|
| From: | Bas Prins |
| Subject: | Re: [lwip-users] lwip-users Digest, Vol 214, Issue 4 |
| Date: | Mon, 7 Jun 2021 19:51:03 +0200 |
Send lwip-users mailing list submissions to
lwip-users@nongnu.org
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.nongnu.org/mailman/listinfo/lwip-users
or, via email, send a message with subject or body 'help' to
lwip-users-request@nongnu.org
You can reach the person managing the list at
lwip-users-owner@nongnu.org
When replying, please edit your Subject line so it is more specific
than "Re: Contents of lwip-users digest..."
Today's Topics:
1. Re: pppos sent packets optionally start with 0x7e, why?
(Sylvain Rochet)
2. Re: pppos sent packets optionally start with 0x7e, why?
(Bas Prins)
----------------------------------------------------------------------
Message: 1
Date: Mon, 7 Jun 2021 18:27:53 +0200
From: Sylvain Rochet <gradator@gradator.net>
To: Mailing list for lwIP users <lwip-users@nongnu.org>
Subject: Re: [lwip-users] pppos sent packets optionally start with
0x7e, why?
Message-ID: <20210607162753.GA27976@gradator.net" target="_blank">20210607162753.GA27976@gradator.net>
Content-Type: text/plain; charset="utf-8"
Hi,
On Mon, Jun 07, 2021 at 04:19:45PM +0200, Bas Prins wrote:
> Dear,
>
> I was looking at the data being sent/received over uart when ppp is being
> negotiated. I was surprised to see that the received byte stream is always
> wrapped in 0x7e bytes (leading + trailing).
>
> But for some reason this is not the case for the bytes lwip sends
> (/provides to my sio_write function). Even stronger, sometimes it does
> start with a leading 0x7e, sometimes it doesn't.
>
> On the wiki I read:
>
> "PPP packets all start and end with 0x7E. If you don't see these, something
> is wrong with your low level driver"
This is not wrong per se, but added to that the end of a frame can also
be the start of the next frame. That is, the following sequence are two
valid frames:
0x7e ........ 0x7e ........ 0x7e
What is also usually done is to prepend a 0x7e if the serial link as
been idle for a while to clear any received noise. We do so in lwIP.
> When I look at fsm.c where the PPP header is created, I don't see 0x7e
> being added as part of the opening header.
HDLC flags and byte stuffing are processed in pppos.c. You are mixing up
PPP and HDLC but I agree the border between them is blurry ! :)
> pppos works, lwip works, I can open sockets, download from FTP, etc. So
> what's the deal with this? Should I investigate further and is there a bug
> sitting in my code? Or is this "perfectly normal" behavior and is the wiki
> wrong?
This is normal!
Sylvain
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <https://lists.nongnu.org/archive/html/lwip-users/attachments/20210607/dcae727b/attachment.sig>
------------------------------
Message: 2
Date: Mon, 7 Jun 2021 19:00:25 +0200
From: Bas Prins <bas.prins3@gmail.com>
To: lwip-users@nongnu.org
Subject: Re: [lwip-users] pppos sent packets optionally start with
0x7e, why?
Message-ID:
<CAK+1jk0kFoCH7VbyLr=H1Dz1JjntE58rk07nQz_JDqc+we9LAw@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
I think the CSV attachment was dropped by server. Trying to add the CSV as
plain text below.
Async Serial == RX
Async Serial [1] == TX
Leading 0x7E byte is not provided by LWIP in when it calls sio_write.
