What SquarePi Is and Why You’d Build One
SquarePi is a Raspberry Pi audio amp project that combines a Pi-compatible HAT, a 15-band hardware equalizer, and local browser control to create a cloud-free DIY hi-fi amplifier you can run entirely on your own network without accounts or subscriptions.
SquarePi is built around a Raspberry Pi HAT that uses the TAS5805M Class-D amplifier to deliver stereo output while handling equalization in hardware. Instead of pushing EQ work to the CPU, the chip offers 15 bands of biquad filtering controlled over I²C, so the Raspberry Pi writes filter coefficients while the audio path stays inside the amplifier. This makes it attractive if you care about low latency and keeping CPU load near zero. The goal is straightforward: power the system and have it appear on your network without any app, user account, or subscription requirement. This fits privacy-conscious builders who want an offline smart speaker or room amp that keeps working the same way no matter what happens to cloud services or vendor firmware updates.
Once set up, SquarePi acts as a flexible Raspberry Pi audio amp with Bluetooth, DLNA, Spotify Connect, and AirPlay available from a single one-command software install. All control happens through standard web interfaces accessible in a browser rather than through proprietary applications or cloud dashboards. That browser-based approach means you can manage playback, sources, and equalizer settings from phones, laptops, or tablets on your LAN, with no external dependency.
What You Need Before You Start
Before you follow any how-to steps, it helps to be realistic about parts and software. You will need a Raspberry Pi with a 40-pin header and a compatible HAT slot, plus the SquarePi HAT itself. The HAT uses a standard 65×61 mm Raspberry Pi 40-pin form factor so it plugs directly onto the Pi’s header. You can either assemble the HAT from components or use a pre-assembled board.
On the software side, SquarePi requires Raspberry Pi OS Lite based on Bookworm (Debian 12) or Trixie (Debian 13). You should avoid the Desktop image because it installs PulseAudio, which conflicts with the ALSA configuration SquarePi relies on. You also need an SD card for the operating system; Pi-based handheld projects such as RootBoard use the same approach of supplying a Pi Zero or Zero 2 W plus a memory card for the OS. Network access is important too, because the install is triggered through a single shell command run over SSH.
For power, the SquarePi HAT accepts 12–24 V DC via a barrel jack and can power the Pi from that same input. The board breaks out each audio channel on a 2‑pin terminal block so that you can connect any passive speakers, which makes it ideal if you are turning existing bookshelf speakers into a networked, offline smart system. You will need suitable speakers and wiring, along with a safe DC power supply in the supported voltage range.
Step-by-Step: Build and Configure Your Cloud-Free Amp
You only have one ordered sequence to worry about for the core build: assemble the hardware, flash the right OS image, run the installer, and reboot. The key is to follow the order exactly so the software lands on a known-good base system and the HAT is present when drivers and services are configured. Skipping the OS requirement or changing the step order tends to cause small, annoying issues later, especially around audio routing and equalizer control.
- Solder the SquarePi HAT components, or use a pre-assembled board if you have one.
- Mount the HAT onto the Raspberry Pi’s 40-pin header so it sits like any other open source HAT-compatible board.
- Flash Raspberry Pi OS Lite (Bookworm or Trixie) to an SD card; don’t use the Desktop image because it installs PulseAudio, which conflicts with ALSA.
- Insert the SD card, power the Pi from a 12–24 V DC supply through the HAT’s barrel jack, boot, and connect via SSH.
- Run the provided install command, for example `sudo bash install.sh`, selecting optional flags like `--with-dlna` or `--with-airplay` if you want those features.
- Reboot the Raspberry Pi when the script finishes; after restart, the device should respond on your network as squarepi.local.
According to the project documentation, “Reboot. The Pi is now reachable at squarepi.local.” After that point, the system behaves like other DIY Raspberry Pi audio amp setups: it boots, joins your network, and waits for streaming sources. Because the hardware equalizer lives entirely on the TAS5805M chip, the Pi never touches audio data for EQ and CPU usage remains low. The important caveat is to keep your base OS clean; extra sound servers or non-Lite images can interfere with how the installer configures ALSA and the hardware DSP pipeline.
Control Everything From Your Browser
Once the install finishes and the Pi reboots, you get a few predictable ways to control your new DIY hi-fi amplifier over the network. First, the host name squarepi.local gives you a myMPD-based control interface where you can manage playback, browse your music library, and work with Bluetooth, DLNA, and AirPlay sources in one place. This keeps the user experience within your browser instead of relying on separate proprietary apps.
Second, the dedicated DSP panel at squarepi.local:8081 exposes the 15-band hardware equalizer with a live frequency-response graph, EQ presets, and A/B comparison. Thirteen presets such as Flat, Bass Boost, Treble, Night Mode, Rock, and Classical come pre-installed, and you can manually adjust each band between 20 Hz and 16 kHz by up to ±15 dB. Custom curves are written to the amplifier chip, so they survive power cycles. Bluetooth runs in parallel: the Pi is always discoverable, pairs without a PIN, and can show now-playing metadata from your phone when available.
All sources share the same hardware signal chain: audio is upscaled to 48 kHz/24-bit to benefit from the Pi’s more accurate PLL at that rate, then resampled with SoXR when needed, mixed with ALSA’s dmix layer, and finally equalized inside the TAS5805M before driving your speakers. This means Bluetooth, DLNA, Spotify Connect, AirPlay, USB drives, and internet radio can all be active together without one pausing another. From a privacy standpoint, the browser-based layer and local networking keep control within your own infrastructure while the HAT design avoids any external cloud dependency or subscription.
Is SquarePi Worth Building?
SquarePi is aimed at people who want a reliable, offline smart speaker or room amp that behaves like consumer wireless audio gear without the cloud baggage. The design gives you a Raspberry Pi audio amp with 2×30 W stereo Class‑D output at 4 ohms and 24 V, plus a signal path tuned for 48 kHz/24‑bit playback. The total parts cost for the board is under USD 30 (approx. RM140), which keeps the core hardware easily within DIY reach.
Commercial wireless speakers can cost USD 150–500 (approx. RM690–RM2,300) and often require accounts or cloud tie-ins that can change or disappear with firmware updates. Here, you get a HAT designed to integrate directly with the Pi’s 40‑pin header, a hardware equalizer controlled in real time, and browser-based control interfaces instead of proprietary tools. If you are comfortable flashing Raspberry Pi OS Lite and running a shell script, the build is straightforward, and the reward is a DIY hi-fi amplifier that stays under your control and continues to work even if vendors and services come and go.
