5 Replies Latest reply on Jun 13, 2016 10:24 AM by michael.bey

    Help Programming I2C LCD Component to drive HD44780 LCD Display with PCF8574AT I2C Adaptor

    michael.bey

      The HD44780 2x16 LCD Display with an I2C adaptor is readily available and inexpensive and would like to use this display in my Project. Can someone help me with programming of the Custom Formatting option of the I2C_LCD component to Drive the HD44780 Display with a I2C PCF8574AT adaptor. I am using 0x7E to address the adaptor. When the display is initialized it will display 3 zeros on the fist line left to right which are always on. The PrintString, ClearDisplay and Position commands do not function. The screen is not cleared and no characters a sent to the display. The I2C NXP PCF2119x LCD Display that is provided by Cypress works fine. The best I can tell, the Cypress LCD and the HD44780 have a similar Command Sets except for the setting of the display to 2 lines and 16 characters, which is 0x38 instead of 0x24 for the Cypress LCD Display. The Command Pattern for sending data  appears to be 0x00 for the HD44780 and is 0x40 for the Cypress LCD display. I have tried both 0x00 and 0x40 and neither work. Would greatly appreciate some guidance. 

         

      Using the Character_LCD component is not an option for this Project.