Differences LKL202-25 instead of 24?

[erics84]

I just received the LKL202-25-USB in the mail. After a lot of trouble trying to get it to work in linux, I'm getting some operation, but it is not perfect.

First I had to use mprog to increase wMaxPacketSize beyond zero so that I could write to the display at all. I'm hoping I did everything right by reading and parsing and simply writing back. This is where I could have gone wrong.

Second I have to use "modprobe ftdi_sio vendor=0x1b3d product=0x155" to get the device recognized since it is USB. Is there a way to have this happen automatically without patching the kernel? (Could I write my own product ID that would be recognized for my own intents and purposes?)

Now I can use LCD4Linux and it works great (provided I'm not using a cheap USB hub). However, this program is not as full featured as I would hope. I try to use LCDd and lcdproc, but instead of a solid block, an inverted P shows and garbage routinely pops up all over the screen. I'm using the MtxOrb driver at 19200bps to /dev/ttyUSB0. When I use uProject to set brightness on a windows machine, garbage floods the screen there too.

[Ray]

I just received the LKL202-25-USB in the mail. After a lot of trouble trying to get it to work in linux, I'm getting some operation, but it is not perfect.

First I had to use mprog to increase wMaxPacketSize beyond zero so that I could write to the display at all. I'm hoping I did everything right by reading and parsing and simply writing back. This is where I could have gone wrong.

Did you verify with lsusb -v that this step was really needed? We fixed the issue on our end. If it still was bad I would like to know when this unit was ordered and shipped to you though since this problem should not be there anymore.

Second I have to use "modprobe ftdi_sio vendor=0x1b3d product=0x155" to get the device recognized since it is USB. Is there a way to have this happen automatically without patching the kernel? (Could I write my own product ID that would be recognized for my own intents and purposes?)

We're hoping to get all our products supported again in a future kernel version but for now you have two options:

1) put the modprobe somewhere in your init scripts
2) Put the FTDI default PID/VID back into the eeprom so the FTDI_SIO driver will recognize it.

Now I can use LCD4Linux and it works great (provided I'm not using a cheap USB hub). However, this program is not as full featured as I would hope. I try to use LCDd and lcdproc, but instead of a solid block, an inverted P shows and garbage routinely pops up all over the screen. I'm using the MtxOrb driver at 19200bps to /dev/ttyUSB0. When I use uProject to set brightness on a windows machine, garbage floods the screen there too.

I have no idea on this one, I will ask the engineer in charge of this unit to get back on you on this.

[Raquel]

Hello Eric,

The 'P's that you see on the screen is the result of sending 0xFF to the display which has a European character set. The LK202-25-USB comes with European character set by default. We used to use Japanese font character set that showed a block when 0xFF is sent. Watch out for when LCDd send these 0xFF's, if you need to draw a block on the screen, try making a customer character for it, and call that custom character, instead of 0xFF.

As per contrast / brightness slider, uProject has got a little bug that it sends extra characters when you slide the bar. Try moving the bar using left, right arrow (ie. an incremental change) and this should eliminate the garbage characters.

Best Regards,

[erics84]

Did you verify with lsusb -v that this step was really needed? We fixed the issue on our end. If it still was bad I would like to know when this unit was ordered and shipped to you though since this problem should not be there anymore.

Yes, I verified this. I ordered this last Sunday (March 30, 2008), so you probably received the order on the 31st and it was in my hands on the 2nd of April.

2) Put the FTDI default PID/VID back into the eeprom so the FTDI_SIO driver will recognize it.

What is the default VID/PID?

The 'P's that you see on the screen is the result of sending 0xFF to the display which has a European character set. The LK202-25-USB comes with European character set by default. We used to use Japanese font character set that showed a block when 0xFF is sent. Watch out for when LCDd send these 0xFF's, if you need to draw a block on the screen, try making a customer character for it, and call that custom character, instead of 0xFF.

Is there a way to put the Japanese set back in? I don't think I'm well versed enough to alter the LCD software to do what I want. I'll have to look into lcdproc a little more to find out why the letter "K" is randomly appearing all over now that the inverted "P" character has been explained.

[Clark]

Hi Eric,

Looks like Ray has got the Linux based questions covered on this one, I'll see if I can help Raquel out on the fonts. The fonts are actually text sets that are saved into the screen itself. These are set by the manufacturer of the screen itself, and unfortunately cannot be changed through software means.

Matrix Orbital uses two different font style displays: European and Japanese. I've attached each so you can have a look at the characters on each, as I know it can be hard to explain some of the extended symbols.

Hopefully, this will help you understand which command is being sent to create the character on the screen. As you can see, the block and chromatically inverted 'P' are sent via command 0xFF hex or 255 decimal.

Thanks,
Troy

[Ray]

2) Put the FTDI default PID/VID back into the eeprom so the FTDI_SIO driver will recognize it.

What is the default VID/PID?

vid 0x0403, pid 0x6001 but there's a combobox above those fields in mprog where you can just select 'FTDI default' and save your self 8 keystrokes