The BTU-3.1.3 is a major firmware update to the BTU product. This update provides better handling of the Bluetooth interface and sets it up for future updates.
Some of the improvements include better re-connecting during
loss of signal. Currently if the signal between the BTU and the
Bluetooth phone are lost for a long enough time, you need to
manually reconnect or power cycle the radio. Examples of
where this could happen is at a car show with music playing
and the user walks too far away. With this new firmware, the BTU will continue to retry
connecting to the device so when you walk back into range, the BTU will automatically
reconnect and continue from where it was. Another typical example would be leaving the radio
playing for a passenger in the vehicle why you go to pay for gasoline or quickly grab
Another improvement is system sounds on the phone will no longer interrupt the radio. Things like keyboard clicks will now not go through to the radio. The user will no longer have to mute their phone to eliminate this nuisance.
This firmware now takes control of all timing for the Bluetooth link. Things like how long the
radio stays on the Bluetooth after a sound is made is now handled directly by the BTU. Now
when things like “Bluetooth Disconnected” come through the radio, after the announcement is
finished the radio will immediately return to what it was doing. No longer do you have to wait
for an arbitrary timeout period controlled by the phone.
When you pause or stop music, the radio will wait for the exact same 6 seconds as it does for USB and then return.
These improvements will be rolled into the BT/BTL devices in a future release.