It looks like Google is planning to re-launch the 2nd Generation Chromecast with the support for Bluetooth. This was revealed after an FCC filing went public. According to the filing, Google will re-launch Chromecast with a new FCC ID and will support Bluetooth as well.
The original Chromecast was launched way back in 2015 and it carried FCC ID NC2-6A5, while the new version will carry NC2-6A5B. The specs will be the same and the new version will just have an additional Bluetooth chip.
Original FCC ID: A4RNC2-6A5/IC ID: 10395A-NC26A5has the same board design and mechanical design as new FCC ID: A4RNC2-6A5B/IC ID: 10395A-NC26A5for the Chromecast multimedia device.
The older version supported 2.4Ghz low energy bandwidth Bluetooth but the upcoming version will have full 2.4Ghz Bluetooth support. Unfortunately, the filing notes that the existing Chromecast model will not receive the software update to enable legacy Bluetooth operations due to the following regulatory reasons:
A software change is being implemented to enable legacy Bluetooth operations. Because this new mode requires a new equipment code (DSS) not covered by the original certification for FCC ID A4RNC2-6A5, the new version of device requires a new FCC ID. For clarity, devices bearing FCC ID A4RNC2-6A5 will not receive the software update to enable legacy Bluetooth operations.
So if you’re looking for Bluetooth support on your old Chromecast then, unfortunately, that won’t happen. You will need to shell out money and grab the upcoming Chromecast to get Bluetooth.