LCD and 16F877 | Piclist | EmbeddedRelated.com

Hi, I need help. I'm working in LCD display with PIC 16F877. My project is displaying messages on 16x2 LCD (Hitachi HD44780) with 4 bit interface. To make easy, I create a macro subroutine to send to the LCD. It's no problem when I only send little message. But... I have 21 message to display. Each message have 3 languages, and Each message contains 16 characters long. So. totaly I have 63 different messages. Now I'm using a Table Read mothode, but still have some problem. Not all the messages can be sent to the LCD. After message 27th can not be sent. I'm trying to change the code but still the same. May be someone have the good ideas ????? Thank you.

(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

Hi! When you are writing your source code you should take care of messages' positions in program memory, since you have a jump instruction in table read method. If you do not take care of it, program may jump some unwanted addresses. If you exceed one page to another you must load the proper page number to PCLATH before calling to jump instruction. (I mean Out_String function) If you are familiar with MPLAB use it to find program memory locations of your messages. If not see the list file which the assembler produces, in 1st column you may find the program memory addresses. As a second offer you wrote; + + To make easy, I create a macro subroutine to send to the LCD. + Are you calling that macro after each message if so the thing you are doing can be called waste of program memory. Use a subroutine instead of macro, since macro repeats all of its body whenever you call it. And that will occupy an important amount of program memory. Finally follow this link. http://technology.niagarac.on.ca/people/mcsele/TemperatureAlarm.htm This application (which belongs to M.Csele from Niagara College Ontario) will give you all important ideas of using an LCD and maintaining modular subroutines for it. Please also note org 100 at the starting of Strings and movlw 1 movwf PCLATH at the starting of Outstring function these 2 points is the issue which i mentioned as the first topic. See also Outstring function you will understand what i mean by a modular subroutine. Hope one of these will help and I did not bore you with the topics you already know. -- Best Regards G�khan �ZCAN -----Original Message----- From: "madajimmy" <> To: Date: Wed, 29 May 2002 06:11:15 -0000 Subject: [piclist] LCD and 16F877 > Hi, > > I need help. > I'm working in LCD display with PIC 16F877. > My project is displaying messages on 16x2 LCD (Hitachi HD44780) with > 4 bit interface. > To make easy, I create a macro subroutine to send to the LCD. > It's no problem when I only send little message. > But... > I have 21 message to display. > Each message have 3 languages, and > Each message contains 16 characters long. > So. totaly I have 63 different messages. > > Now I'm using a Table Read mothode, but still have some problem. > Not all the messages can be sent to the LCD. After message 27th can > not be sent. > I'm trying to change the code but still the same. > > May be someone have the good ideas ????? > > Thank you.

(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

Sign in

Search piclist

Subscribe to piclist

piclist by Keywords

Ads

Discussion Groups

Discussion Groups | Piclist | LCD and 16F877

LCD and 16F877 - madajimmy - May 29 1:11:00 2002

Re: LCD and 16F877 - GOKHAN OZCAN - May 30 11:03:00 2002