Hardware & targets

Firmware targets

Target	Board	Notes
host	any computer	simulation, tests, demo
rpi3	Raspberry Pi 3 B / B+	reference target, HiFiBerry Amp2
rpi0	Raspberry Pi Zero W	ARMv6, 1 core, 512 MB; USB-gadget first access

make firmware                 # rpi3
make firmware-rpi0            # Pi Zero W

Wiring

Step-by-step diagrams:

• Current setup, Raspberry Pi 3: amplifier, ESP32 light strip, LoRa button.
• Raspberry Pi Zero W: InnoMaker amplifier.
• Wi-Fi bedside button: ESP32 / Heltec, optional external button.
• Future board bench (not the current build): ESP32-S3 + ESP32, amplifier, LoRa and status LED on a breadboard.

Amplifiers

Board	Amplifier	Overlay
Pi 3	HiFiBerry Amp2 (PCM512x + TAS5756)	hifiberry-dacplus
Pi Zero W	InnoMaker HiFi AMP Pro Mini HAT (Infineon MA12070P)	merus-amp

The audio driver finds the card automatically (alsa_device: "auto") and sets the volume through the card’s own mixer control (Digital on the HiFiBerry, A.Mstr Vol on the MA12070P).

Caution

The Linux driver of the MA12070P accepts sample rates up to 48 kHz only. The stock merus-amp overlay claims GPIO 14/15 (enable, mute), which are the ESP32 UART pins: the rpi0 firmware loads merus-amp-uart, a variant without them. That is only valid if the HAT does not depend on those pins: do the continuity check in the Pi Zero W wiring guide. The SX1276 LoRa radio (SPI CE0 on GPIO 8) cannot be used on a Zero with this HAT.

Light

A 60-LED WS2812B strip driven by an ESP32 co-processor over UART (Pi GPIO 14/15, mini UART). Programs: dawn, sunset, evening breathing, reading light, ambience. See guided breathing.

Bedside remote

A LoRa (SX1276, 868 MHz) button dismisses the alarm physically. See the remote button note.

Bed vibration (planned)

A DIY tactile channel for breathing, music and progressive waking, coupled to the rigid frame of a slatted bed. Specified, not yet implemented — see the specification and the design note.

Not in the product

Camera, infrared illumination and bed-presence detection were removed on 2026-09-06. Nothing observes the sleeper.