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LK204-25-422-R or LK204-25-R, which should i choose?

Posted: Sat May 08, 2010 8:16 am
by zyprexa
Hi

I'm looking for a red display, and have found LK204-25-422-R and LK204-25-R to my liking. But i'm wondering what is the difference, or can i use either one of them?

I would prefer to connect the display all internally in the computer chassis, so i'm also wondering what cables i should get to make it work with the least amount of modification?

I have a COM1 pin port on the motherboard of the computer it will be used on, but if i recall correctly there is no power-connection for floppy drive in it, only for harddrive IDE and SATA (it's a mini-itx chassis).

I'm also going to need a cable that can be connected externally while i make the program (on another computer). I'm planning to use Python with serial.

As you might have guessed i'm no electronics wizard, but i hope that's ok and that my questions can be answered :)

Posted: Mon May 10, 2010 9:08 am
by Clark
Hi Zyprexa,

The -422 in the part number of the first red display you've found signifies an RS422 compliant unit, for a serial (and TTL and I2C) solution you'll want the LK204-25-R. However, getting power to a serial unit may be tricky without a floppy power cable.

A USB option, the LK204-25-USB-R, is also available. This can connect externally to a regular mini USB cable and will create a virtual serial port for easy programming. You can also pick up a special internal USB cable from our site to house the display within your case build.

~Troy

Posted: Mon May 10, 2010 12:07 pm
by zyprexa
Thank you for the answer.
Clark wrote:The -422 in the part number of the first red display you've found signifies an RS422 compliant unit, for a serial (and TTL and I2C) solution you'll want the LK204-25-R. However, getting power to a serial unit may be tricky without a floppy power cable.
But is it possible? I'm not afraid to snip a wire here and there on the psu, as long as i dont have to solder directly on the motherboard.

Still, USB sounds like the best and easiest solution for me, but can/will it work in both Linux and Windows? The computer i will be making my program on is Windows (Vista), but the computer it will be running on is Linux (Ubuntu).

If it does i guess all i need is the display, an external USB cable and an internal USB cable?

Edit : Seems i overlooked the sticky about Linux and also found this. I would sleep better though if someone could confirm that this also applies to the LK204-25-USB-R display. 8)

Posted: Mon May 10, 2010 2:19 pm
by Clark
No worries Zyprexa,

Serial is indeed possible, but you will have to get 5v power from your supply to the display; without a floppy header this will probably involve soldering and/or crimping. I would agree that the USB is a better way to go.

USB programming is definitely not a problem in Windows with the virtual serial port and should not be an issue for Linux either. You can check out our app note online to see how to manually install drivers on Linux, if need be, and get started with a little hello world programming.

As for your list of parts for this project, the USB display, Internal, and External cables should do.

~Troy

Posted: Mon May 10, 2010 3:27 pm
by zyprexa
Thank you for all the help :)

I will go for the USB solution. Will put the order in first thing tomorrow.