Esp-idf: [TW#12792] Feature Request: BT PAN Over Ethernet (IDFGH-1337)

[GeorgeIoak]

This might not be the most common usage but I was hoping if I posted the request I could see if anyone had worked on it. What this would do is allow a device (say a tablet) to connect over Bluetooth to the ESP32 and then send packets over Bluetooth to the internet through a wired ethernet connection.
This is useful for small data and lowest power since Bluetooth communication would be lower power than WiFi

[negativekelvin]

Might be a start: https://github.com/kuc-arc-f?tab=repositories

[GeorgeIoak]

It definitely looks like it's along the lines of what I'm after. I'll brush up on my Japanese and see what he's got done.

[benjaminaigner]

Hi,

I'm currently working with 6lowpan over BLE, so I'm already sending MQTT
messages via Bluetooth to a host (no Ethernet by now, but this should be
no problem).

Are you interested?

On 20/05/17 21:27, George Ioakimedes wrote:

This might not be the most common usage but I was hoping if I posted the request I could see if anyone had worked on it. What this would do is allow a device (say a tablet) to connect over Bluetooth to the ESP32 and then send packets over Bluetooth to the internet through a wired ethernet connection.
This is useful for small data and lowest power since Bluetooth communication would be lower power than WiFi

[GeorgeIoak]

Yes, I'm very interested in getting this working. Should we start a repo or how would you want to work together?

[mringwal]

Another option you might try is to run BTstack instead of the Bluedroid stack on the ESP32 and then port the example/panu_demo.c to the IP stack of ESP-IDF. This would use Bluetooth Classic - more speed, but also requires more power than 6LowPAN over BLE.

[GeorgeIoak]

@mringwal Thanks that looks interesting but I didn't see the ESP32 as one of the supported processors on the BTstack site.

[benjaminaigner]

Hi,
sry for this late reply.
I will upload it to my account ASAP (comments, ...).
My implementation uses BTStack (thx @mringwal for that!), it depends on you if you want to spend the effort on implementing/using Bluedroid

I will post the link when I'm finished!
I'm looking forward for feedback, improvements and wishes ^^

[GeorgeIoak]

@benjaminaigner Thanks! I look forward to checking it out. I've got a ENC28J60 breakout board and I just ordered up some more ESP32 modules to mess with.

[mringwal]

@GeorgeIoak it's not on the main README.md yet, but check out ports/esp32.
I have been waiting for a bug in the ESP32 low level Bluetooth implementation to get fix and still got crashes I'd like to analyse and post issues about, before I add it to the front page. It's working well for @benjaminaigner it seems.

[benjaminaigner]

@mringwal: I have no problems, even with an "old" version of BTStack!
I sent more than 5000 MQTT-SN packets (the MQTT-Spy stops counting after 5000 :-)), no problems.

I've posted the network interface for RFC7668 at savannah (lwIP git), you need to put this driver in components/lwip/netif:

http://savannah.nongnu.org/bugs/?51094

I will post the implementation with BTStack via the university's GIT server soon!

EDIT: Oh, and the header files need to be components/lwip/include/lwip/netif

[benjaminaigner]

Hi again, you can clone my current implementation here:

https://es.technikum-wien.at/aignerb/esp32-rfc7668-public

Best wishes

BTW: Issue tracking is disabled, so either we discuss problems here or via another channel

[GeorgeIoak]

I need to setup a new machine with the ESP-IDF so I'll work on that today and clone your repo.

[GeorgeIoak]

I got my Windows machine setup finally and I cloned your repo into my Github account. I tried to compile the project but it looks like your repo doesn't include the full btstack so I wanted to check how you integrated it and if you used the ESP32 branch that @mringwal pointed me to

[benjaminaigner]

I'm not sure if I'm allowed to include BTStack within my repo. So I cloned the official BTStack repo from bluekitchen and put that to a folder in my projects directory. Please take care of modifying the components.mk file in my repo to reflect the relative path to the BTStack root.

[mringwal]

@benjaminaigner hi. just had a first look. It's surprisingly little code, congrats! I'll send more comments by mail. anyway. I don't see "rfc7668.c and rfc7668.h/rfc7668_opts.h" in the repo. Where to get these, or are they just missing?

[GeorgeIoak]

Is it perhaps forked from here

[benjaminaigner]

@GeorgeIoak other way, I posted it there :-)

You can use these files from the link @GeorgeIoak (and I) posted.

I'm currently cleaning up the code, to have it in the master branch of lwIP.

[mringwal]

@benjaminaigner ouch.. right! You could add the savannah link to the gitlab readme (and update it once there's progress.

