Agilent U1177A IR to BT adapter

[Tony_G]

Hey All,

I just grabbed a U1177A IR to BT adapter for the U1253B that I saved from the dumpster (dead OLED screen).

It connects to my Android phone (Samsung S20+) but my Windows machine doesn't see it - I'm running Windows 11 with the motherboard BT turned on (Asus rog strix z690-f).

As far as I can tell it should be discoverable but I'm wondering if there is some setting on the PC/Motherboard that I need to turn on for compatibility.

Does anyone have any ideas?

Thanks,

TonyG

[Kean]

I don't know the device, but it uses BT 2.1 Serial Port Profile which should be supported by most Bluetooth enabled computers and Windows 11.

Maybe you need to delete the pairing on your Android device.  Only one device can be connected at once.

[Tony_G]

Thanks, appreciate the response.

I'm leaning towards something in the HW or BT Stack right now - I dug up an old Surface Tablet that runs Win 10 with a Qualcomm BT chipset in it and a 2019 Razer that uses the Intel one. That Razer is running Windows 11.

Surface QC & Win 10 - U1177A is discoverable and can be connected
Razer Intel & Win 11 - U1177A is not discoverable

I think the next step is to see if I can get an old BT USB dongle and rule out the Intel BT HW.

TonyG

[Kean]

I think the next step is to see if I can get an old BT USB dongle and rule out the Intel BT HW.

Agreed.  Most old USB dongles should support BT 2.1, but may not support BLE.
Windows 11 is supposed to still have full support just like Win 10, but I've avoided upgrading any of my PCs.

[Tony_G]

Quick update on this - I got a couple of old BT dongles from back in the day when RPi's didn't have BT on them and tried those.

My Win11 machine did not like that at all - Plugging in the dongles basically took the Intel BT drivers down and then rebooting the machine let the Intel drivers take down the Broadcom ones - Bit of a fight back and forth...

Anyway, I thought well maybe I should run one of the BT dongles under a Win10 VM I have - So I powered up VMWare Workstation Pro, loaded in a Win10 VM, and opened the device manager to get ready to plug in the dongle.

I noticed that there was already some virtualized BT hardware there and decided to see if that could see the U1177A.

Yes, it could - It was discoverable there so I tried connecting, and when the Win10 instance popped a connection pin dialog, so did the Win11 host. Typing in the pin connected the U1177A to the Win11 machine and now it works on the Win11 desktop without a problem:



So I think this pretty much tightens the problem to the Win11 BT stack having some problem with the discovery of the U1177A because once connected it works fine.

Anyway, hope this might help someone else who has this issue in the future.

TonyG

[Tony_G]

I really wanted to nail down the guilty party here so I flattened the machine and installed Win10 on it - The result was being able to see the U1177A, Connect to it, and run the App.

I then flattened it again and installed Win11 on it and interestingly enough the BT HW was not detected by Win11 for that motherboard - However, it was once I installed the Intel drivers (this isn't the case for Win10 where it was just found by the default install) - The U1177A was not detected and couldn't be connected to.

So there is certainly something wrong with the Win11 BT Stack - Either the Windows 11 bits themselves or the Intel drivers for that HW. In any case, I can get it to work by forcing a discovery via a VM on the HW so a partial win is still a win.

As someone once said a long time ago, in a place far, far away:

Remember, fear of BT dev incompetence leads to anger, Anger leads to hate, Hate leads to suffering through trying to find a BT stack implementation that works correctly...

TonyG

[Kean]

I've not used Win11 myself, but I have seen mentions that by default it will only discover BLE devices.
As the U1177A is BT 2.1 SPP, you likely need to enable the advanced bluetooth device discovery mode. 

In case it isn't obvious, do a web search to find step-by-step instructions - e.g.
https://www.elevenforum.com/t/enable-or-disable-advanced-bluetooth-devices-discovery-in-windows-11.14237/

[Tony_G]

That was exactly the problem - Switching to Advanced and the U1177A is discoverable now.

Thanks for the help, Appreciate it.

[Kean]

Awesome.  Good to know it worked.