• Home Assistant Yellow
• Heat sink assembly bag
• Ethernet cable
• Power supply

Additionally, make sure you have the following items which are not part of the Kit

• Raspberry Pi Compute Module 4 (CM4)
• USB flash drive

Grounding protects the components from the static electricity that can be naturally present (electrostatic discharge, ESD).

• Always: Touch the working surface before touching electronics.
• Ideally: Use ESD protective equipment, such as ESD table mats and grounding cords.

• Remove the 4 screws on the bottom of the Home Assistant Yellow Kit.
• Keep the thumb screws close by; you will need them again later.

• Make sure the interfaces are facing towards your left.
• Flip the case over.
• Slightly lift off the enclosure on your left.
• Slide the enclosure off towards your right.

• Make sure you have all the components:
• 1 Raspberry Pi Compute Module 4 (CM4)
• 1 heat sink
• 2 thermal pads
• 2 push pins

• Place the board in front of you, the connectors facing to the right.
• Orient the CM4: The CE mark needs to be on the bottom.
• Use the outline of the chips to help find the correct orientation of the CM4. Note: on CM4 Lite variants, the chips on the bottom edge are in a different location.
• Carefully place the CM4 without force.
• The CM4 should fall into place slightly when correctly aligned.

• Press the CM4 board onto the board-to-board connectors until it clicks into place.
• Make sure you press on both sides (the two long edges).
• This requires quite a bit of force. If you don't hear a loud click, it is most likely not fully seated.
• Do a visual check to make sure the CM4 is installed correctly: it needs to run parallel to the Home Assistant Yellow board.

• Remove the protective cover from one side of the square thermal pad.
• Stick the unprotected side onto the SOC (the silver square next to the raspberry icon).
• Remove the protective cover from the top side of the thermal pad.
• Repeat the steps with the rectangular thermal pad. Place it on the memory (the black rectangle next to the SOC).

• Push the 2 plastic push pins into the dedicated hole on the heat sink.
• Start by first aligning the right plastic push pins into the dedicated hole on the carrier board.
• Then, place the heat sink onto the CM4.

• Take the entire board off your workplace and push the pins firmly through the carrier board.
• Ensure that the CM4 is still fully seated after securing the heat sink.

• Place the translucent bottom part of the case onto the table.
• Make sure the two round notches form a line pointing towards the top right corner.

• Place the board onto the bottom part of the case.
• Make sure the USB connectors are facing upwards, away from you.

• Turn the enclosure upside down.
• Then, slide the push buttons into the openings of the case.

• Insert the 4 thumb screws.
• Do not over-tighten the screws.

• Install the Raspberry Pi Imager on your computer as described under https://www.raspberrypi.com/software/
• If your platform doesn't support the Raspberry Pi Imager, you can use another imager (e.g. balenaEtcher) and flash the Home Assistant OS Installer for Yellow directly from GitHub releases.
• If you are using a Raspberry Pi Compute Module 4 (CM4) that already has software on it, this procedure does not work. Ignore this and the following steps.
  • Instead, follow the procedure Option 2: Reinstall Home Assistant OS using rpiboot
  • The reason is that by default, the CM4 tries to boot from the internal eMMC before booting from the USB flash drive.

• Open Raspberry Pi Imager.
• Under Raspberry Pi Device, select Raspberry Pi 4.

• Select Choose OS
• Choose Other specific-purpose OS.
• Choose Home assistants and home automation.
• Choose Home Assistant.
• Choose Home Assistant OS Installer for Yellow.

• Insert the USB flash drive into the computer. Note: The contents of this drive will be overwritten.
• From the dropdown menu, select your USB flash drive.

• Select the Next button to start the process.
• Wait for the Home Assistant OS Installer to be written to the USB flash drive.

• Insert the USB flash drive with the Home Assistant OS Installer into your Home Assistant Yellow Kit.

• Connect the Ethernet cable to your Home Assistant Yellow Kit and make sure it has access to the internet.
• Note: Internet is required because the newly installed Home Assistant OS does not contain all Home Assistant components yet. It downloads the latest version of Home Assistant Core on first start.

• If you are not using PoE, connect the power supply to Home Assistant Yellow Kit.
• For CM4 Lite Home Assistant OS is automatically installed on the NVMe SSD. For regular CM4s Home Assistant OS is installed onto the eMMC by default.
• Advanced: Forcing installation onto the NVMe SSD when using CM4 with eMMC:
  Press the blue button while the yellow LED is on constantly (during the 5s window, see next step).

• Wait for Home Assistant Yellow to start booting from the USB flash drive.
• During boot, the Yellow LED is blinking steadily.
• Once the installer is ready, the yellow LED will be constantly on for 5 seconds.
• If the LED is stuck in steady blinking or constantly on for an extended period of time, this could indicate that the installer cannot connect to the internet. Follow this procedure to troubleshoot.

• During installation the LED will blink fast.
• Wait for Home Assistant Yellow to finish installing the Home Assistant Operating System.
• Once the installer finished installing Home Assistant Operating System, only the red LED will be on.

• Remove the USB flash drive.
• Remove the power cable.

• Reinsert the Ethernet cable.
• Reinsert the power cable to start Home Assistant (if PoE is not used).

• Initial startup may take a while, depending on your internet connection.
• Install the app
  To access Home Assistant from your mobile device, use the QR code to locate the app in the app store.
• Select your Home Assistant Server:
  • Mobile: Confirm the IP address detected by the app. E.g. http://192.168.1.196:8123
  • Desktop: Visit http://homeassistant.local:8123 to access the Home Assistant frontend.
• The Home Assistant frontend guides you through the initial onboarding.
• For further information, refer to the instructions provided under https://www.home-assistant.io/getting-started/onboarding/.