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OK, I've got a new idea: CAN timing.<br>
<br>
Comparing our esp32can bit timing to the esp-idf driver's, there
seem to be some differences:<br>
<a class="moz-txt-link-freetext" href="https://github.com/espressif/esp-idf/blob/master/components/hal/include/hal/twai_types_deprecated.h#L75">https://github.com/espressif/esp-idf/blob/master/components/hal/include/hal/twai_types_deprecated.h#L75</a><br>
<br>
Transceivers are normally tolerant to small timing offsets. Maybe
being off a little bit has no effect under normal conditions, but it
has when the transceiver has to cope with a filled RX queue. That
could be causing the transceiver to slide just out of sync. If the
timing gets garbled, the transceiver would signal errors in the
packets to the bus, possibly so many the vehicle ECUs decide to
raise an error condition.<br>
<br>
Is that plausible?<br>
<br>
On why the new poller could be causing this (in combination with too
slow processing by the vehicle): as mentioned, the standard CAN
listener mechanism doesn't care about queue overflows. The poller
does. `OvmsPollers::Queue_PollerFrame()` does a log call when Tx/Rx
tracing is enabled, that could even block, but tracing is optional
and only meant for debugging. Not optional is the overflow counting
using an atomic uint32.<br>
<br>
The atomic types are said to be fast, but I never checked their
actual implementation on the ESP32. Maybe they can block as well?<br>
<br>
@Simon: it would be an option to try commenting out the overflow
counting, to see if that's causing the issue.<br>
<br>
Regards,<br>
Michael<br>
<br>
<br>
<div class="moz-cite-prefix">Am 17.01.25 um 15:37 schrieb Chris Box
via OvmsDev:<br>
</div>
<blockquote type="cite"
cite="mid:010b019474b30c0d-45366923-5cdc-4a4b-a59d-cedf24ac5d5d-000000@eu-west-2.amazonses.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Yes, I can confirm I've had one experience of the Leaf
switching to Neutral while driving, with a yellow warning symbol
on the dash. It refused to reselect Drive until I had switched
the car off and back on. Derek wasn't so lucky and he need to
clear fault codes before the car would work.</p>
<p>On returning home, I found OVMS was not accessible over a
network. I didn't try a USB cable. Unplugging and reinserting
the OBD cable caused OVMS to rejoin Wi-Fi. However the SD logs
showed nothing from the time of the event. CAN writes are
enabled, so it can perform SOC limiting.</p>
<p>My car has been using this firmware since 21st November, based
on the git master of that day. As a relatively new user of OVMS
(only since October) I don't have much experience of older
firmware.</p>
<p>Perhaps a safeguard should be implemented before releasing a
new stable firmware that will be automatically downloaded by
Leaf owners. But I don't have the expertise to know what that
safeguard should be. Derek's suggestion of 'only CAN write when
parked' appears to be a good idea.</p>
<p>Chris</p>
<p><br>
</p>
<p id="reply-intro">On 2025-01-15 18:18, Derek Caudwell via
OvmsDev wrote:</p>
<blockquote type="cite"
style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">
<div id="replybody1">
<div dir="auto">Since the following email I have high
confidence the issue on the Leaf is related/caused by the
poller as there has been no further occurrence and Chris has
also experienced the car going to neutral on the new poller
firmware.
<div dir="auto"><br>
<div dir="auto">....</div>
<div dir="auto">I haven't ruled out it being a fault with
my car yet. Shortly after it faulted the car was run
into so has been off the road for sometime, my first
step was to replace 12V battery. The ovms unit is now
unplugged and if it does not fault over the next month
while driving I'll be reasonably confident it's ovms
related.</div>
<div dir="auto"> </div>
<div dir="auto">Not sure which firmware version the poller
updates were included in but it was only after upgrading
to it that the errors occurred (which could be
coincidental however it has faulted twice more both on
version 3.3.004-141-gf729d82c). For periods where I
reverted to 3.3.003 it was fine.</div>
<div dir="auto"> </div>
<div dir="auto">It might be useful to have an extra option
on the enable can write to only enable it when the car
is parked/charging.</div>
</div>
</div>
<br>
<div class="v1gmail_quote v1gmail_quote_container"> </div>
</div>
</blockquote>
<p><br>
</p>
<br>
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Michael Balzer * Am Rahmen 5 * D-58313 Herdecke
Fon 02330 9104094 * Handy 0176 20698926</pre>
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