lab: Lab 3: Shaping the Volume
  • Lab: Lab 4: Sounds From Measurements
  • Lab: Lab 5: Add the Button
  • Lab: Lab 6: The Sound Jukebox

Benefits

  • Free, open lessons: the STEM Robots textbook has the kit page, wiring, and MicroPython code.
  • Ready-made curriculum: 6 additional lab pages walk students through the build step by step.
  • Budget: about $3 for a small 8 ohm speaker on eBay, added to a robot.

Parts

  • Raspberry Pi Pico ($4) — Microcontroller
  • Cytron Maker Pi RP2040 — Microcontroller
  • 10K Potentiometer — Input knob
  • MAX98357A I2S Amplifier ($0.99) — Audio amplifier
  • Momentary Push Buttons — Input button / switch
  • Piezo Buzzer / Speaker — Sound output
  • 830-Point Breadboard ($1.10) — Breadboard
  • Micro-USB Data Cable ($2.50) — Power and programming cable