r/homeassistant — Smart Home — 2026-08-28T20:42:38+00:00
Summary
Apollo Automation has announced the CAST-1, an open-source audio streaming device positioned as a successor to Google's Chromecast Audio, which was discontinued in 2019. The 45 x 45 x 15 mm puck features an ESP32-S3 with 16 MB flash and 8 MB PSRAM, a TI PCM5122 DAC (32-bit stereo with 112 dB SNR and 2.1 VRMS line output), USB-C power, and a 3.5mm audio output for connecting to powered speakers, amps, or receivers. It runs open-source ESPHome firmware and integrates natively with Home Assistant and Music Assistant, using Sendspin for sample-accurate multi-room synchronization, while also functioning as a standard ESPHome media player for TTS and alerts. The device operates entirely locally with no account or subscription required, supports 2.4 GHz Wi-Fi or an optional W5500 Ethernet HAT, Bluetooth proxy capability, and exposed solder pads for GPIO expansion such as LED strips that react to playback. The project's GitHub repository and documentation wiki are publicly available.
Massive thanks to the Open Home Foundation , the Music Assistant team, and everyone working on Sendspin . None of this exists without their work, and the sync quality is incredible. Please go use Music Assistant and Sendspin if you have not already! The Chromecast Audio has been discontinued since 2019, and a lot of us have been looking for the same thing ever since! A small puck with a 3.5mm out that syncs across rooms and keeps everything on your own network. Our CAST-1 plugs into powered speakers, an amp, a receiver, or desktop monitors. USB-C for power, 3.5mm for audio, and that is the whole install. Specs: DAC is a TI PCM5122. 32-bit stereo, 112 dB SNR and dynamic range, -93 dB THD+N, 2.1 VRMS line out. This is the part we most wanted to get right, since the converter decides what your speakers actually receive. ESP32-S3 , 16 MB flash, 8 MB PSRAM, running open source ESPHome . Sendspin for sample-accurate sync, native in Music Assistant. Also shows up as a standard ESPHome media player in Home Assistant for TTS, doorbell chimes, and alerts. Solder pads for 5 V, GND, and IO1. Audio and GPIO on the same board under the same ESPHome config, so an LED strip can react to playback without a second controller. Bluetooth proxy capable. Wi-Fi 2.4 GHz, or wired with the optional W5500 Ethernet HAT. 45 x 45 x 15 mm. mDNS discovery. 100% local, no account, no subscription. We run several units around the Apollo workshop on completely different speakers and they stay locked together. This finally let me get rid of all of my Google Home speakers! Please let us know if there are any questions! GitHub: https://github.com/ApolloAutomation/CAST-1 Wiki: https://wiki.apolloautomation.com/products/cast1/introduction/ submitted by /u/ApolloAutomation [link] [comments]
Original article: https://www.reddit.com/r/homeassistant/comments/1w12924/chromecast_audio_successor_esphome_based_esp32s3/ Source: r/homeassistant