name type start_time duration data
Async Serial [1] data 5.80629 8.25E-05 0x41
Async Serial [1] data 5.806378 8.25E-05 0x54
Async Serial [1] data 5.806466 8.25E-05 0x0D
Async Serial [1] data 6.936377 8.25E-05 0x2B
Async Serial [1] data 6.946236 8.25E-05 0x2B
Async Serial [1] data 6.95636 8.25E-05 0x2B
Async Serial data 7.865252 8.25E-05 0x0D
Async Serial data 7.865339 8.25E-05 0x0A
Async Serial data 7.865426 8.25E-05 0x4F
Async Serial data 7.865513 8.25E-05 0x4B
Async Serial data 7.865599 8.25E-05 0x0D
Async Serial data 7.865686 8.25E-05 0x0A
Async Serial [1] data 7.869666 8.25E-05 0x41
Async Serial [1] data 7.869754 8.25E-05 0x54
Async Serial [1] data 7.869842 8.25E-05 0x4F
Async Serial [1] data 7.86993 8.25E-05 0x0D
Async Serial data 7.871056 8.25E-05 0x0D
Async Serial data 7.871143 8.25E-05 0x0A
Async Serial data 7.87123 8.25E-05 0x43
Async Serial data 7.871317 8.25E-05 0x4F
Async Serial data 7.871403 8.25E-05 0x4E
Async Serial data 7.87149 8.25E-05 0x4E
Async Serial data 7.871577 8.25E-05 0x45
Async Serial data 7.871664 8.25E-05 0x43
Async Serial data 7.871751 8.25E-05 0x54
Async Serial data 7.871837 8.25E-05 0x20
Async Serial data 7.871924 8.25E-05 0x31
Async Serial data 7.872011 8.25E-05 0x31
Async Serial data 7.872098 8.25E-05 0x35
Async Serial data 7.872185 8.25E-05 0x32
Async Serial data 7.872271 8.25E-05 0x30
Async Serial data 7.872358 8.25E-05 0x30
Async Serial data 7.872445 8.25E-05 0x0D
Async Serial data 7.872532 8.25E-05 0x0A up until here is AT commands to
put modem in ppp. That succeeded here.
Async Serial [1] data 7.895673 8.25E-05 0x7E First packet sent over uart
from STM
Async Serial [1] data 7.895761 8.25E-05 0xFF
Async Serial [1] data 7.895849 8.25E-05 0x7D
Async Serial [1] data 7.895937 8.25E-05 0x23
Async Serial [1] data 7.896025 8.25E-05 0xC0
Async Serial [1] data 7.896113 8.25E-05 0x21
Async Serial [1] data 7.896201 8.25E-05 0x7D
Async Serial [1] data 7.896289 8.25E-05 0x21
Async Serial [1] data 7.896377 8.25E-05 0x7D
Async Serial [1] data 7.896465 8.25E-05 0x21
Async Serial [1] data 7.896553 8.25E-05 0x7D
Async Serial [1] data 7.896641 8.25E-05 0x20
Async Serial [1] data 7.896729 8.25E-05 0x7D
Async Serial [1] data 7.896817 8.25E-05 0x34
Async Serial [1] data 7.896905 8.25E-05 0x7D
Async Serial [1] data 7.896993 8.25E-05 0x22
Async Serial [1] data 7.897081 8.25E-05 0x7D
Async Serial [1] data 7.897169 8.25E-05 0x26
Async Serial [1] data 7.897257 8.25E-05 0x7D
Async Serial [1] data 7.897345 8.25E-05 0x20
Async Serial [1] data 7.897433 8.25E-05 0x7D
Async Serial [1] data 7.897521 8.25E-05 0x20
Async Serial [1] data 7.897609 8.25E-05 0x7D
Async Serial [1] data 7.897697 8.25E-05 0x20
Async Serial [1] data 7.897785 8.25E-05 0x7D
Async Serial [1] data 7.897872 8.25E-05 0x20
Async Serial [1] data 7.89796 8.25E-05 0x7D
Async Serial [1] data 7.898048 8.25E-05 0x25