[benjaminaigner]

Hi again, I've updated my repo with the example code. The current lwIP files are now included (as they are currently provided to lwip as patch).

So:

• Clone my repository ( https://es.technikum-wien.at/aignerb/esp32-rfc7668-public/ )
• Clone BTStack ( https://github.com/bluekitchen/btstack )
• Follow the instructions in my README

Greetings

[Yulong-espressif]

@GeorgeIoak I think you can try to transplant the contiki(a stack of 6lowpan, the github link is https://github.com/contiki-os/contiki) to the IDF, mabey it will helpful for you. Thanks.

[nottledim]

I'm a bit late to the party but I'm trying to build the Benjamin Aigner test/demo https://es.technikum-wien.at/aignerb/esp32-rfc7668-public

And I get this compile error: No rule to make target '/home/beni/sync/Projects/FH/esp/esp-idf/components/esp32/./brownout.c', needed by 'brownout.o

I can't find where that path originates in the repo. Can somebody help!

[benjaminaigner]

@nottledim
I'm currently not working on this proof of concept, simply because I'm waiting for BLE Mesh.
But this build error is mostly related to a absolute path I wrote somewhere (this is my personal dir tree).
Please do a "make clean" and "make" again & if it does not work, please post the resulting log here.
BTW: I cannot guarantee this is working with the latest esp-idf!

[nottledim]

Thanks for responding. I've given up with bluetooth for now. The learning curve was too steep to justify and btstack doesn't support PAN on esp yet.

[EvanKrall]

I took a crack at getting PAN on ESP32 via btstack working:

https://github.com/EvanKrall/panu_demo_esp32

The core of it is https://github.com/EvanKrall/panu_demo_esp32/blob/efbc0a2b1787ffdc9d9f07b95d7c03d3a411f31e/main/btstack_network_lwip.c, which implements the same functions as e.g. https://github.com/bluekitchen/btstack/blob/789c3c6f9c87f37dfab2df5d9ed2c74951d065fd/platform/posix/btstack_network_posix.c -- those defined in https://github.com/bluekitchen/btstack/blob/789c3c6f9c87f37dfab2df5d9ed2c74951d065fd/src/btstack_network.h

I'm not aiming to forward to Ethernet like you are, just to use PAN like softAP.

This repo also sets up a dhcp server and the example http server.

It compiles, runs without crashing, and I can pair to it with iOS and macOS, but I am unable to access the web server or get assigned an address by DHCP. I'm sure I'm just missing something silly.

[mringwal]

Hi Evan! Thanks for sharing. I've also spend some time on providing an HTTP server over BTstack's PAN using lwIP for all all platforms. I guess there could have been some synergies.

Anyway, I've started with plain BTstack and added lwIP in the NO_SYS = 1 bare metal version (to have something that works anywhere). It also adds a DHCP server and runs on desktop system (mac/linux/win) and some NOOS platforms.

After pondering for a while how we could support multiple PAN demos, but at the same time trying to hide the fact that we're using lwIP, I gave up, and pulled lwIP into the examples.
However, the BNEP packet handling is always the same for a given TCP/IP stack, so I've created a bnep_lwip.c adapter that is used instead of the btstack_network.h interface. The PAN HTTP + DHCP demo is here: https://github.com/bluekitchen/btstack/blob/develop/example/pan_lwip_http_server.c

Now, back to ESP32. I've also tried to integrate it with esp-idf, but it's not working yet - there seems to be bug that causes a crash on the first HTTP request. In fact, I wanted to look at it later today and try to find the bug. If you beat me to it, please let me know, it's on lwip-esp32 branch with the bnep_lwip.c adapter in platform/lwip.c

You can check it out

[mringwal]

Found it! Well, it was a misconfiguration of the ESP32 port that was only relevant to PAN/BNEP.
Please try pan_lwip_http_server from current develop. Works for me! :)

[RandyLoeb]

It seems like the discussion here is providing internet through the esp32 via bluetooth, I'm trying to pursue the reverse direction: esp32 uses bluetooth to get internet via some other device (phone, laptop) that bridges (I think this sometimes called tethering over bt). But I think there's common interest in getting a tcp/ip stack on top of bt? Curious if someone knows of sample code for my use case? Thanks

[mringwal]

@RandyLoeb For Bluetooth Tethering, the UI to pick a smartphone can be a bit tricky. On the other hand, the smartphone could connect to the ESP32 which then could remember the address of the smartphone.

That aside, the panu_demo in BTstack shows how to create an outgoing connection or might already do what you're looking for.

[nicolasgarnet]

@RandyLoeb Have you found any code sample that provides internet access to ESP32 through phone via bluetooth tethering ? I'm also looking to do something like this.