gps (usb-serial)

[michaelkj77]

I can't get TC to recognize either my Delorme LT-20 or my other generic puck-style usb gps receiver.  When I plug in the gps and look at dmesg, I see:

"usb 3-2: new full speed USB device using uhci_hcd and address 2"

I can't find a device in /dev that this maps to.  Not sure what to tell any applications that use the gps what device to use.  I see several gpsd packages in the repository.  Will one of those map a gps on a usb port to a device in /dev?

Thanks

[danielibarnes]

For Tiny Core 3.x, make sure you have usb-serial-2.6.33.3-tinycore.tcz loaded. It will typically create /dev/ttyUSB0.

[michaelkj77]

The usb-serial-2.6.33.3-tinycore.tcz package worked perfectly.  Tiny Core now recoginzes both my Delorme LT-20 which uses the cypress-m8 driver and my generic puck gps which uses the Prolific PL2303 driver.  I had yet to find a small linux distro that supported either.  Excellent assistance.  Greatly appreciated.

Thanks.

[michaelkj77]

Dang, I have to back track a bit.  The usb-serial-2.6.33.3-tinycore.tcz suggestion worked on my netbook where I had booted from a CD and downloaded the tcz file with the apps tool.  I saved the .tcz file to my compact flash however in the /tce/options directory.  I have another computer that boots from the compact flash and seems to load the usb-serial....tcz file.  That file is included in the onboot.lst file.  I can find it in /usr/local/tce.installed/ and /tmp/tcloop/.  However from the other computer, neither of the GPS receivers are recognized or assigned a device like ttyUSB0.  I've waited to plug in the devices until after the OS loads hoping that they would be recognized and assigned a device, but that didn't work.  Not sure why the gps receivers are assigned a device on the netbook but not on the other computer.  By the way, the other computer won't have an internet connection.  It is a little 12-volt industrial computer that will be running in a vehicle so the tcz packages have to install from the compact flash.  One other application, Xastir does install that way so I think I have that set up correctly.  Any advice appreciated. 

[maro]

If you have double checked that both your systems are loading the same (relevant) set of extensions, I'd suspect the device recognition does not come to the same result on those two different systems.

I'd suggest you produce the output of the dmesg command and carefully look for the differences as far as 'USB' related entries are concerned (in the worst case: produce two attachements here and one of us might take a look, but please try it first yourself).

[michaelkj77]

Very good advice.  I will check as you suggested.  I did find one difference which appears to be the cause, but not sure why this happened.  On the netbook where the gps devices work, the usb-serial-.6.33.3-tinycore.tcz package has loaded soft links in /sys/module/usbserial/drivers which point to /sys/module/bus/usb/drivers/generic, .../usbserial, and .../usbserial_generic.  There are drivers for the cypress_m8 (Delorme), the PL2303, and another generic gps receiver.  None of that exists on the other computer booting from the compact flash. 

[maro]

I'm not yet sure if the device detection really works. You better do things more slowly, i.e step-by-step. I suggest you repeat the following on either system, and make sure that you record the results of each step to be able to compare the exact (!!) differences (e.g. save all files onto a USB drive and do a thorough comparison):

• (1) Have your device initially disconnected, and boot with boot code 'base' (to reduce any potential side effects). Take a snapshot with: dmesg > dmesg_initial
• (2) Now test the "basic" device recognition, by connecting your device and take another snapshot: dmesg > dmesg_connected There should be a small number of additional entries that become "visible" via diff -U 0 dmesg_initial dmesg_connected
• (3) Now "install" the driver (via tce-load -i usb-serial-2.6.33.3-tinycore) and take one more snapshot: dmesg > dmesg_installed And again look at "what's new" via diff -U 0 dmesg_connected dmesg_installed

I'm expecting that you should now be able to identify in which step the differences occur.

[michaelkj77]

Further news...I put the computer booting off of a compact flash on an internet connection and downloaded the usb-serial.....tcz.  The version on the list though was 2.6.29.1, not 2.6.33.3.  Not sure why one computer sees the newer version on the app list and the other sees an older version, but I downloaded the older version and installed it.  Then added it to the onboot.lst file.  It works.  The drivers appear where they should, and the device is recognized and given /dev/ttyUSB0.  The GPS is blinking green happily.  Thanks to all for the assistance.  By the way, it looks like support for PL2303 and cypress_m8 (delorme) were loaded so both work.    

[maro]

Hmmm, that sounds "fishy": The extensions with 2.6.29.1 is for the kernel version used during the TC 2.x phase. If you download extensions in a kind of "offline" situation you'll have to be super-careful to target the correct repository (i.e. http://distro.ibiblio.org/pub/linux/distributions/tinycorelinux/3.x/tcz/ for TC 3.x). You better double-check all extension files on your "offline" system.

[michaelkj77]

I appreciate the advice and will do just as you suggested.  The current setup seems to work well, but I want to avoid any unforseen problems.