Async Serial [1] data 7.898136 8.25E-05 0x7D
Async Serial [1] data 7.898224 8.25E-05 0x26
Async Serial [1] data 7.898312 8.25E-05 0x40
Async Serial [1] data 7.8984 8.25E-05 0xB1
Async Serial [1] data 7.898488 8.25E-05 0x9C
Async Serial [1] data 7.898576 8.25E-05 0xE9
Async Serial [1] data 7.898664 8.25E-05 0x7D
Async Serial [1] data 7.898752 8.25E-05 0x27
Async Serial [1] data 7.89884 8.25E-05 0x7D
Async Serial [1] data 7.898928 8.25E-05 0x22
Async Serial [1] data 7.899017 8.25E-05 0x7D
Async Serial [1] data 7.899105 8.25E-05 0x28
Async Serial [1] data 7.899193 8.25E-05 0x7D
Async Serial [1] data 7.899281 8.25E-05 0x22
Async Serial [1] data 7.899369 8.25E-05 0x38
Async Serial [1] data 7.899457 8.25E-05 0xB7
Async Serial [1] data 7.899545 8.25E-05 0x7E end first packet
Async Serial data 7.900403 8.25E-05 0x7E first received ppp packet on rx
line
Async Serial data 7.90049 8.25E-05 0xFF
Async Serial data 7.900576 8.25E-05 0x7D
Async Serial data 7.900663 8.25E-05 0x23
Async Serial data 7.90075 8.25E-05 0xC0
Async Serial data 7.900837 8.25E-05 0x21
Async Serial data 7.900924 8.25E-05 0x7D
Async Serial data 7.90101 8.25E-05 0x21
Async Serial data 7.901097 8.25E-05 0xE5
Async Serial data 7.901184 8.25E-05 0x7D
Async Serial data 7.901271 8.25E-05 0x20
Async Serial data 7.901358 8.25E-05 0x7D
Async Serial data 7.901444 8.25E-05 0x39
Async Serial data 7.901531 8.25E-05 0x7D
Async Serial data 7.901618 8.25E-05 0x22
Async Serial data 7.901705 8.25E-05 0x7D
Async Serial data 7.901792 8.25E-05 0x26
Async Serial data 7.901878 8.25E-05 0x7D
Async Serial data 7.901965 8.25E-05 0x20
Async Serial data 7.902052 8.25E-05 0x7D
Async Serial data 7.902139 8.25E-05 0x20
Async Serial data 7.902226 8.25E-05 0x7D
Async Serial data 7.902312 8.25E-05 0x20
Async Serial data 7.902399 8.25E-05 0x7D
Async Serial data 7.902486 8.25E-05 0x20
Async Serial data 7.902573 8.25E-05 0x7D
Async Serial data 7.90266 8.25E-05 0x23
Async Serial data 7.902746 8.25E-05 0x7D
Async Serial data 7.902833 8.25E-05 0x25
Async Serial data 7.90292 8.25E-05 0xC2
Async Serial data 7.903007 8.25E-05 0x23
Async Serial data 7.903094 8.25E-05 0x7D
Async Serial data 7.90318 8.25E-05 0x25
Async Serial data 7.903267 8.25E-05 0x7D
Async Serial data 7.903354 8.25E-05 0x25
Async Serial data 7.903441 8.25E-05 0x7D
Async Serial data 7.903528 8.25E-05 0x26
Async Serial data 7.903614 8.25E-05 0x26
Async Serial data 7.903701 8.25E-05 0xA6
Async Serial data 7.903788 8.25E-05 0x32
Async Serial data 7.903875 8.25E-05 0x2F
Async Serial data 7.903962 8.25E-05 0x7D
Async Serial data 7.904049 8.25E-05 0x27
Async Serial data 7.904135 8.25E-05 0x7D
Async Serial data 7.904222 8.25E-05 0x22
Async Serial data 7.904309 8.25E-05 0x7D
Async Serial data 7.904396 8.25E-05 0x28
Async Serial data 7.904483 8.25E-05 0x7D
Async Serial data 7.904569 8.25E-05 0x22
Async Serial data 7.904656 8.25E-05 0xD7
