Re: going beyond a ch341 uart-usb convertor
On Monday 12 April 2021 05:29:42 Christian Seiler wrote:
> Hi there,
>
> Am 2021-04-12 05:55, schrieb Gene Heskett:
> > Building a design/builder for a 3d printer, which when a std usb to
> > printer cable is connected between the computer and the 3d printer,
> > Identifies as a ch341 convertor cable once it is plugged into the
> > printer.
> >
> > [...]
> >
> > What would the next thing to try and discover why its not working?
>
> Do you actually have permissions for the device? Typically serial
> devices have permissions such that only root and the group 'dialout'
> can access them. You can check that via:
>
> ls -l /dev/ttyUSB0
>
> That will typically look something like
>
> crw-rw---- 1 root dialout 4, 64 Apr 12 08:54 /dev/ttyUSB0
>
> You can use id to determine if you are in the 'dialout' group. If
> that doesn't appear (but your user and other groups do appear), then
> you may add your user to that group via
>
> gpasswd -a USERNAME dialout
>
> (Replace USERNAME by your username, run this command as root.)
>
> (Note that I've used ttyUSB0 here, because CH341 devices typically
> appear as such, but other USB to serial converters may also appear
> as ttyACM0 instead of ttyUSB0.)
>
> Additionally, even if the permissions are OK, if you have ModemManager
> installed (which is typically the case on desktop systems), for the
> first 30 to 60 seconds it will try to detect if the device in question
> is a model, and only once that fails will it release the device. So it
> could be that the device is "stolen" by ModemManager directly after
> pluggin it in and/or powering it up, and you have to wait a bit until
> ModemManager releases it.
>
> Furthermore, if you have software installed that is used for devices
> that help people with vision impairments, it could be that that
> interferes with USB serial devices, as some such devices also use a
> USB serial interface.
>
> You can check if another software (ModemManager, or something else) is
> currently using the serial device by calling:
>
> lsof /dev/ttyUSB0
>
> (Run the command as root.)
>
> Hope that helps!
Maybe. Since I am a C.E.T., I took the bottom off, finding an apparently
well regarded 32 bit board by Makerbase, a Robin MKS Nano V1.2
Carefull inspection seems to indicate a lot of heat telegraphed out of
one of the 4 pwr transistors adjacent to where the bed heater wires are
attached. And since it heats the bed first, nothing else but homing
works. Since I've $400 with taxes in this thing, and it has a BIQU H2
printhead, which I can get steel nozzles for, and I just ordered 2 rolls
of carbon fiber reenforced PETG for my ender 3 with a fixed microswiss
extruder kit with steel nozzles, I have ordered the whole kit, touch
display and interconnect cable and everything to replace it with. Around
$75. Maybe I can salvage it yet.
But it will be the middle of May arriving. Same as the H2 I have coming
for the ender 3. The ender 3 can be picky, but I have the dregs of the
6th roll of PETG on its peg right now. Considering PETG is the topend of
its temps range, surviving for 6 rolls is great.
Thanks Christian, stay well now.
> Regards,
> Christian
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>
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