Documentation
Home Assistant Yellow LEDs
Home Assistant Yellow has 3 LEDs. The red and green LED's behavior is similar to
the red and green LED on a Raspberry Pi. The yellow LED is specific to Home Assistant Yellow.
It indicates Home Assistant specific information.
- Red LED (D4): Power LED
- Green LED (D5): Activity LED
- Yellow LED (D6): Home Assistant Yellow status LED
Power LED (red)
The power LED indicates whether the CM4 is powered. If the LED is off, check
the power supply. If the LED continues to be off,
remove power, and check if the CM4 is properly seated on the Yellow PCB.
Activity LED (green)
The activity LED indicates various firmware and boot loader states at
startup. If CM4 fails to boot, the pattern indicates what the reason is.
Refer to the
LED Warning Flash Codes table of the Raspberry Pi documentation
Once Home Assistant OS has been started, the green LED indicates activity.
Activity is defined as disk (eMMC/NVMe) or any CPU load.
Status LED (yellow)
Home Assistant OS
| Pattern |
Description |
| Off |
System is in EEPROM firmware or boot loader mode. |
| Heartbeat |
Home Assistant OS is running. |
Home Assistant OS Installer for Yellow: LED patterns during installation
| Yellow LED |
Description |
| Off |
System is in EEPROM firmware or boot loader mode. |
| Heartbeat (typically ~30s) |
Installer is booting. |
| Solid on (typically 5s) |
Installer successfully booted and was able to connect to the Internet. |
| Solid on (much longer than 5s) |
After the heartbeat sequence, the yellow LED should be solid on for about 3s and then switch to steady blinking. A yellow LED that does not switch to steady blinking but stays solid on indicates a network issue. |
| Steady blinking (typically ~3-5 min, depending on Internet connection speed). |
Downloading Home Assistant OS and installing onto the eMMC or NVMe. |
| Off |
Installer successfully finished. Green LED will blink a few times before
turning off. Only the red LED remains on. |