Async Serial data 7.904743 8.25E-05 0x73
Async Serial data 7.90483 8.25E-05 0x7E
Async Serial data 7.904917 8.25E-05 0x7E
Async Serial data 7.905003 8.25E-05 0xFF
Async Serial data 7.90509 8.25E-05 0x7D
Async Serial data 7.905177 8.25E-05 0x23
Async Serial data 7.905264 8.25E-05 0xC0
Async Serial data 7.905351 8.25E-05 0x21
Async Serial data 7.905437 8.25E-05 0x7D
Async Serial data 7.905524 8.25E-05 0x22
Async Serial data 7.905611 8.25E-05 0x7D
Async Serial data 7.905698 8.25E-05 0x21
Async Serial data 7.905785 8.25E-05 0x7D
Async Serial data 7.905871 8.25E-05 0x20
Async Serial data 7.905958 8.25E-05 0x7D
Async Serial data 7.906045 8.25E-05 0x34
Async Serial data 7.906132 8.25E-05 0x7D
Async Serial data 7.906219 8.25E-05 0x22
Async Serial data 7.906305 8.25E-05 0x7D
Async Serial data 7.906392 8.25E-05 0x26
Async Serial data 7.906479 8.25E-05 0x7D
Async Serial data 7.906566 8.25E-05 0x20
Async Serial data 7.906653 8.25E-05 0x7D
Async Serial data 7.906739 8.25E-05 0x20
Async Serial data 7.906826 8.25E-05 0x7D
Async Serial data 7.906913 8.25E-05 0x20
Async Serial data 7.907 8.25E-05 0x7D
Async Serial data 7.907087 8.25E-05 0x20
Async Serial data 7.907173 8.25E-05 0x7D
Async Serial data 7.90726 8.25E-05 0x25
Async Serial data 7.907347 8.25E-05 0x7D
Async Serial data 7.907434 8.25E-05 0x26
Async Serial data 7.907521 8.25E-05 0x40
Async Serial data 7.907608 8.25E-05 0xB1
Async Serial data 7.907694 8.25E-05 0x9C
Async Serial data 7.907781 8.25E-05 0xE9
Async Serial data 7.907868 8.25E-05 0x7D
Async Serial data 7.907955 8.25E-05 0x27
Async Serial data 7.908042 8.25E-05 0x7D
Async Serial data 7.908128 8.25E-05 0x22
Async Serial data 7.908215 8.25E-05 0x7D
Async Serial data 7.908302 8.25E-05 0x28
Async Serial data 7.908389 8.25E-05 0x7D
Async Serial data 7.908476 8.25E-05 0x22
Async Serial data 7.908562 8.25E-05 0xD3
Async Serial data 7.908649 8.25E-05 0xDE
Async Serial data 7.908736 8.25E-05 0x7E end first received ppp packet
Async Serial [1] data 7.913322 8.25E-05 0xFF second ppp packet sent by STM,
why is the 0x7E byte ommitted? I also attached debugger to get data bytes
provided by LWIP, first byte is -0xFF
Async Serial [1] data 7.91341 8.25E-05 0x7D
Async Serial [1] data 7.913498 8.25E-05 0x23
Async Serial [1] data 7.913586 8.25E-05 0xC0
Async Serial [1] data 7.913674 8.25E-05 0x21
Async Serial [1] data 7.913762 8.25E-05 0x7D
Async Serial [1] data 7.91385 8.25E-05 0x24
Async Serial [1] data 7.913938 8.25E-05 0xE5
Async Serial [1] data 7.914026 8.25E-05 0x7D
Async Serial [1] data 7.914114 8.25E-05 0x20
Async Serial [1] data 7.914202 8.25E-05 0x7D
Async Serial [1] data 7.91429 8.25E-05 0x29
Async Serial [1] data 7.914378 8.25E-05 0x7D
Async Serial [1] data 7.914466 8.25E-05 0x23
Async Serial [1] data 7.914554 8.25E-05 0x7D
Async Serial [1] data 7.914642 8.25E-05 0x25
