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dieter
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| LCD on 18f6585 not working.... |
 Posted: Sat Oct 08, 2005 5:27 pm |
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Hi, i connected a 16x2 lcd which i tested with standard lcd.c driver on a pic. So far, so well. Now i connected it on other pins as the following:
RS:A4
RW.B2
EN:D2
Data0-3:B4-B7
the lcd is connected via a flat cable(20cm) and every line is pulled-up by a resitor of 50k. Contrast on pin 3 works correctly and is visible. But the display wont work...Even with marks driver...every line is connected on its right place as i tihnk. is there another fuse to set or does enable line not need any pullup? i already disabled all_analogs. but it still doesnt work on my 18f6585... what could be wrong? thanks... |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sat Oct 08, 2005 9:48 pm |
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When an LCD is used in 4-bit mode, it uses the upper 4 bits to talk
to the micro-controller. i.e., DB4-DB7 on the LCD.
You're using the lower 4 bits on the LCD. So you need to change that. |
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dietmar
Guest
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| Posted: Sun Oct 09, 2005 4:19 am |
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| Well this is not my problem. propably is was a fault to say i use data0-3, but i am already using D4-D7...This is not the problem i think... |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Oct 09, 2005 10:31 am |
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Try the LCD driver that I recently posted in the Code Library.
It's very easy to modify.
http://www.ccsinfo.com/forum/viewtopic.php?t=24661
To modify it for your board, just comment out the Pin definitions
at the top of the file and use these instead:
| Code: |
#define LCD_DB4 PIN_B4
#define LCD_DB5 PIN_B5
#define LCD_DB6 PIN_B6
#define LCD_DB7 PIN_B7
#define LCD_E PIN_D2
#define LCD_RS PIN_A4
#define LCD_RW PIN_B2
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To test it, write a simple program that outputs "Hello World" to
the LCD. Something like this:
| Code: | #include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#include <flex_lcd.c>
//=======================
void main()
{
setup_adc_ports(NO_ANALOGS);
lcd_init();
lcd_putc("Hello World");
while(1);
} |
Also, in a previous thread, you were planning to use a 74HCT14
schmitt trigger inverter chip. I assume that you removed that
chip for your tests. The lcd driver shown above will not work with
the inverter. So make sure you remove it. |
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