[Dreamplug] Getting FTDI-Converters to work

[Note]:  Equipment is Dreamplug with NewIT-2.6.?-dirty Kernel, installed Debian 6.0 (NewIT-Edition) and Mono 2.10 / Apache 2 installed.

Currently I'm desperately working on getting an FTDI-USB-to-RS485-Converter operating on my Dreamplugs (using Debian 6.0).

I found out NewIT-Dreamplug-Kernel is not supporting USB-Serial Converters, so I have to find alternatives where these modules are included or compileable.

I stumbled upon  http://sheeva.with-linux.com/, where a myriad of kernels is located.

The Author was so kind as to supply a shellscript doing all the work for you.

Just download the Script from the Website using wget and make it executable

  root@debian:~# wget http://sheeva.with-linux.com/sheeva/README-DREAM-UPDATE.sh  
  root@debian:~# chmod 777 README-DREAM-UPDATE.sh  

Afterwards you just have to execute the Shellscript and giving the desired kernel Version as a parameter

  ./README-DREAM-UPDATE.sh 3.3.4  

The update process terminates with the following lines:

 Extracting modules  
 Writing kernel to /boot  
 ****************************************************************  
  update your bootcmd to load dream-3.3.4-uImage  
  or create a link from /boot/dream-3.3.4-uImage to /boot/uImage  
 ****************************************************************  

I ignored that hints and attached my bootable Ubuntu-Stick (9.04 dreamplug version), i usually use for updates, and copied the content from /boot to the stick's /home folder after mounting.

 mount /dev/sdc2 /mnt/dp_system  
 cd dp_system/home  
 cp -r /boot ./  
 cd /  
 sync  
 umount /dev/sdc2  

Afterwards I booted from this USB-Stick (don't forget to change uBoot Environment accordingly) and copied the new uImage and sheeva-sysfile to /dev/sda1 (fat16 file system of internal SD)

See also: http://semicolon-expected.blogspot.com/2012/04/dreamplug-backup-your-system-from.html

After successful reboot from freshly updated internal SD you could run uname -a command and should see your new kernel version number.

 root@debian:~# uname -a  
 Linux debian 3.3.4 #1 PREEMPT Fri Apr 27 16:11:35 MDT 2012 armv5tel GNU/Linux  

Because this kernel comes with serial-usb-converter modules  you simply can plug in your FTDI-Chip and you should get some output like that

 root@debian:~# usb 1-1.3: new full-speed USB device number 6 using orion-ehci  
 ftdi_sio 1-1.3:1.0: FTDI USB Serial Device converter detected  
 usb 1-1.3: Detected FT232RL  
 usb 1-1.3: Number of endpoints 2  
 usb 1-1.3: Endpoint 1 MaxPacketSize 64  
 usb 1-1.3: Endpoint 2 MaxPacketSize 64  
 usb 1-1.3: Setting MaxPacketSize 64  
 usb 1-1.3: FTDI USB Serial Device converter now attached to ttyUSB0  

If not, run the following command (which "enables" the ftdi_sio module manually)

 root@debian:~# modprobe ftdi_sio  
 usbcore: registered new interface driver usbserial  
 USB Serial support registered for generic  
 usbcore: registered new interface driver usbserial_generic  
 usbserial: USB Serial Driver core  
 USB Serial support registered for FTDI USB Serial Device  
 usbcore: registered new interface driver ftdi_sio  
 ftdi_sio: v1.6.0:USB FTDI Serial Converters Driver  

You may then finally test the command and send out something (1st command) and/or read the response (second command)

 root@debian:~# echo "hello world!" > /dev/ttyUSB0  
 root@debian:~# tail -f /dev/ttyUSB0