Async Serial [1] data 7.91473 8.25E-05 0xC2
Async Serial [1] data 7.914818 8.25E-05 0x23
Async Serial [1] data 7.914906 8.25E-05 0x7D
Async Serial [1] data 7.914994 8.25E-05 0x25
Async Serial [1] data 7.915082 8.25E-05 0x7A
Async Serial [1] data 7.91517 8.25E-05 0xEF
Async Serial [1] data 7.915258 8.25E-05 0x7E
Async Serial data 7.915929 8.25E-05 0x7E
Async Serial data 7.916016 8.25E-05 0xFF
Async Serial data 7.916102 8.25E-05 0x7D
Async Serial data 7.916189 8.25E-05 0x23
Async Serial data 7.916276 8.25E-05 0xC0
Async Serial data 7.916363 8.25E-05 0x21
Async Serial data 7.91645 8.25E-05 0x7D
Async Serial data 7.916536 8.25E-05 0x21
Async Serial data 7.916623 8.25E-05 0xE6
Async Serial data 7.91671 8.25E-05 0x7D
Async Serial data 7.916797 8.25E-05 0x20
Async Serial data 7.916884 8.25E-05 0x7D
Async Serial data 7.916971 8.25E-05 0x34
Async Serial data 7.917057 8.25E-05 0x7D
Async Serial data 7.917144 8.25E-05 0x22
Async Serial data 7.917231 8.25E-05 0x7D
Async Serial data 7.917318 8.25E-05 0x26
Async Serial data 7.917405 8.25E-05 0x7D
Async Serial data 7.917491 8.25E-05 0x20
Async Serial data 7.917578 8.25E-05 0x7D
Async Serial data 7.917665 8.25E-05 0x20
Async Serial data 7.917752 8.25E-05 0x7D
Async Serial data 7.917839 8.25E-05 0x20
Async Serial data 7.917925 8.25E-05 0x7D
Async Serial data 7.918012 8.25E-05 0x20
Async Serial data 7.918099 8.25E-05 0x7D
Async Serial data 7.918186 8.25E-05 0x25
Async Serial data 7.918273 8.25E-05 0x7D
Async Serial data 7.918359 8.25E-05 0x26
Async Serial data 7.918446 8.25E-05 0x26
Async Serial data 7.918533 8.25E-05 0xA6
Async Serial data 7.91862 8.25E-05 0x32
Async Serial data 7.918707 8.25E-05 0x2F
Async Serial data 7.918793 8.25E-05 0x7D
Async Serial data 7.91888 8.25E-05 0x27
Async Serial data 7.918967 8.25E-05 0x7D
Async Serial data 7.919054 8.25E-05 0x22
Async Serial data 7.919141 8.25E-05 0x7D
Async Serial data 7.919227 8.25E-05 0x28
Async Serial data 7.919314 8.25E-05 0x7D
Async Serial data 7.919401 8.25E-05 0x22
Async Serial data 7.919488 8.25E-05 0x46
Async Serial data 7.919575 8.25E-05 0xDA
Async Serial data 7.919661 8.25E-05 0x7E
Async Serial [1] data 7.9253 8.25E-05 0xFF
Async Serial [1] data 7.925388 8.25E-05 0x7D
Async Serial [1] data 7.925476 8.25E-05 0x23
Async Serial [1] data 7.925564 8.25E-05 0xC0
Async Serial [1] data 7.925652 8.25E-05 0x21
Async Serial [1] data 7.92574 8.25E-05 0x7D
Async Serial [1] data 7.925828 8.25E-05 0x22
Async Serial [1] data 7.925916 8.25E-05 0xE6
Async Serial [1] data 7.926004 8.25E-05 0x7D
Async Serial [1] data 7.926092 8.25E-05 0x20
Async Serial [1] data 7.92618 8.25E-05 0x7D
Async Serial [1] data 7.926268 8.25E-05 0x34
Async Serial [1] data 7.926356 8.25E-05 0x7D
Async Serial [1] data 7.926444 8.25E-05 0x22
Async Serial [1] data 7.926532 8.25E-05 0x7D
Async Serial [1] data 7.92662 8.25E-05 0x26
Async Serial [1] data 7.926708 8.25E-05 0x7D
