There are two LEDs on the Core. The big fat one in the middle is a full-color RGB LED that shows you the status of the Core’s internet connection. The other small blue LED is the user LED; it’s hooked up to D7, so when you turn the D7 pin
LOW, it turns on and off, respectively.
The RGB LED could show the following states:
- Flashing blue: Listening mode, waiting for network information.
- Solid blue: Smart Config complete, network information found.
- Flashing green: Connecting to local Wi-Fi network.
- Flashing cyan: Connecting to Spark Cloud.
- High-speed flashing cyan: Spark Cloud handshake.
- Slow breathing cyan: Successfully connected to Spark Cloud.
- Flashing yellow: Bootloader mode, waiting for new code via USB or JTAG.
- White pulse: Start-up, the Core was powered on or reset.
- Flashing white: Factory Reset initiated.
- Solid white: Factory Reset complete; rebooting.
- Flashing magenta: Updating firmware.
- Solid magenta: May have lost connection to the Spark Cloud. Pressing the Reset (RST) button will attempt the update again.
The RGB LED can also let you know if there were errors in establishing an internet connection. A red LED means an error has occurred. These errors might include:
- Two red flashes: Connection failure due to bad internet connection. Check your network connection.
- Three red flashes: The Cloud is inaccessible, but the internet connection is fine. Check our Twitter feed to see if there have been any reported outages; if not, visit our support page for help.
- Four red flashes: The Cloud was reached but the secure handshake failed. Visit our support page for help.
- Flashing yellow/red: Bad credentials for the Spark Cloud. Contact the Spark team (firstname.lastname@example.org).