--- title: "How Does W5500 Bring Analog Audio into Sendspin on Apollo CAST PRO-1?" url: "https://maker.wiznet.io/Benjamin/resellers/how-does-w5500-bring-analog-audio-into-sendspin-on-apollo-cast-pro-1/" markdown_url: "https://maker.wiznet.io/Benjamin/resellers/how-does-w5500-bring-analog-audio-into-sendspin-on-apollo-cast-pro-1/md" type: "VAR: Value-Added Reseller Products" author: "Apollo Automation LLC" author_url: "https://apolloautomation.com/products/cast-pro-1" editor: "WIZnet" editor_url: "https://maker.wiznet.io/" original_author: "Apollo Automation LLC" original_url: "https://apolloautomation.com/products/cast-pro-1" published: "2026-11-09" language: "en" tags: ["W5500", "Home Assistant", "ESPHome"] hardware: ["WIZnet W5500"] likes: 0 views: 8 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # How Does W5500 Bring Analog Audio into Sendspin on Apollo CAST PRO-1? > Apollo CAST PRO-1 streams line-level audio to Music Assistant over built-in W5500 Ethernet, with optical output and Wi-Fi in one ESPHome device. Original author: Apollo Automation LLC (source: https://apolloautomation.com/products/cast-pro-1) ## Components - **WIZnet W5500** x 1: Built-in SPI Ethernet interface on Apollo CAST PRO-1; ESP32-S3 and ESPHome use the host lwIP network stack. ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500)) WIZnet parts: W5500 ([Datasheet](https://docs.wiznet.io/Product/Chip/Ethernet/W5500/datasheet?utm_source=maker&utm_medium=project&utm_campaign=w5500), [product hub](https://maker.wiznet.io/products/w5500/)) ## Documents and links - [Apollo CAST PRO-1 official shop and photos](https://apolloautomation.com/products/cast-pro-1) (code): Current product, original photos and purchase options. Base USD 68.99 with case; observed 9 November 2026. - [Apollo CAST PRO-1 launch and family comparison](https://apolloautomation.com/blogs/news/cast-pro-1-stream-record-player-every-room-music-assistant) (schematics): Vendor article dated 4 November 2026; input, optical output, built-in Ethernet and CAST-1 comparison. - [CAST PRO-1 firmware source](https://github.com/ApolloAutomation/CAST_PRO-1): ESPHome configuration, README, public workflows and CC BY-NC-SA 4.0 license. - [W5500 configuration and SPI pin map](https://github.com/ApolloAutomation/CAST_PRO-1/blob/main/Integrations/ESPHome/Core.yaml): W5500, 40 MHz SPI, network priority, Wi-Fi coexistence and audio routing. - [Line In capture and Sendspin source](https://github.com/ApolloAutomation/CAST_PRO-1/blob/main/Integrations/ESPHome/line_in.yaml): 48 kHz stereo capture, Opus/PCM selection and shared-I2S output constraint. - [CAST PRO-1 setup guide](https://wiki.apolloautomation.com/products/castpro1/setup/getting-started/): Ports, power, Music Assistant 2.10.7+, optical selection and playback-delay setting. - [Stable firmware manifest](https://apolloautomation.github.io/CAST_PRO-1/firmware/manifest.json): Version 26.11.3.3 and OTA/factory binary paths, observed 9 November 2026. - [Sendspin protocol](https://www.sendspin-audio.com/): Official protocol context for audio sources, synchronized players and local control. - [Apollo sales and support contact](https://apolloautomation.com/policies/contact-information): Apollo Automation LLC, Versailles, Kentucky, United States, and published support email. - [Apollo shipping policy](https://apolloautomation.com/policies/shipping-policy): In-stock handling and international DAP shipping conditions. - [Apollo return policy](https://apolloautomation.com/policies/refund-policy): 14-day return window, item condition and shipping requirements. ## Article ## A Record Player Becomes a Network Source **Apollo CAST PRO-1 uses built-in WIZnet W5500 Ethernet to bring a line-level audio source into Music Assistant and play network audio through existing speakers.** A record player, CD player or television connects to its analog input. Music Assistant then makes that sound available to players in other rooms, while the CAST PRO-1 can also serve as a playback endpoint. Apollo Automation is a smart-home device company in Versailles, Kentucky, United States. Its [November 4, 2026 launch article](https://apolloautomation.com/blogs/news/cast-pro-1-stream-record-player-every-room-music-assistant) explains that audio input was a recurring request from CAST-1 customers. CAST PRO-1 answers that request with a separate input jack, selectable analog or optical output, and Ethernet integrated into the main product. ![Apollo CAST PRO-1 in its white enclosure, with its audio, USB-C and Ethernet ports visible, photographed on a record player](https://maker.wiznet.io/upload/ckeditor5/755db2e806b74423acb93fabceec47a5.jpg) *Official CAST PRO-1 product photograph on a record player. Photo: *[*Apollo Automation*](https://apolloautomation.com/products/cast-pro-1)*.