Bluetooth

I think I made a topic in the past about this. But it seems I cann’t find it anymore. I try to do some work on the bluetooth stack for RISCOS. One can find the work here. Please note it is work in progress.

https://www.timohartong.riscos.fr/Bluetooth/Bluetooth.html

Hi Timo
How has your work with Bluetooth and RISC OS progressed? Any luck getting anywhere with it?

As Sheldon Cooper from ‘The Big Bang Theory’ states: Everything is better with Bluetooth!

I’d also be very interested to know.

I started from scratch. Just me and the BT standard, which is well over 3000 pages, and some USB captures a few years ago. I’ve been working again on it these last few weeks. I can get communication with the dongle, and through that to a mouse, but I haven’t got as far as getting user data from the mouse.

The trouble with the standard is that, although it tells you what you can send, what you can receive, and how to interpret what you receive, it doesn’t tell you what you need to send in order to get a device going.

@Dave
I also downloaded the Bluetooth specification document a few months back. I was blown away by the size and detail in it.

The Link Manager Protocol is how you establish a connection with a device. I’ll need to look at the document again and see I can make any more sense of it. It’s tough.

There seems to be many different profiles that devices can choose to support to communicate to their host devices. Mouse and Keyboards use the HID profile. It’s apparently very similar to the USB HID, just a wrapper around it apparently. Which given your USB experience is useful. :)

Edit: What RISC OS machine are you working on?

Hi,

What an interest suddenly ;-) that is nice. I’m using the bluez stack ( http://www.bluez.org/ ) this stack is used in a lot of Linux distro’s and used as base in other disto’s like netbsd. Why develop yourself if others have done this ?.
I have come to the stage where I can compile most of the files in the bluez stack. I’m trying to get the chip on the Rpi to work instead of an USB dongle. One of the hurdles I’m trying to tackle is to get the clock to the BT chip. This is normally done by one of the GPCLK clocks
For some items, you have OBEX on top of BT.
Perhaps we can work together to get somewhere. ;-). I heard the name of Dave Higton during the London meeting.

Bluetooth is so important. Everything is Bluetooth enabled. It would be great to use it.

I’m spending today reading up on Bluetooth again and taking notes on what I think is important so I can try and understand it better.

Sounds like Dave has made some great progress. He can see a Bluetooth device, so that’s a great start. I’m guessing he’s using a FOSS Bluetooth stack too.

I remember vaguely that somebody was able to see a list of BT devices but couldn’t get a stable connection with it. I’m using a Rasb Pi 3B+ as test bed.

According to this page pairing is easy!!

In practice I’m sure they are loads of other hidden steps involved.

O yes for example in the bluetooth chip on the Rpi firmware has to be loaded and on low level communication will go back and forth.

Mouse and Keyboards use the HID profile. It’s apparently very similar to the USB HID, just a wrapper around it apparently. Which given your USB experience is useful. :)

Since I posted, I’ve discovered that there are two Protocol/Service Multiplexers for HID: HID Control (0×11) and HID Interrupt (0×13). I looked at a capture for a Bt keyboard and saw bulk transfers setting up and configuring one link for each. I’m trying it with my Bt keyboard. When I can get it to pair, I may get user data flowing. (Or maybe not. I’ve felt like I’m tantalisingly close for weeks now. If I really had been that close, I’d have been there by now.)

What RISC OS machine are you working on?

Raspberry Pi 3B+, which is my main desktop machine nowadays, and a Bt dongle. I have 4 dongles, of which I’ve been using 2. I think the USB protocol for Bt dongles is pretty standard, so any recent dongle ought to work. I’m not attempting to use any built-in Bt chip.

Sounds like Dave has made some great progress. He can see a Bluetooth device, so that’s a great start.

Yes, ish. I wish someone would write a book about writing a Bluetooth stack. I’d buy a copy.

I’m guessing he’s using a FOSS Bluetooth stack too.

Apart from a bit of USB library code from Colin Granville to do the USB transfers, the code is entirely my own. If I had any sense I’d do like Timo and use an already developed stack, but I’m not sensible.

Timo is porting a known, respectable and widely used stack, on the assumption that it implements the Bt protocols. I’m digging through the Bt standard and using some USB captures to/from a USB Bt dongle and some devices, trying to make sense of it all and implement communication my way. The knowledge we gain should be complementary.

Perhaps we can work together to get somewhere.

The most logical place to do it, it seems to me, is via Chatcube. I’ve been on it for some months now; how about you guys? I can create a group, but I need another contact before I can create it.

“If I had any sense I’d do like Timo and use an already developed stack, but I’m not sensible.” => That is relative. Hacking such a protocol and start from scratch can be interesting as well.
Interesting that we do it with two different things you use USB sticks I try the RPi chip. But the protocol should be indeed ‘standard’
" The knowledge we gain should be complementary." => Indeed
Hi do you know if Chatcube is available for MS Windows ?. And what user name you have ?.

Hi do you know if Chatcube is available for MS Windows ?

It isn’t. But if you’re developing for RISC OS, you must have a RISC OS computer. My user name is Dave Higton.

Hi I have installed it on one of the RISC-OS pi . I have as name Timo Hartong if everything went as it should ;-)

Timo, I think using some ready-rolled code could be useful. RISC OS does this sort of thing with the USB and TCP/IP code, so there is plenty of precedent.

BlueZ sounds interesting, but the GPL makes me wonder. Perhaps there is something similar in [Net/Free/Open]BSD?

Alan, would you like to register yourself on Chatcube? Then I can add you to the Bluetooth group.

Richard too, if you’re thinking of contributing.

@Dave
I’m already on ChatCube, under the alias nytrex. But alas, I forgot my password, and have not been able to retrieve it.
I’ve used the built-in ChatCube functionality to reset my password, but I never receive an email with the reset code. I also sent an email to Cloverleaf asking for help.

But, please add me to the group. I’m sure I’ll regain access soon.

And +100 points for writing your own routines to connect Bluetooth devices. Mad, yet amazing. Is it in C or Assembly? Please say C.

Is it in C or Assembly? Please say C.

It’s in C. I have no intention of ever originating any new code for RISC OS in assembly language. (I have recently corrected and updated some assembler, and it wasn’t a pleasant experience.)

I forgot my password, and have not been able to retrieve it.

I’ve alerted Stefan Froehling on Chatcube, in the hope that this prompt will get him to sort it for you.

@Dave
Thank for contacting Stefan to help me regain access to ChatCube.
Good to hear your work is in C. I might be able to understand it. If I’m honest, I’m not sure if I’ll be much help, but I will at least try and be useful where I can.

@Alan: you (should) have email.

@Dave
Yes, thank you I received it, and replied.

Hi Just an update. I don’t have access to a RISC-OS machine at this moment. A part of Bluetooth is in the linux kernel so it has become a bit more complex. Next to that it uses threads and processes ( of course ) so it will take a bit longer.. ;-).