Re: [gentoo-user] Struggling with CH340 serial<=>USB converter (Arduino related)

[R0b0t1]

On Tue, Jul 25, 2017 at 12:17 PM,  <tuxic@××××××.de> wrote:
> Hi,
>
> (yes, I also have a FTDI USB<=>serial adapter...in this case I need to
> get my CH340 based work)
>
> this drives me crazy...
>
> My CH340G USB<=>serial adaptor is recognized as
> (lsusb)
> Bus 007 Device 011: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter
> (dmesg)
> [52255.016438] usb 7-4: new full-speed USB device number 11 using ohci-pci
> [52255.167432] usb 7-4: New USB device found, idVendor=1a86, idProduct=7523
> [52255.167439] usb 7-4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
> [52255.167443] usb 7-4: Product: USB2.0-Serial
> [52255.169580] ch341 7-4:1.0: ch341-uart converter detected
> [52255.179543] usb 7-4: ch341-uart converter now attached to ttyUSB3
>
>
> But that's it.
>
> It does not seem to react on any kind of action I try to achieve with
> avrdude (I skipped the arduino IDE to get one variable off this
> eqyitation...).
>
> I instructed avrdude to "speak to the board" like this:
> avrdude -p ATmega2560 -c arduino -P /dev/ttyUSB3 -b 9600
>
> ...but the only reaction I get is ...timeouts...
>
> I have no clue what to do next.
>
> How can I devide the things which are working so far from those
> which are not working.
>
> The ATmega2560 board is working - I can flash it via buspirate (ICSP).
> I burned a bootloader with that...just to mention...not wanting to
> start an Arduino discussion on a Gentoo mailinglist...only to
> explain the context a little bit...
>
> What is the status of the ch340/ch341 driver?
> (I am running kernel 4.12.3 vanilla right off Linus desktop so to
> say...)
>
> Thanks a lot for any help in advance!
> Cheers
> Meino
>

If the device creates a /dev node there is probably no issue with the
driver. The default Arduino speed is now 57,600, are you sure 9,600 is
right? Before that it was 38,400. Use the ICSP interface to flash a
program that prints things via serial and see if you can receive them.
If your serial connection is unreliable you will get garbled
characters.

Avrdude should eventually time out with a message, what is that message?

I have been experiencing similar problems that you have described with
various Arduino and Arduino-derived boards and so far have not been
able to explain it. Most of the time they work perfectly but some do
not and the bootloader seems to refuse to work.

R0b0t1.