| ??? 01/09/07 14:55 Read: times |
#130505 - Wrong plenty of research Responding to: ???'s previous message |
Russell Bull said:
Originally the LCD was a bus device. As time has moved on the old hitachi controller is woefully slow for such a task, so we have to 'bit bash' the interface - that is we toggle the LCD signals with code rather than relying on the internal hardware to do it for us. So the LCD control signals just connect to port pins. See the tutorials section on how to bit bash the LCD interface. If the software is well written, it is just a matter of changing a few routines to cope with the difference. The signals you need to take care of are: E R/!W RS D0..7 (there is also a 4bit mode so you only need 4 data bits) Depending on what the code expects, you can also not use the R/!W bit and tie it low (write only) as most of the time you only send data to the LCD. The only data usually read from the LCD is the ready status , but you can just use a time delay instead. Hi Russell: I did research it. I even set up my LCD to work with data bus switches and pull up resistors to try learn better how display works without a microcontroller controlling the rs,rw, e strobe and data bus D0-D7. Wright now I am not ready learn 4 bit bus if I can learn 8 bit I will be content. Yes it does work, but it will not help me understand how find the code differances in 80c31 w/r rd. I looked at this code 5 and 6 times trying understand what the engineer did. The fact that I can not share code makes it even harder to explain. Since I am still learning and not an expert like you Russell it not easy. This engineer uses women's names like Mary,Amy,Sherry etc. as his labels. So I kind of confused as what he is doing with code even with comments. I should not receive a negative coment because I don't understand the LCD differnces between the 80c31 and 89c4051 is no reason to give me negative comment. How about taking the negative comment away since I did do great deal of reasearch. Any way it's 25 pages of code even engineer talked to at C.C.I. did not understand completely. Because engineer that wrote this code also made test programs in the code. Five different programs with the test code makes it hard to follow if you are not and expert programmer. Best regards, Ralph Sac |
