MAX98357A I2S Amplifier Kit

Replaces the robot's single-tone piezo beep with a class-D amplifier chip that drives a real speaker loud enough to fill a room on three AA batteries.

Source book: STEM Robots
Kit page: https://dmccreary.github.io/stem-robots/kits/max98357a-amp/
Printable one-pager: max98357a-amp-one-pager.html

Features

• Lab 1: Meet Your Kit - turn it on and try
• Lab 2: Your First Sound - connect to
• Lab 3: Press the Button - the R2D2 sound
• Lab 4: Light Up the Display - draw
• Lab 5: Turn the Dial - the potentiometer,
• Lab 6: Volume Control Lab - the full

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.
• Classroom friendly: built on a solderless breadboard or no-solder connectors.
• Instant feedback: students see their code's results on lights or a display.
• Budget: about \(11–\)15 (amplifier about \(8–\)12 on eBay, small 8 ohm speaker about $3).

Parts

• Cytron Maker Pi RP2040 ($10) — Controller board (built-in RP2040)
• 10K Potentiometer — Input knob
• 8 Ω 50 mm Speaker — Sound output
• TT DC Gear Motors — Motor / actuator
• GC9A01 Round TFT ($3.19) — Display
• MAX98357A I2S Amplifier ($0.99) — Audio amplifier
• Momentary Push Buttons — Input button / switch
• Piezo Buzzer / Speaker — Sound output
• SG90 Micro Servo — Motor / actuator
• 830-Point Breadboard ($1.10) — Breadboard
• Micro-USB Data Cable ($2.50) — Power and programming cable