Atmel Stk500/501 And Skd204-634 V2.0


New member
Sorry i think its a silly question but i have a big problem.

i'm using an Atmel Mega103 on an STK501 dougterboard and
i try to connect a SKD204-634 V2.0 4*20 display to the serial connector of an ATMEL STK500 Board via 1:1 serial cable. I also connected the J1 GND and +5V Pin of the LCD to the correct PINS of the STK.

Switching Power on, the LCD shows the bootscreen (GND and +5V maybe correct) but when sending ASCII-data via the serial port nothing happens.
Doing the same with a serial connection to a PC the correct ASCII-data are displayed in an terminal programm ( maybe no software problem). :confused:

Has anybody a suggestion !

(sorry for my bad english)
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CF Tech

Try tracing the signal with the 'scope, making sure it shows up at the "DATA_IN" pin of the LCD.

Does the demo PCB put out 0-5v or true RS-232 levels? If it puts out 0-5v, try closing JPE, and then JPB if it still does not work.

Make sure the baud rates match.


New member
Thank you for your tips,

with a 1:1 serial cable the data_in pin(3) from the LCD was connected to the data_in pin(3) of the STK.
after soldering an new serial cable with only one wire form LCD pin 3 to STK data_out pin(2) anything works fine......:p