Sound Output Methods

About This Infographic

Compares four ways to make sound with a microcontroller: the passive buzzer, the active buzzer, a small speaker driven by PWM, and an I2S DAC with amplifier. Click each column to see how the sound is generated, the wiring, the MicroPython code, and the cost, then use Quiz Me to test which output method fits a given task.

Image Prompt

Prompt

Please generate a wide-landscape infographic.

Render all text exactly verbatim. Do not substitute any numbers, paraphrase labels, or invent extra rows/columns/stats. Where a cell says "None" or "N/A", render that exactly.

A clean, modern, flat-design educational comparison infographic poster, landscape 16:9, titled at the top in large bold sans-serif: "Sound Output Methods Compared", subtitle beneath: "Passive Buzzer · Active Buzzer · Speaker + PWM · I2S DAC + Amplifier."

Layout: a four-column comparison table on a light off-white background (#F7F9FC). Each column is a rounded-corner card with a distinct accent color on its top edge and a component illustration at the top. A vertical row-label strip on the far left lists the nine attributes. Generous white space, thin divider lines, friendly textbook feel.

Column 1 (teal blue #1389A6): Header "Passive Buzzer"; Illustration: small black disc-shaped buzzer, two pins, no marking (passive type has two equal-length pins). Rows: · Sound generation: Membrane vibrates at the PWM frequency you set · Frequency range: ~20 Hz – 20 kHz (audible range); typical use 100 Hz – 10 kHz · Volume: Low — approx. 60–70 dB at 10 cm · Tone capability: Full melody — any note frequency is possible · Wiring: Signal pin → buzzer → GND (2 connections total) · Power: Driven directly from 3.3 V GPIO PWM pin · MicroPython: pwm = PWM(pin); pwm.freq(440); pwm.duty_u16(32768) for middle A · Typical cost: $0.20–$0.50 · Best for: Melodies, alerts, game sound effects, Morse code

Column 2 (warm orange #E07B39): Header "Active Buzzer"; Illustration: small black disc-shaped buzzer with a white sticker on top marked "+" (active type); two pins of different lengths (longer = positive). Rows: · Sound generation: Internal oscillator circuit generates a fixed frequency tone · Frequency range: Fixed internal tone — typically ~2 kHz (varies by component) · Volume: Medium–loud — approx. 70–85 dB at 10 cm · Tone capability: On/off only — single fixed beep tone · Wiring: VCC (5 V) → buzzer + pin; buzzer − pin → GND (or switch with transistor) · Power: 5 V recommended (louder than at 3.3 V); uses ~30 mA · MicroPython: Pin(n, Pin.OUT).value(1) to beep; value(0) to stop · Typical cost: $0.20–$0.50 · Best for: Simple alarms, button-press confirmation beeps, low-code audio feedback

Column 3 (deep purple #6A3FB5): Header "Small Speaker + PWM"; Illustration: small round 8 Ω speaker (36 mm diameter) with two wire leads; waveform symbol beside it. Rows: · Sound generation: Voice coil moves cone — driven by PWM square wave from GPIO · Frequency range: 20 Hz – 20 kHz (wider range and better fidelity than a buzzer) · Volume: Very low without an amplifier — needs transistor or op-amp circuit for useful volume · Tone capability: Full melody with better tonal quality than passive buzzer · Wiring: GPIO → transistor base → speaker; collector to V+; emitter to GND (or use amp) · Power: GPIO PWM signal through NPN transistor (2N2222) or small amp IC · MicroPython: PWM(pin) — vary freq() for notes; can play simple tunes · Typical cost: $0.50–$2.00 speaker + ~$0.10 transistor · Best for: Better-sounding tones; adding volume with a small amplifier IC

Column 4 (raspberry red #C7164E): Header "I2S DAC + Amplifier"; Illustration: small green MAX98357A breakout board with I2S pins labeled (BCLK, LRCLK, DIN) and a speaker connector. Rows: · Sound generation: Digital audio stream decoded by DAC, amplified to speaker · Frequency range: 20 Hz – 20 kHz (full audio bandwidth); 24-bit depth at up to 96 kHz sample rate · Volume: Loud — MAX98357A outputs up to 3.2 W into 4 Ω speaker · Tone capability: Full digital audio — WAV, PCM; tone synthesis, voice output · Wiring: 3 I2S bus pins (BCLK, LRCLK, DIN) + 5 V power + speaker · Power: 5 V supply to I2S amp module; I2S signal at 3.3 V · MicroPython: machine.I2S(id, sck, ws, sd, mode=I2S.TX, bits=16, format=I2S.STEREO, rate=44100, ibuf=20000) · Typical cost: $3–$8 for MAX98357A breakout module + speaker · Best for: Music playback, voice output, high-quality audio in advanced projects

Typography: one clean geometric sans-serif (Inter/Roboto style), bold column headers, monospace for MicroPython snippets, numbers bold. Footer bar: "Sources: Maxim MAX98357A datasheet · RP2040 I2S documentation (Raspberry Pi Ltd) — verified June 2026." Overall: tidy vector flat-design infographic poster, four-column grid with component illustrations, suitable for a textbook or classroom screen.