Async Serial [1] data 7.926796 8.25E-05 0x20
Async Serial [1] data 7.926884 8.25E-05 0x7D
Async Serial [1] data 7.926972 8.25E-05 0x20
Async Serial [1] data 7.92706 8.25E-05 0x7D
Async Serial [1] data 7.927149 8.25E-05 0x20
Async Serial [1] data 7.927237 8.25E-05 0x7D
Async Serial [1] data 7.927325 8.25E-05 0x20
Async Serial [1] data 7.927413 8.25E-05 0x7D
Async Serial [1] data 7.927501 8.25E-05 0x25
Async Serial [1] data 7.927589 8.25E-05 0x7D
Async Serial [1] data 7.927677 8.25E-05 0x26
Async Serial [1] data 7.927765 8.25E-05 0x26
Async Serial [1] data 7.927853 8.25E-05 0xA6
Async Serial [1] data 7.927941 8.25E-05 0x32
Async Serial [1] data 7.928029 8.25E-05 0x2F
Async Serial [1] data 7.928117 8.25E-05 0x7D
Async Serial [1] data 7.928205 8.25E-05 0x27
Async Serial [1] data 7.928293 8.25E-05 0x7D
Async Serial [1] data 7.928381 8.25E-05 0x22
Async Serial [1] data 7.928469 8.25E-05 0x7D
Async Serial [1] data 7.928557 8.25E-05 0x28
Async Serial [1] data 7.928645 8.25E-05 0x7D
Async Serial [1] data 7.928733 8.25E-05 0x22
Async Serial [1] data 7.928821 8.25E-05 0xAD
Async Serial [1] data 7.928909 8.25E-05 0xB3
Async Serial [1] data 7.928997 8.25E-05 0x7E
Async Serial [1] data 7.929411 8.25E-05 0xFF
Async Serial [1] data 7.929499 8.25E-05 0x03
Async Serial [1] data 7.929587 8.25E-05 0x80
Async Serial data 7.929658 8.25E-05 0x7E
Async Serial [1] data 7.929675 8.25E-05 0x21
Async Serial data 7.929744 8.25E-05 0xFF
Async Serial [1] data 7.929763 8.25E-05 0x01
Async Serial data 7.929831 8.25E-05 0x7D
Async Serial [1] data 7.929851 8.25E-05 0x01
Async Serial data 7.929918 8.25E-05 0x23
Async Serial [1] data 7.929939 8.25E-05 0x00
Async Serial data 7.930005 8.25E-05 0xC0
Async Serial [1] data 7.930027 8.25E-05 0x0A
Async Serial data 7.930092 8.25E-05 0x21
Async Serial [1] data 7.930115 8.25E-05 0x03
Async Serial data 7.930178 8.25E-05 0x7D
Async Serial [1] data 7.930203 8.25E-05 0x06
Async Serial data 7.930265 8.25E-05 0x2B
Async Serial [1] data 7.930291 8.25E-05 0x00
Async Serial data 7.930352 8.25E-05 0xE7
Async Serial [1] data 7.930379 8.25E-05 0x00
Async Serial data 7.930439 8.25E-05 0x7D
Async Serial [1] data 7.930467 8.25E-05 0x00
Async Serial data 7.930526 8.25E-05 0x20
Async Serial [1] data 7.930555 8.25E-05 0x00
Async Serial data 7.930612 8.25E-05 0x7D
Async Serial data 7.930699 8.25E-05 0x28
Async Serial data 7.930786 8.25E-05 0x26
Async Serial data 7.930873 8.25E-05 0xA6
Async Serial data 7.93096 8.25E-05 0x32
Async Serial data 7.931046 8.25E-05 0x2F
Async Serial data 7.931133 8.25E-05 0x74
Async Serial data 7.93122 8.25E-05 0xC1
Async Serial data 7.931307 8.25E-05 0x7E
Async Serial [1] data 7.931541 8.25E-05 0x13
Async Serial [1] data 7.931629 8.25E-05 0x28
Async Serial [1] data 7.931717 8.25E-05 0x7E
Async Serial data 7.93236 8.25E-05 0x7E
Async Serial data 7.932447 8.25E-05 0x80
