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

[tu...@posteo.de]

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

[R0b0t1]

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.

[tu...@posteo.de]

Hi R0b0t1,

:) thank you very much for your reply! :)

Since it will become nevertheless more Android loaden I will
respond off list ...

Cheers
Meino

[tu...@posteo.de]

Sorry...not "ANDROID loaden"...it should be "ARDUINO" loaden...
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