TextLCD_20X4

Page last updated 15 May 2010, by Yoshi Mimura. 0 replies LCD, RW

This is my first project on the mbed.

This is a modified version of TextLCD on the Cookbook for 20X4 LCD specific. This does not control RW line, so we can reduce the number of pin usage on the mbed.

Published Program

• TextLCD_20X4_Test

Reference

• http://mbed.org/projects/cookbook/wiki/TextLCD
• http://mbed.org/forum/mbed/topic/195/?page=2#comment-2260
• http://www.lcd-modules.com.tw/data/chsracter/SC2004C.pdf

Modification

• The locate() routine of TextLCD on the Cookbook does not work correctly on the 20X4 LCD, so I modified it to set the proper DD_RAM address on the LCD.
• The original TextLCD program assigns the RW control line, but it defined as "_rw = 0" and never been changed. Therefore, I remove the RW control line on the mbed, and the RW line on the LCD is connected to GND.

      01234567890123456789
     +--------------------+
   0 |80    TextLCD     93| (0,0) .. (19,0)
   1 |C0                D3| (0,1) .. (19,1)
   2 |94      20X4      A7| (0,2) .. (19,2)
   3 |D4                E7| (0,3) .. (19,3)
     +--------------------+

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