* The important change is the direction of the audio. The earlier CAST-1 receives network music and feeds an amplifier or powered speaker. **CAST PRO-1 can also originate a stream**, giving an existing physical music collection a place in the same networked system. ## Music Assistant Chooses the Rooms, Sendspin Keeps Time Music Assistant is a music server and player-management application. It runs on a separate host, such as a home server, and lets the listener choose a source and its destination players. Home Assistant provides the device integration, settings and household automations. CAST PRO-1 runs ESPHome firmware on an ESP32-S3. [Sendspin](https://www.sendspin-audio.com/) is the audio protocol that connects compatible sources and players and coordinates synchronized playback. A practical example is a turntable in the living room supplying the kitchen and another room, with all selected players following the same stream. Local playback and control do not require an Apollo cloud account or subscription. The setup needs **Music Assistant 2.10.7 or newer**. Apollo's guide has the user connect power and audio, join Ethernet or Wi-Fi, add the discovered device to Home Assistant, and select the CAST PRO-1 source or player in Music Assistant. The input becomes a source in the Sendspin Source browser; choosing a group determines where it is heard. A turntable connection needs one electrical detail: CAST PRO-1 accepts **line-level audio**. A turntable with a phono-level output needs a phono preamplifier first. The device also has no speaker power amplifier, so its output feeds powered speakers, a receiver or an external amplifier. ## From Analog Input to Ethernet The [input firmware](https://github.com/ApolloAutomation/CAST_PRO-1/blob/main/Integrations/ESPHome/line_in.yaml) configures the Sendspin source for **48 kHz, 16-bit stereo audio**. The ESP32-S3 configures the Sendspin source and keeps a two-second capture buffer in PSRAM, its external working memory. The audio samples then travel through the selected network interface to the Music Assistant system. Two input-streaming modes are exposed in Home Assistant. Compressed mode is the default and uses the Opus audio codec. Lossless mode carries PCM, the uncompressed sample values. Apollo labels lossless mode for Ethernet or strong Wi-Fi; changing the mode restarts the device so the new source configuration takes effect. ![The input path runs from a line-level source through audio conversion and ESP32-S3 Sendspin processing to W5500 Ethernet and Music Assistant](https://maker.wiznet.io/upload/ckeditor5/ef4b64c0a85a47c9b54c340289034347.png) *Authored technical diagram: the input stream travels through the ESP32-S3 and W5500; playback is distributed by Music Assistant.* The two-second capture buffer is a storage allowance for network stalls, not a published end-to-end latency figure. Apollo does not provide a measured input-to-speaker delay in the inspected material. Music distribution is therefore the clearest use case; a television installation also needs an application-specific lip-sync check. Before starting capture, the firmware waits for the analog playback path to stop and checks that the required internal-memory allocations succeed. If memory remains insufficient, it logs a warning rather than starting the capture task. ## W5500 Is the Built-In Wired Interface Apollo's [Core.yaml](https://github.com/ApolloAutomation/CAST_PRO-1/blob/main/Integrations/ESPHome/Core.yaml#L120) explicitly selects `type: W5500` with a **40 MHz SPI clock**. GPIO12 carries clock, GPIO11 MOSI, GPIO13 MISO, GPIO10 chip select, GPIO5 interrupt and GPIO21 reset. This configuration identifies the Ethernet controller independently of the product-page description. ![The actual CAST PRO-1 PCB shows the ESP32-S3 in the center, audio circuitry on the left and the W5500 beside the Ethernet connector on the right](https://maker.wiznet.io/upload/ckeditor5/14250d641d16443e88e716fee6c7b347.jpg) *CAST PRO-1 PCB with ESP32-S3 and W5500 on the same board. Photo: *[*Apollo Automation*](https://apolloautomation.com/products/cast-pro-1)*.* The W5500 carries the audio stream, Home Assistant communication and firmware downloads over the wired network. The ESP32-S3 remains responsible for audio capture, encoding, playback routing and application logic. In this ESPHome implementation the host runs the ESP-IDF/lwIP network stack, with W5500 providing the SPI Ethernet interface. One firmware supports both Ethernet and Wi-Fi. The network priority lists Ethernet first. When a cable is connected, traffic prefers the wired interface; an already joined Wi-Fi connection can remain active so Home Assistant keeps its existing connection. Removing the cable enables Wi-Fi again. If Wi-Fi has no configured network, the firmware suppresses its setup hotspot while Ethernet is connected. That behavior matters in a media cabinet where a network cable is available but wireless coverage varies. The product keeps the same audio and control integration while giving the installation a wired route. **The RJ45 port carries data only: CAST PRO-1 has no PoE and still needs 5 V USB-C power.** ## Input and Output Share One Important Resource CAST PRO-1 has two audio jacks. One is analog input only. The other supports either analog output through a PCM5122 digital-to-analog converter or optical output through a mini-TOSLINK connection, selected in Home Assistant. ![Official CAST PRO-1 connection photograph shows audio cables, USB-C power, Ethernet and LED-strip wiring attached to the port panel](https://maker.wiznet.io/upload/ckeditor5/b2ff83ca2ebe467690c188d78dfe1e0a.jpg) *Audio connections, separate USB-C power, Ethernet and LED-strip wiring. Photo: *[*Apollo Automation*](https://apolloautomation.com/products/cast-pro-1)*.