Raspberry Pi 3 B+ Bluetooth Serial Capability

[dbaker2929]

Hello, I'm new to these forums and to Raspberry Pi development techniques. I am trying to make a USB device attached to my Raspberry Pi 3 B+ visible over Bluetooth. I have successfully created a Bluetooth serial connection with my laptop running Windows 10, but I have been unable to find anything to help me complete my final objective. Any help is greatly appreciated.

[Douglas6]

I'm not quite able to get my head around your "final objective". Establishing a serial connection over Bluetooth between a Pi and a PC requires only a couple of steps, but that in no way will make a USB device attached to the Pi "visible" to the PC.

Perhaps with more details on what exactly you're trying to suggest, someone could provide more help.

[dbaker2929]

Certainly. The USB device connected to the pi interacts with a program operated from the pc. I want to be able to allow that to happen over the bluetooth connection instead of having to plug it in to the laptop directly. I have established serial over bluetooth using RFCOMM and I've achieved back door access to my usb device using minicom.

[Douglas6]

So is there still a question, or have you worked it out?

[dbaker2929]

I haven't fixed it yet. I simply have good communication to the pi from both ends. I still need to bridge that gap and I'm at a loss honestly.

[Andyroo]

I think like Douglas6 we are not sure what you have - program name, device details etc would help...

From the notes above are these correct:

1) You have a Pc with program that connects to the device by usb
2) The PC and Pi are connected together via Bluetooth
3) The device connects to the Pi and you can issue instructions via minicom

You are stuck on:
A) How to get the PC to send over Bluetooth (this is way out of this forums skill unless someone here knows the program)
B) How to capture the data from Bluetooth and send it to the device

[dbaker2929]

Actually the usb device sends data via a serial com port connection. I am attempting to us the pi to send that same data over bluetooth to the pc.

[Andyroo]

I’m well baffled now.

Can you please sketch or explain how everything is connected and what it is?

My Pi computers do do not come with a crystal ball and the news seems the Pi 4 will not have one either (see other posts for the Great Disaster to understand the reference / context).

[Douglas6]

You'll need a program running on the Pi that opens both the USB serial port and the rfcomm virtual serial port, and then monitors (reads) one, and writes that data to the other. And probably vice-versa. Relatively easy to do with Python and the PySerial library. Other languages, other libraries, but it sounds like straightforward serial communications programming.

[blimpyway]

You can also try serial virtual port forwarding over tcp (wifi/eth).
I think there are more utilities available for this setup than for bluetooth on both windows and linux.

[dbaker2929]

Thank you everyone for all your help! I did have to abandon bluetooth for this project. I ended up turning the pi into a wireless access point and using ser2net to forward the usb port. Thanks again!