CH340/CH341 USB to RS232 not working

serguzest · November 22, 2018 at 9:15 PM

Hi,

I bought a USB to RS232 converter to control my marantz amp via rpi3.

It works with fedora but not working with libreelec(tried with 8.2.5 and latest version) or raspbian.

Anyone have idea?

uname -a:

Linux uurMedia 4.19.3 #1 SMP Wed Nov 21 22:15:07 GMT 2018 armv7l GNU/Linux

dmesg:

[ 5.408909] usbcore: registered new interface driver usbserial_generic

[ 5.408955] usbserial: USB Serial support registered for generic

[ 5.515329] usbcore: registered new interface driver ch341

[ 5.515383] usbserial: USB Serial support registered for ch341-uart

[ 5.515471] ch341 1-1.2:1.0: ch341-uart converter detected

[ 5.519709] usb 1-1.2: ch341-uart converter now attached to ttyUSB0

lsusb output:

Bus 001 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter

Thanks

**Iridium** · November 23, 2018 at 5:42 PM Official Post

1) Which version of Fedora did you use arm7 or aarm64?

2) How do you use it in Fedora when it is working?

3) Post output of lsmod

Please provide a full debug log.

How to post a log (wiki)

1. Enable debugging in Settings>System Settings>Logging
2. Restart Kodi
3. Replicate the problem
4. Generate a log URL (do not post/upload logs to the forum)

use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link

**Da Flex** · November 23, 2018 at 9:26 PM Official Post

Quote from serguzest

I bought a USB to RS232 converter to control my marantz amp via rpi3.

Don't do this. You will run into USB driver issues on RPi3. Use a TTL-to-RS232 converter (at GPIO RX/TX). It's cheap, and you will find a lot of manuals how to connect and test that converter. There are small versions that you can mount in your RPi3 case.

serguzest · November 24, 2018 at 2:47 PM

Suddenly it's started to work :S, i am not sure what was the problem.

But most of the time i need to send same command few times to work.

**Da Flex** · November 24, 2018 at 3:03 PM Official Post

Quote from serguzest

Suddenly it's started to work :S, i am not sure what was the problem.

But most of the time i need to send same command few times to work.

See, that's why. You will have a stable connection, if you follow my suggestion.

serguzest · November 24, 2018 at 3:25 PM

are you suggesting pl 2023 chip?

please give me a link at least please.

**Da Flex** · November 24, 2018 at 4:00 PM Official Post

Quote from serguzest

are you suggesting pl 2023 chip?

please give me a link at least please.

This is what I bought at Amazon Germany: TTL-to-RS232 converter

**Da Flex** · November 24, 2018 at 4:39 PM Official Post

PS: You will need some fe-ma-le cables, too, to connect to GPIO: 40 fe-ma-le cables

(had to split a word, because it's censored - funny)

**vpeter** · November 24, 2018 at 9:10 PM

Quote from Da Flex

(had to split a word, because it's censored - funny)

Use "bitch cables" then

PackElend · December 18, 2022 at 7:38 PM

For anyone who is trying to control externals via RS232 (I'm about, to begin with, it), the Delock Products 62960 Delock Adapter USB 2.0 Type-A > 1 x Serial RS-232 RJ45 1.8 m is detected well.

The following is just for your information, if someone has to go through logs and needs some reference

Code

====================== Kernel Message Log ===================
LibreELEC:~ # dmesg
[    2.243580] usb 1-1.4: new full-speed USB device number 3 using xhci_hcd
[    2.349864] usb 1-1.4: New USB device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
[    2.349878] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.349889] usb 1-1.4: Product: FT232R USB UART
[    2.349900] usb 1-1.4: Manufacturer: FTDI
[    2.349910] usb 1-1.4: SerialNumber: A10K5SV4
...
[    5.085449] usbcore: registered new interface driver usbserial_generic
[    5.085474] usbserial: USB Serial support registered for generic
[    5.087747] usbcore: registered new interface driver ftdi_sio
[    5.087783] usbserial: USB Serial support registered for FTDI USB Serial Device
[    5.087857] ftdi_sio 1-1.4:1.0: FTDI USB Serial Device converter detected
[    5.087921] usb 1-1.4: Detected FT232RL
[    5.098474] usb 1-1.4: FTDI USB Serial Device converter now attached to ttyUSB0

Display More

Code

LibreELEC:~ # lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0403:6001 Future Technology Devices International, Ltd FT232 Serial (UART) IC
Bus 001 Device 014: ID 0d8c:0102 C-Media Electronics, Inc. CM106 Like Sound Device
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub