Raspberry Pi computers have long been the darlings of the maker community. With their small, portable form factor and low cost, they’re a great tool for teaching kids—or anyone, really—how to program. The single-board computers run Linux and are powered by a USB phone charger. Plug in a mouse and keyboard, connect to a monitor or display, and you’re ready to go where your imagination takes you.
It's fun to see all of the creative projects that programmers of all skill levels have shared on the Raspberry Pi website. There are home security systems, digital cameras, and, for you Star Trek fans, even tricorders. But the applications that really sparked my interest were the audio-related ones, since Maxim has a great new audio amplifier on the market, the MAX98357. The MAX98357 is a digital pulse-code modulation (PCM) input Class D power amplifier that provides Class AB audio performance with Class D efficiency. Diving deeper on the Raspberry Pi website, I found the Music Projects page with details on how to create everything from a GPIO music box to a doorbell chime, special effects for a movie or game, and a drum loop.
Whether you want to create a retro radio like the one pictured here or another electronic device with high-quality audio, the MAX98357 audio amplifier provides Class AB audio performance with Class D efficiency.
What makes Raspberry Pi and MAX98357 a great pair? They’ll work together nicely in a variety of audio applications. Adafruit, which is selling a breakout board featuring the MAX98357, offers this testimony on its website: “Listen to this good news - we now have an all in one digital audio amp breakout board that works incredibly well with the Raspberry Pi! If you're looking for an easy and low cost way to get your digital sound files bumpin' then the MAX98357 I2S Amp Breakout is for you. It takes standard I2S digital audio input and, not only decodes it into analog, but also amplifies it directly into a speaker. Perfect for adding compact amplified sound, it takes 2 breakouts (I2S DAC + Amp) and combines them into one.”
In fact, Adafruit sells a few other boards that pair a Raspberry Pi computer with the MAX98357. The Pimoroni pHAT BEAT for Raspberry Pi Zero can be used to create a small desktop radio, to stream music from a smartphone, or develop a standalone streaming music player. Build your own "pirate radio" with Pimoroni's Pirate Radio Kit, which features the pHAT BEAT DAC and stereo amp and the MAX98357A. One enterprising engineer shared a photo of a $20 WiFi speaker created using Raspberry Pi Zero and MAX98357.
What will you create with MAX98357?
Additional MAX98357 Resources
Document: Designing Better, Simpler Audio Solutions with Dynamic Range Enhancement (DRE)
Blog: Why Your Audio DAC or Digital Amp Should Spec Dynamic Range Instead of SNR