Async Serial data 7.932534 8.25E-05 0x21
Async Serial data 7.93262 8.25E-05 0x01
Async Serial data 7.932707 8.25E-05 0xFD
Async Serial data 7.932794 8.25E-05 0x00
Async Serial data 7.932881 8.25E-05 0x04
Async Serial data 7.932968 8.25E-05 0x2C
Async Serial data 7.933054 8.25E-05 0xB0
Async Serial data 7.933141 8.25E-05 0x7E
Async Serial data 7.933228 8.25E-05 0x7E
Async Serial data 7.933315 8.25E-05 0x80
Async Serial data 7.933402 8.25E-05 0x21
Async Serial data 7.933488 8.25E-05 0x03
Async Serial data 7.933575 8.25E-05 0x01
Async Serial data 7.933662 8.25E-05 0x00
Async Serial data 7.933749 8.25E-05 0x0A
Async Serial data 7.933836 8.25E-05 0x03
Async Serial data 7.933922 8.25E-05 0x06
Async Serial data 7.934009 8.25E-05 0x0A
Async Serial data 7.934096 8.25E-05 0x81
Async Serial data 7.934183 8.25E-05 0x4B
Async Serial data 7.93427 8.25E-05 0x67
Async Serial data 7.934356 8.25E-05 0xCA
Async Serial data 7.934443 8.25E-05 0xA1
Async Serial data 7.93453 8.25E-05 0x7E
Async Serial [1] data 7.939163 8.25E-05 0xFF
Async Serial [1] data 7.939251 8.25E-05 0x03
Async Serial [1] data 7.939339 8.25E-05 0x80
Async Serial [1] data 7.939427 8.25E-05 0x21
Async Serial [1] data 7.939515 8.25E-05 0x03
Async Serial [1] data 7.939603 8.25E-05 0xFD
Async Serial [1] data 7.939691 8.25E-05 0x00
Async Serial [1] data 7.939779 8.25E-05 0x0A
Async Serial [1] data 7.939867 8.25E-05 0x03
Async Serial [1] data 7.939955 8.25E-05 0x06
Async Serial [1] data 7.940043 8.25E-05 0x00
Async Serial [1] data 7.940131 8.25E-05 0x00
Async Serial [1] data 7.940219 8.25E-05 0x00
Async Serial [1] data 7.940307 8.25E-05 0x00
Async Serial [1] data 7.940395 8.25E-05 0x6B
Async Serial [1] data 7.940483 8.25E-05 0x1A
Async Serial [1] data 7.940571 8.25E-05 0x7E
Async Serial [1] data 7.941107 8.25E-05 0xFF
Async Serial [1] data 7.941195 8.25E-05 0x03
Async Serial data 7.9412 8.25E-05 0x7E
Async Serial [1] data 7.941283 8.25E-05 0x80
Async Serial data 7.941287 8.25E-05 0x80
Async Serial [1] data 7.941371 8.25E-05 0x21
Async Serial data 7.941374 8.25E-05 0x21
Async Serial [1] data 7.94146 8.25E-05 0x01
Async Serial data 7.94146 8.25E-05 0x01
Async Serial data 7.941547 8.25E-05 0xFE
Async Serial [1] data 7.941548 8.25E-05 0x02
Async Serial data 7.941634 8.25E-05 0x00
Async Serial [1] data 7.941636 8.25E-05 0x00
Async Serial data 7.941721 8.25E-05 0x04
Async Serial data 7.941808 8.25E-05 0x48
Async Serial data 7.941894 8.25E-05 0x5F
Async Serial data 7.941981 8.25E-05 0x7E
Async Serial [1] data 7.942683 8.25E-05 0x0A
Async Serial [1] data 7.942771 8.25E-05 0x03
Async Serial [1] data 7.942859 8.25E-05 0x06
Async Serial [1] data 7.942947 8.25E-05 0x0A
Async Serial [1] data 7.943035 8.25E-05 0x81
Async Serial [1] data 7.943123 8.25E-05 0x4B
Async Serial [1] data 7.943211 8.25E-05 0x67
Async Serial [1] data 7.943299 8.25E-05 0xFD
