Apollo CAST-1 Smart Audio Streamer | Make Active Speakers Smart with SendSpin

Apollo CAST-1 Audio Casting Device: Transform Any Speaker into a Smart ESPHome StreamerDo you have high-quality active speakers, a soundbar, or a classic amplifier that sounds too good to replace, but you miss modern smart home functionalities? With the Apollo CAST-1 from Apollo Automation, you can smarten up any audio setup in an instant. This compact casting device runs on open-source ESPHome firmware and operates 100% locally without relying on external cloud servers. Connect the CAST-1 to your equipment via the 3.5mm jack output and link it directly to your central smart home for streaming audio, automated voice notifications, and alarm signals.Multiroom Audio Synchronization via SendSpin & Music AssistantThe Apollo CAST-1 comes factory-equipped with support for SendSpin: the advanced, open audio-streaming protocol developed by the Open Home Foundation. In combination with Music Assistant, SendSpin enables multiple CAST-1 units or a mix of different smart speakers to work together in perfect synchronization. Seamlessly walk from the kitchen to the living room while your favorite playlist continues to play in sync, or send a spoken notification to specific areas as soon as a sensor detects motion.Audiophile 32-Bit DAC, Bluetooth Proxy & Expansion CapabilitiesDespite its extremely compact size of only 45 x 45 x 15 mm, the CAST-1 delivers unparalleled sound quality thanks to the high-quality Texas Instruments PCM5122 32-bit DAC (112 dB SNR / 2.1 VRMS). Under the hood is a powerful ESP32-S3 microcontroller (16 MB Flash, 8 MB PSRAM). In addition to audio streaming, the CAST-1 also functions as an active Bluetooth Proxy for your smart home network, significantly extending the range of your BLE sensors. Furthermore, solder pads are present for GPIO pins, allowing you to easily connect an addressable RGB LED strip (such as WS2812) for dynamic visual light effects to the beat of your music.Ecosystems & Compatibility Home Assistant: Fully local and automatically discoverable via mDNS and the ESPHome integration within Home Assistant. Works seamlessly with Music Assistant and directly serves as a BLE Bluetooth Proxy. Homey Pro: Easy to connect by adding the CAST-1 to your network and controlling it via Home Assistant Flows, DLNA/UPnP, or ESPHome community integrations within Homey Pro. SmartThings: Integration possible via the Home Assistant bridge or via local HTTP webhooks and ESPHome media player commands. Pro-Tip from slimhuisje.nl: Use the Apollo CAST-1 behind your amplifier not only for music, but also link it in Home Assistant to your doorbell or security sensors. When someone rings the doorbell, have a subtle chime play over your speakers and use the built-in RGB LED status indicator as a visual notifier!Functionalities & Physical Actions 100% Local Control: No cloud, subscription, or external servers required; maximum privacy and instant response. High-End Audio DAC: Texas Instruments PCM5122 (32-bit stereo, 112 dB SNR, -93 dB THD+N, 2.1 VRMS line out). SendSpin Protocol: Full integration with Music Assistant for synchronized multiroom audio. Bluetooth Proxy: Directly extends the range of your Bluetooth sensors and devices at home. Wi-Fi & Ethernet option: Operates by default on 2.4 GHz Wi-Fi and can optionally be expanded with an Ethernet HAT (W5500) for a wired network connection. Open-Source ESPHome Firmware: Easily customizable and expandable via the ESPHome add-on dashboard. GPIO Expansion Port: Solder pads (5V, GND, IO1) for connecting LED strips or external sensors. Extremely Compact: With dimensions of 45 x 45 x 15 mm, it can be effortlessly concealed behind audio equipment. Package contents and dimensions 1x Apollo CAST-1 Smart Audio Streaming Device 1x Quick Start Guide Product dimensions: 45 x 45 x 15 mm Please note: A USB-C power cable (5V/1A adapter) and a 3.5mm audio cable are not included as standard and must be purchased separately. For a wired network connection, the optional Apollo Ethernet HAT is required.Technical specifications Specification Value Brand Apollo Automation Model / SKU CAST-1 EAN 0850062536034 Microcontroller Espressif ESP32-S3 (16 MB Flash, 8 MB PSRAM) Digital-to-Analog Converter (DAC) Texas Instruments PCM5122 (32-bit stereo, 112 dB SNR, -93 dB THD+N) Firmware & Protocols ESPHome (Open-Source), SendSpin (Music Assistant native), ESPHome Media Player Network Connection Wi-Fi 2.4 GHz; Ethernet supported via optional Ethernet HAT (W5500) Bluetooth BLE, Home Assistant Bluetooth Proxy capable Audio Output 3.5mm analog line-out (2.1 VRMS full scale) Power Supply USB-C (5V / 1A) Expansion Ports Solder pads for 5V, GND, IO1 (suitable for addressable LED strips or sensors) Dimensions 45 x 45 x 15 mm Frequently Asked Questions (FAQ)How do I connect the Apollo CAST-1 to Home Assistant and Music Assistant?Once the Apollo CAST-1 is powered on and connected to your network, it will be automatically discovered in Home Assistant and Music Assistant via mDNS. You just need to click 'Add' within the integrations to start using the device immediately.Does the Apollo CAST-1 also work with a wired Ethernet connection?Yes, although the device comes standard with Wi-Fi 2.4 GHz, you can expand it with the optional Apollo Ethernet HAT (W5500) for an ultra-stable, wired network connection.Does the CAST-1 have a built-in battery or power adapter?No, the CAST-1 does not contain an internal battery. The device is continuously powered via a standard USB-C port (5V / 1A). You can use any USB-C power supply or a free USB port on your amplifier for this.What is the function of the built-in Bluetooth Proxy?The ESP32-S3 chip on the CAST-1 establishes itself as a Bluetooth receiver for Home Assistant. This allows BLE sensors (such as temperature, humidity, or presence sensors) located near the CAST-1 to be seamlessly picked up and forwarded to your central controller.Can I customize the functionality of the CAST-1 myself?Absolutely! Since the CAST-1 runs entirely on open-source ESPHome, you can easily modify the YAML configuration, add extra functions, or expand the hardware with your own sensors and LED strips via the ESPHome add-on in Home Assistant.✅ slimhuisje.nl | Your specialist in ESPHome, local audio streaming, and the ultimate Home Assistant experience!