LK202-25 and simple PC interface

lewistower2 · Post by **lewistower2** » Wed Mar 31, 2004 6:35 pm

Sorry in advance as a Newbie

I recently puchased an LK202-25-GW with aspirations of using it with a Javelin stamp. I am having problems just getting it to communicate with my PC comm , whether through Hypertem or the (well done) LCD Tester. Baud is 19200, 9-pin is not NullModem (though I did try it) etc. The LCD Tester is not able to determine type or serial number, no commands work. I get characters, but mostly a lot of ||| pipes. If anyone can lend a hand, I'd really appreciate it.

Miles · Post by **Miles** » Thu Apr 01, 2004 9:15 am

Hello...

Where did you purchase the display from??

lewistower2 · Post by **lewistower2** » Thu Apr 01, 2004 11:24 am

From Parallax.

I have seen issues about the power supply ( is it TTL or something), if that's where we are going. I have the LCD wired directly off the parallax board VDD and VSS (5 volts) when I run it from the javelin or from the PC. In both cases I get the same exact results, character for character, whether it's PC or javelin. Also I should note that when the LCD starts up there is a || in the upper left of the normal startup screen.

Sorry if this is turning hardware.

Miles · Post by **Miles** » Thu Apr 01, 2004 11:58 am

Since you ordered the unit from Parallax, it's default communication protocol is TTL. This is why the unit will not work when connected to your PC com ports. If you want to test the unit using your PC, you must modify to RS232 communication. Please refer to section 2.1.3 in your manual.