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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| ks0108 128x64glcd interface problem |
 Posted: Thu Mar 15, 2012 1:43 pm |
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Dear all,
I am having a tough time interfacing pic16f877a with Glcd 128x64 running in KS0108. I am getting all the data being sent displayed. The problem is only half the display is always displayed. I can' make the full display to show any content. I am attaching the screenshot and the program.
I am using ccs compiler and the example programs and default drivers.
http://www.edaboard.com/attachments/70863d1331801572-photo-0012.jpg
http://www.edaboard.com/attachments/70864d1331801632-photo-0003.jpg
| Code: |
#include <HDM64GS12.c>
#include <graphics.c>
#include <math.h>
#byte trisa=0x85
#byte trisb=0x86
#byte trisc=0x87
#byte trisd=0x88
#byte trise=0x89
#byte porta=0x05
#byte portb=0x06
#byte portc=0x07
#byte portd=0x08
void displayVoltage(int adc) {
char voltage[9];
sprintf(voltage, "%f", (float)adc * .01960784); // Converts adc to text
voltage[4] = '\0'; // Limit shown digits to 3
glcd_rect(45, 18, 69, 25, YES, OFF); // Clear the old voltage
glcd_text57(45, 18, voltage, 1, ON); // Write the new voltage
}
void main() {
int1 warn = FALSE;
int8 adc = 0, adc_old = 0;
char voltText[] = "VoLtS\0", warning[] = "Warning";
float theta = 0;
setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
TRISA = 0x00;
TRISB = 0x00;
TRISC = 0x00;
TRISD = 0x00;
TRISE = 0x00;
porta=0x00;
while(1)
{
glcd_init(ON); // Must initialize the LCD
//glcd_rect(1, 1, 126, 126, YES, ON); // Outline the bar
glcd_text57(50, 100, voltText, 1, ON); // Display "Volts"
glcd_circle(30,47, 10, NO, ON); // Draw the clock circle
porta=~porta;
delay_ms(300);
// for(;;) {
adc = read_adc(); // Read a value from the ADC
displayVoltage(adc); // Display the reading
adc = (adc > 249) ? 249 : adc; // Keep the value 249 or less
if(adc != adc_old) {
glcd_rect(adc/2+1, 6, adc_old/2+1, 14, YES, OFF); // Clears the old bar
glcd_rect(1, 6, adc/2+1, 14, YES, ON); // Draws a new bar
adc_old = adc; // Set old value to new
if(adc > 200 && !warn) { // Check if over 4 volts
glcd_rect(45, 38, 124, 55, YES, ON); // Draw a filled black rectangle
glcd_text57(47, 40, warning, 2, OFF); // Write "Warning" on the LCD
warn = TRUE; }
else if(adc <=200 && warn) {
glcd_rect(45, 37, 125, 55, YES, OFF); // Draw a filled white rectangle
warn = FALSE; }
}
// The following 3 lines make the clock hand spin around
glcd_line(30, 47, 30+(int)(8*sin(theta)+.5), 47-(int)(8*cos(theta)+.5), OFF);
theta = (theta > 5.9) ? 0 : (theta += .3);
glcd_line(30, 47, 30+(int)(8*sin(theta)+.5), 47-(int)(8*cos(theta)+.5), ON);
#ifdef FAST_GLCD
glcd_update();
#else
delay_ms(100); // Reduces flicker by allowing pixels to be on
// much longer than off
#endif
}
}
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Fri Mar 16, 2012 7:55 am |
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Hi,
The KS0108 uses two chip select lines, CS1 and CS2. Each one controls half the display, so your problem description suggests an issue in this area. You really should not be manually setting TRIS, so errors here are a possibility. Also be sure that neither chip select is connected to a pin that is "open drain".
John |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 8:05 am |
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| ezflyr wrote: | Hi,
The KS0108 uses two chip select lines, CS1and CS2. Each one controls half the display, so your problem description suggests an issue in this area. You really should not be manually setting TRIS, so errors here are a possibility. Also be sure that neither chip select is connected to a pin that is "open drain".
John |
i will check on the CS pins, what is your suggestion on the MANUALLY selecting the TRIS i didn't get you on that sorry. |
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Fri Mar 16, 2012 8:12 am |
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Hi,
The default compiler mode is 'standardio' where the compiler sets the TRIS automatically.
John |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 8:37 am |
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| ezflyr wrote: | Hi,
The default compiler mode is 'standardio' where the compiler sets the TRIS automatically.
John |
I hope you would be knowing that am using picc compiler.
If so can you just explain in detail what you are saying as I am still in a confusion on standardio you were telling. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 16, 2012 1:05 pm |
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He means the CCS compiler will automatically set the correct TRIS for
you, if you use their built-in functions. You don't need to directly set the TRIS.
Post a list of all your connections between the PIC and the GLCD.
Also, check the connections to make sure they are correct. |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 3:23 pm |
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| PCM programmer wrote: | He means the CCS compiler will automatically set the correct TRIS for
you, if you use their built-in functions. You don't need to directly set the TRIS.
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Should I be using any default driver or library files for that ? I don't know this functionality in detail.
Can you please give the function names for doing so.
How will the compiler be knowing of our requirement of setting the pins in ports as IP or OP ?
| Quote: |
Post a list of all your connections between the PIC and the GLCD.