Async Serial [1] data 7.943387 8.25E-05 0xC1
Async Serial [1] data 7.943475 8.25E-05 0x7E
Async Serial data 7.944092 8.25E-05 0x7E
Async Serial data 7.944178 8.25E-05 0x80
Async Serial data 7.944265 8.25E-05 0x21
Async Serial data 7.944352 8.25E-05 0x02
Async Serial data 7.944439 8.25E-05 0x02
Async Serial data 7.944526 8.25E-05 0x00
Async Serial data 7.944612 8.25E-05 0x0A
Async Serial data 7.944699 8.25E-05 0x03
Async Serial data 7.944786 8.25E-05 0x06
Async Serial data 7.944873 8.25E-05 0x0A
Async Serial data 7.94496 8.25E-05 0x81
Async Serial data 7.945046 8.25E-05 0x4B
Async Serial data 7.945133 8.25E-05 0x67
Async Serial data 7.94522 8.25E-05 0xEA
Async Serial data 7.945307 8.25E-05 0x5B
Async Serial data 7.945394 8.25E-05 0x7E
Async Serial [1] data 7.949159 8.25E-05 0xFF
Async Serial [1] data 7.949247 8.25E-05 0x03
Async Serial [1] data 7.949335 8.25E-05 0x80
Async Serial [1] data 7.949423 8.25E-05 0x21
Async Serial [1] data 7.949511 8.25E-05 0x02
Async Serial [1] data 7.949599 8.25E-05 0xFE
Async Serial [1] data 7.949687 8.25E-05 0x00
Async Serial [1] data 7.949775 8.25E-05 0x04
Async Serial [1] data 7.949863 8.25E-05 0x3E
Async Serial [1] data 7.949951 8.25E-05 0x54
Async Serial [1] data 7.950039 8.25E-05 0x7E
Op ma 7 jun. 2021 om 16:19 schreef Bas Prins <bas.prins3@gmail.com>:
> Dear,
>
> I was looking at the data being sent/received over uart when ppp is being
> negotiated. I was surprised to see that the received byte stream is always
> wrapped in 0x7e bytes (leading + trailing).
>
> But for some reason this is not the case for the bytes lwip sends
> (/provides to my sio_write function). Even stronger, sometimes it does
> start with a leading 0x7e, sometimes it doesn't.
>
> On the wiki I read:
>
> "PPP packets all start and end with 0x7E. If you don't see these,
> something is wrong with your low level driver"
>
> When I look at fsm.c where the PPP header is created, I don't see 0x7e
> being added as part of the opening header.
>
> pppos works, lwip works, I can open sockets, download from FTP, etc. So
> what's the deal with this? Should I investigate further and is there a bug
> sitting in my code? Or is this "perfectly normal" behavior and is the wiki
> wrong?
>
> I added the logic analyzer export to this email.
>
> Hopefully someone can shed some light on this.
>
> best regards, bas
>
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.nongnu.org/archive/html/lwip-users/attachments/20210607/656bf652/attachment.html>
------------------------------
Subject: Digest Footer
_______________________________________________
lwip-users mailing list
lwip-users@nongnu.org
https://lists.nongnu.org/mailman/listinfo/lwip-users
------------------------------
End of lwip-users Digest, Vol 214, Issue 4
******************************************
| [Prev in Thread] | Current Thread | [Next in Thread] |