Onboard Bluetooth

[wkl3968]

Hello, should I use the pi5 onboard bluetooth or I should use a separate dongle? it seems like the Pi5 bluetooth is not connected to UART0. I also not sure why openauto pro cannot use the Pi4 onboard bluetooth. any perspective and tips what I should do?

[hudiy]

Hello, what exactly is the issue? The built-in Bluetooth module in the Pi5 works with both HFP and A2DP.

[wkl3968]

No issue. I wanted to use the UART0 to com with Teensy. I read that UART0 is tied to Bluetooth for pi4. Hence I wonder if this is true for pi5. If the Bluetooth is not tie to UART0 hence I don't need to disable onboard Bluetooth for UART0 and I don't need a separate Bluetooth dongle.

[hudiy]

No issue. I wanted to use the UART0 to com with Teensy. I read that UART0 is tied to Bluetooth for pi4. Hence I wonder if this is true for pi5. If the Bluetooth is not tie to UART0 hence I don't need to disable onboard Bluetooth for UART0 and I don't need a separate Bluetooth dongle.

As far as we know, it works the same way on both the Pi4 and Pi5. There are several options:

• You can disable the built-in Bluetooth, which frees up the hardware UART. Then use a compatible dongle that supports SCO traffic over HCI.
• You can switch the built-in Bluetooth to use the software UART (dtoverlay=miniuart-bt) and unlock the hardware UART for your needs.
• You can use software UART to communicate with your device (may not work properly with some advanced devices)
• You can use a cheap USB-to-UART dongle (the best option because both your device and Bluetooth will use hardware UART)

It is definitely simpler and cheaper to find a working USB-to-UART dongle than a working Bluetooth dongle.

These are very specific questions about Raspberry Pi's architecture. We can only rely on the official documentation. For this type of question, it's best to use the official Raspberry Pi forum https://forums.raspberrypi.com/, where you can get an answer directly from the engineers.