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The pin connections are as in the default glcd driver in picc compiler directory for the file GLCD.c
| Code: |
* 1: VSS is connected to GND ////
//// * 2: VDD is connected to +5V ////
//// * 3: V0 - LCD operating voltage is connected from a 20k Ohm POT////
//// * 4: D/I - Data or Instruction is connected to B2 ////
//// * 5: R/W - Read or Write is connected to B4 ////
//// * 6: Enable is connected to B5 ////
//// *7-14: Data Bus 0 to 7 is connected to port d ////
//// *15: Chip Select 1 is connected to B0 ////
//// *16: Chip Select 2 is connected to B1 ////
//// *17: Reset is connected to C0 ////
//// *18: Negative voltage is also connected to the 20k Ohm POT ////
//// *19: Positive voltage for LED backlight is connected to +5V ////
//// *20: Negavtive voltage for LED backlight is connected to GND ////
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| Quote: |
Also, check the connections to make sure they are correct. |
The connections are double checked. |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 3:28 pm |
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| ezflyr wrote: | Hi,
The KS0108 uses two chip select lines, CS1 and CS2. Each one controls half the display, so your problem description suggests an issue in this area. You really should not be manually setting TRIS, so errors here are a possibility. Also be sure that neither chip select is connected to a pin that is "open drain".
John |
hope PORTB0 & PORTB1 is not open drain. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 16, 2012 4:11 pm |
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Here is a way to let CCS handle the TRIS:
| Quote: |
#byte trisa=0x85
#byte trisb=0x86
#byte trisc=0x87
#byte trisd=0x88
#byte trise=0x89
#byte porta=0x05
#byte portb=0x06
#byte portc=0x07
#byte portd=0x08 |
Delete all the above lines.
Also if you have a line for #use fast_io, then delete it.
| Quote: |
TRISA = 0x00;
TRISB = 0x00;
TRISC = 0x00;
TRISD = 0x00;
TRISE = 0x00;
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Delete all the above.
Delete this, and add the following:
| Code: |
int8 porta_value;
porta_value = 0;
output_a(porta_value);
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Delete this and change it to:
| Code: |
porta_value = ~porta_value;
output_a(porta_value);
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 11:00 pm |
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| PCM programmer wrote: | Here is a way to let CCS handle the TRIS:
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so you say the compiler would automatically comes the know the tris configuration we need to have?
just to clear myself
say all my portc pins are inputs except for portc0 which i have given for glcd enable will my compiler set trisc accordingly? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 16, 2012 11:21 pm |
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Yes, it will. The compiler generates code to set the correct TRIS when
it sees these lines:
| Code: |
output_high(GLCD_E);
output_low(GLCD_E);
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Set the .LST file format for "Symbolic" in the Project / Build Options menu
and then compile the file. Look at those lines in the .LST file and you
will see that the compiler sets the TRIS to output whenever it executes
those lines. |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Fri Mar 16, 2012 11:32 pm |
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| PCM programmer wrote: | | Yes, it will. . |
thank you so much sir
sir can you just post the HDM64GS12.c, GLCD.h GLCD.c files for my use
am now getting not sure of the integrity of the files i have, also may i ask i have been using 4Mhz crystal for my board. but when i look in the example program i used from the picc directory EX_GLCD.C i just noticed this
| Code: |
#if defined(__PCM__)
#include <16F877.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#elif defined(__PCH__)
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#define FAST_GLCD // Try commenting this out to see the differences
#endif
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where i replaced all the above lines to suite my project
what am concerned from the example program now in this is this line
| Code: |
#use delay(clock=20000000)
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for this should i be modifying the delay values in the GLCD.c and HDM64GS12.c files to suite them for 4Mhz? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 16, 2012 11:59 pm |
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We are not allowed to post CCS files. If you have the compiler, then
you have the files. If you don't trust them, then re-install the compiler
or get a later version of the compiler.
If you are using a 4 MHz crystal, then change the #use delay() statement
to 4 MHz. The #use delay() statement must match the oscillator
frequency of the PIC.
Don't modify the delay values in any of the files. Just edit the #use delay
value to match your PIC oscillator frequency. The compiler will
automatically adjust the delays to be correct. |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Sat Mar 17, 2012 4:04 am |
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| ezflyr wrote: | Hi,
The KS0108 uses two chip select lines, CS1 and CS2. Each one controls half the display, so your problem description suggests an issue in this area. You really should not be manually setting TRIS, so errors here are a possibility. Also be sure that neither chip select is connected to a pin that is "open drain".
John |
i have checked for the pins integrity its seems fine.as you said i noticed the changes cs1 and cs2 could make in pic simulator. i tried the same in my code still nothing.
i tried even changing the portB to portC still no luck the half display remains the same only thing i could figure out is that(if as ezflyr says) the problem could be with none other than CS2 pin connected to portB.1 later changed to portc.2
i dont find trouble while running in simulator it works just fine but not in the hardware. i have double checked the hardware and the lcd too.
please help sir |
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sresam89
Joined: 15 Mar 2012
Posts: 20
Location: India
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| Posted: Sat Mar 17, 2012 6:14 am |
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dear pcm programmer and ezflyr
i tried an exchange between cs1 and cs2 pins then am getting the other half of the display on the left side, confirming that my datas are coming out properly. but why is that only my left side of the display is only working not the right?
i have attached the link to a snap taken after the exchange of the CS pins
is there any other method to check the full functionality of my display?
[img]
https://picasaweb.google.com/sresam89/Project?authkey=Gv1sRgCP3WsOikn7-kcw
[/img]
please help |
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