[Please HELP!!!] Semi-garbage on Screen w/ 634 via USB PCMCIA on a 486DX4 133


New member
Hello, All

I've currently working on a embedded project at work that uses a 634 with Sokris net4021 board these boards are running Linux 2.4 kernel with a PCMCIA USB card. The LCD device is detect by the Linux standard kernel driver and is powered on. However, when the program is executed tons of sendByte errors and some garbage on the screen however so of the text is displayed correctly. The program is a custom program based of the example test634 program form your web site. This program and the LCD work perfectly on a normal PC with a built in USB slots. Any clues? Have you heard of this before?
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CF Tech

Is there any chance that the embedded board has a serial port available? Avoiding USB would certainly be the easiest and least costly way to "fix" it.

Beyond that, I am not sure how to proceed. Is there a way to check the driver version for the PCMCIA USB card and the FTDI drivers? (Sorry, but I am not much of a Linux expert :( )

There is not supposed to be anything special about sending bytes to the CFA-634. Can you try a terminal program?


New member
The FTDI driver is version
ftdi_sio.c: v1.3.4:USB FTDI Serial Converters Driver

PCMCIA: Linux Kernel Card Services 3.1.22

This is the version the dones not seems to work! However i'm not sure if this is the cause or not.

There is a serial port however i really need it so that i can debug and see the board on POST.

CF Web

Have you had any success using other USB devices through the PCMCIA card?

If possible, try using a USB flash drive, mouse, or some other device and let us know if it works properly.


New member
Yes... I've been able to use a usb keyboard and a USB card scanner( mag strip) all those work just fine. The LCD power on just fine its just that on initilization the lcd starts scrolling then some garbage gets printed and then some of the real data is there. In my program i echo out the data fromthe keyboard to the lcd all of which works just fine.

I'm feeling stuck...