usb to serial adapter -> /dev/ttyUSB0

Question

Hi

I have attached my weather 2305 station to an USB-Serial adapter Prolific 2303. The adapter is correctly recognized by OS (Linux Ubuntu 5.10 - kernel 2.6.10 and the device /dev/ttyUSB0 is created. I compiled open2300 configuring in the open2300-dist.conf file the correct serial port /dev/ttyUSB0. When I launch open2300 I have this error message: Unable to initialize serial device Is the usb to serial converter unsupported ? Is the /dev/ttyUSBx device unsupported ?

Regards emanuel

Environment

Open2300 version:	1.10
Libraries:	mysql, postgresql
Server OS:	linux ubuntu 5.10 - 2.6.10

-- EmanuelMonticelli - 01 Oct 2006

Answer

For the WS23XX weather stations you have to be able to control the control lines of the RS232 port in a non standard way. My guess is that the USB/RS232 adapter does not support this.

-- KennethLavrsen - 22 Oct 2006

Details

It's quite strange because if I use the same usb/rs232 converter under windowsXP the official SW of WS23XX works perfectly. So, it could be not a problem related to the hw usb/rs232 converter. So, what tests can I do to try to solve the problem ? Any suggestions ?

-- EmanuelMonticelli - 11 Dec 2006

You may find that you need to change the permissions on the device so that you can read/write - this is common for usb devices

Now Working with USB/Serial Adapter

I have upgraded my ubuntu distribution to 6.06 release and now it's working. Why ???? I do not know. My configuration is Ubuntu 6.06 - USBtoSerial Converter based on prolific 2303 chipset and LaCrosse WS2305 and obviously Open2300. I am now working on the crosscompiling of Open2300 on the Axis Etrax LX chip and development board.

-- EmanuelMonticelli - 04 Jan 2007

Insights

Emanuel,

Based on my experience with other devices that rely on the Prolific 2303 chipset I'm surprised you got this working at all. Devices that use that driver have the capability to receive characters, but fail to transmit anything. I can only guess that your update to your O/S brought in an update/repaired version of this driver that finally resolves the issue. Since other distros may not have yet picked up this fix, I would not recommend using such a device to anyone reading this question. I have successfully used the Siig USB-to-Serial adapter on SuSe (nld9) and FC6 distros. My own weather station is connected to my FC6 based system by the Siig device. I make no representations however that this device will work with any particular hardware/distro configuration. Your mileage may vary.