* The firmware reveals a limit that affects wiring: the input converter and analog output share one I2S audio port on the ESP32-S3. **Analog input and local analog output cannot operate together.** When input streaming starts, the firmware routes local playback to the separate optical path and stops the analog DAC speaker path. When input streaming stops, it restores analog output if that was the selected setting. ![A compatibility matrix shows analog input with remote playback or local optical output, while simultaneous local analog output is unavailable](https://maker.wiznet.io/upload/ckeditor5/7dc70ff260724183a81fd2df0637564f.png) *Authored routing guide: optical output remains available while Line In is streaming.* A listener can therefore send a record to analog speakers attached to another player, or listen through the same CAST PRO-1 using optical output. Simply connecting both analog jacks does not create an analog pass-through amplifier. This distinction is useful before choosing cables or assigning a unit to a room. Apollo also added a static playback-delay setting in firmware **26.11.3.3**, published through its firmware manifest. The setting lets Music Assistant compensate when a downstream soundbar or receiver adds processing delay. It begins at zero and is adjusted for the actual playback system. ## A Larger Role in the CAST Family CAST PRO-1 and CAST-1 can join the same Music Assistant playback group. A house can use one PRO unit where a physical source enters the system and simpler CAST-1 units near speakers elsewhere. Apollo's [family comparison](https://apolloautomation.com/blogs/news/cast-pro-1-stream-record-player-every-room-music-assistant#compare) separates the two products by these practical connections. | Connection or role | CAST-1 | CAST PRO-1 | | --- | --- | --- | | Physical audio source | No input | 3.5 mm line-level input | | Speaker connection | Analog line output | Analog or optical output | | Wired network | Optional W5500 Ethernet HAT | W5500 Ethernet built in | | External light strip | Solder pads | 5 V, ground and data terminals | | Listed base price | USD 34.99 | USD 68.99 | The PRO also provides four onboard RGB LEDs, configurable WiZmote remote actions and an optional Bluetooth proxy for Home Assistant. An addressable LED strip can follow playback through ESPHome settings. These features make the enclosure useful beside an existing audio system, while audio input, optical output and built-in Ethernet are the principal reasons to choose it over CAST-1. ## Vendor, Availability, and Price Apollo Automation LLC lists CAST PRO-1 in its [official shop](https://apolloautomation.com/products/cast-pro-1) at **USD 68.99**, observed November 9, 2026. The base package is the device with its case. Power supplies, USB-C cables, network cables and audio cables are separate accessories. Taxes and shipping are calculated at checkout. Apollo publishes a one-to-three-business-day handling policy for in-stock products and a 14-day return policy with condition and shipping requirements. International shipments use DAP terms, so import charges can fall to the recipient. The official support contact is support@apolloautomation.com; setup instructions, firmware installation and community support are linked from the shop. The public repository and web installer provide firmware updates. The inspected stable manifest identifies version 26.11.3.3; source builds currently target ESPHome development code for the new source role. The repository's actual license is **CC BY-NC-SA 4.0**, which includes noncommercial and share-alike conditions. Early owner evidence is limited. A November 8 store review reports successful Sendspin input and output and an LED-matrix experiment using separately installed WLED. That single invited review is useful feedback, but it gives no long-duration reliability test or confirmed Ethernet deployment. ## Related WIZnet Maker Reading The earlier [Apollo CAST-1 with a W5500 Ethernet HAT](https://maker.wiznet.io/ElenaLee/resellers/how-does-apollo-cast-1-use-a-w5500-ethernet-hat-for-wired-sendspin-multi-room-audio/) explains the playback-only member of this family and the development of its combined Wi-Fi/Ethernet firmware. CAST PRO-1 extends that system with a physical audio input and optical output, so the two products can occupy different roles in one installation. ## FAQ **Q. What does CAST PRO-1 use the W5500 for?** The onboard W5500 supplies the wired Ethernet connection for audio streams, Home Assistant communication and firmware updates, connected to the ESP32-S3 over SPI. **Q. Can CAST PRO-1 stream a record player to other rooms?** Yes, through its line-level input and Music Assistant. A turntable without a built-in phono preamplifier needs an external one first. **Q. Can it play its input through its own analog output?** No. Input capture shares the analog output's I2S port; use local optical output or another network player while Line In streams. **Q. Does the Ethernet cable power the device?** No. CAST PRO-1 needs a 5 V USB-C supply; its Ethernet port has no PoE. **Q. What distinguishes CAST PRO-1 from CAST-1?** CAST PRO-1 adds analog input, optical output, built-in Ethernet and LED-strip terminals. CAST-1 remains a simpler analog-output player that can join the same playback groups. --- Source: https://maker.wiznet.io/Benjamin/resellers/how-does-w5500-bring-analog-audio-into-sendspin-on-apollo-cast-pro-1/