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Michael Karas
03/23/12 10:33
Read: 536 times
Beaverton Or

#186834 - Using Read Cycle to LCD
Responding to: Erik Malund's previous message
Erik Malund said:
The wait LCD label is redundant,better off using a delay routine
where did you get that idea?
checking the LCD ready bit is, by far, the most reliable and fastest method.
that some posting amateurs have not figured that out is no reason for you to follow the herd.


There are a good number of cases where delays of some sort are necessary when dealing with LCD controllers. I have been tasked to work with a number of display modules where the interface cable from the MCU board over to the LCD was a narrow flex cable. The LCD manufacturers in these cases had elected to tie the RW line to the controller to a permanent "write" level on the module so as to save a conductor in the connection cable. Of course these applications also used the 4-bit mode to the display for exactly the same reason. As a result of this the software driver I supplied had to do its own delays because reading busy status from the controller was not possible.

Michael Karas

List of 13 messages in thread
4 Bit LCD      Sean O Mara      03/22/12 12:10      
   I am no sherlock Holmes, but ...      Erik Malund      03/22/12 13:31      
      LCD      Sean O Mara      03/22/12 13:56      
         Did you think about accesses using DATA1?      Per Westermark      03/22/12 15:41      
            lcd      Sean O Mara      03/22/12 17:18      
               So you found a solution ...      Andy Neil      03/22/12 18:02      
                  LCD 4 BIT      Sean O Mara      03/23/12 06:49      
                     where did you get that idea?      Erik Malund      03/23/12 06:57      
                        Using Read Cycle to LCD      Michael Karas      03/23/12 10:33      
                           of course, you can not use a signal that is not there      Erik Malund      03/23/12 10:45      
                        busy flad check      Sean O Mara      03/23/12 16:02      
                           Why not solve your problem BEFORE trying to save pins?        Richard Erlacher      03/24/12 08:16      
                              Premature optimisation      Andy Neil      03/24/12 09:48      

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