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)
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

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

USB LCD Displays - Graphic and Character LCDs with a Keypad