A chip shortage still impacts the availability of the CM4. Our recommendation is to use rpilocator. This website tracks the stock of official Raspberry Pi distributors. Follow them on Twitter and enable push notifications. You will be notified as soon as the bot tweets that products are in stock.
We recommend purchasing a Raspberry Pi Compute Module 4 with the following characteristics:
- Min. 2 GB of RAM.
- Min. 16 GB of eMMC flash space.
- If you opt for the CM4 Lite: as it does not have an eMMC module, you must use an NVMe SSD hard drive. Some users reported that the following SSDs are not working on the Home Assistant Yellow.
Yellow has an M.2 M-Key connector which supports NVMe SSDs with M-Keying and length of 2230, 2242, 2260, or 2280.
- The Raspberry Pi CM4 has a single lane PCIe 2.0 (Gen 2.0 x1). PCIe is backwards compatible.
- NVMe SSDs supporting a newer generation of PCIe or more, supporting multiple lanes, should generally work (e.g. Samsung 970 EVO Plus MZ-V7S500BW with a PCIe Gen 3.0 x4 interface is known to work).
A high-end NVMe is not required, since the CM4 PCIe interface is only Gen 2.0 x1. A low-cost NVMe is typically good enough. If you are new to NVMe SSDs and struggle to make a decision: no issues have been reported about Samsung NVMe SSDs.
Check below to see a list of models which have been reported to NOT work currently:
All M.2 SATA SSDs are NOT supported. Besides the following NVMe SSDs are known to NOT work:
- WD_BLACK SN850X (1TB)
- WD_BLACK SN770
- WD_BLACK SN750 SE
- SK Hynix BC711
- Crucial P2 CT250P2SSD8
- Lexar NM620
- Samsung 980 Pro
The Home Assistant Yellow team officially supports ZHA (Zigbee Home Automation), the Zigbee stack integrated into Home Assistant Core.
The Zigbee2MQTT project has experimental support (in beta stage) for the Silicon Labs radio on Home Assistant Yellow. With this setting Zigbee2MQTT is known to work on Home Assistant Yellow.
Note: The Zigbee Home Automation integration is active by default! If you are using Zigbee2MQTT, remember to delete and ignore the discovered Zigbee Home Automation integration to avoid interference.
Note: When setting up Zigbee2MQTT with the Home Assistant Yellow, you will need to configure the adapter type in Zigbee2MQTT. Make sure the following is present in your Zigbee2MQTT configuration:
serial: adapter: ezsp port: /dev/ttyAMA1 baudrate: 115200 rtscts: true
The Zigbee/Thread (IEEE 802.15.4) radio is directly connected via serial port to the Raspberry Pi Compute Module 4 on
/dev/ttyAMA1. Note that there is no
/dev/serial/by-id path for this serial port as its not connected through USB. The above tty path will remain static.
The Duracell CR2032 shipped with Home Assistant Yellow is estimated to last 10 years or more (with self-discharge taken into account). Replacement likely won't be necessary within the product's lifetime. If your RTC does not show the correct date, this is likely because the initial time synchronization failed. Make sure that your Internet router does not block NTP (Network Time Protocol) traffic.