need help in glcd - Page 2 - Electronic Circuits Projects Diagrams Free

darsin · 17th July 2008, 12:45 PM

this is my schematic, others i a bit lazy to draw it out.
i'm using ICD2 to program...
is it the problem is on my potentiometer part?
i'm using 10k...

Pommie · 17th July 2008, 12:59 PM

I can't find a data sheet for that display so I'm not sure but I would think that Vout should go to the top of the potentiometer. Have you changed the 16 #defines in GLCD.h to match your circuit?

If you setup your ICD2 as debugger and hit pause after it has run, which line does it stop on?

Mike.

Pommie · 17th July 2008, 01:05 PM

BTW, where is your crystal?

If you don't have one then that is the problem.

It can be changed to the internal oscillator if needed.

Mike.
edit, if this is your problem then you need to change the following bits in main.c

Code:

#include <p18f4550.h>
#include <GLCD.h>

#pragma config WDT = OFF, LVP = OFF, FOSC = INTOSCIO_EC

const rom unsigned char Logo[];

void main (void){
unsigned char i;
    OSCCON=0x70;               //added
    ADCON1=0x0f;               // all digital
    CMCON=7;                   // no comparators
    Init_GLCD();

darsin · 17th July 2008, 01:18 PM

yes! i changed it. the data sheet i had posted in the 1st post.
I connected 20MHz crystal on my circuit board already.
i just using the ICD2 programmer but not the debugger.

Pommie · 17th July 2008, 01:31 PM

Try changing it to the internal oscillator anyway. Your crystal may not be starting up correctly. You don't need to change your circuit, just the code.

Mike.

darsin · 17th July 2008, 01:58 PM

unfortunately....still nothing come out
my GLCD spoilt d?

darsin · 17th July 2008, 03:56 PM

pommie, you can't help me already?

blueroomelectronics · 17th July 2008, 04:08 PM

Connect your GLCD as the schematic in the Unicorn manual has it. (GND the CD3 & 4 lines). Add a couple of 0.1uF caps to the VDD & VSS pins on the 18F4550 if you haven't already.
You have your contrast pot connected incorrectly. Pin 20 is -VEE (out)
the pot should be around 20K and one end to +5, the other to pin 20 and the wiper to pin 3.

darsin · 17th July 2008, 04:30 PM

i'd made a development board already
just to connect my hardware to the port only
I do not have 20k pot so can i series 2 10k together?
do u mean that the wiper is the center pin of the pot?
so 1st pin is vdd,2nd pin is pin3 and 3rd pin is pin20?
am i correct?

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17th July 2008, 12:59 PM	(permalink)
Pommie	I can't find a data sheet for that display so I'm not sure but I would think that Vout should go to the top of the potentiometer. Have you changed the 16 #defines in GLCD.h to match your circuit? If you setup your ICD2 as debugger and hit pause after it has run, which line does it stop on? Mike.

17th July 2008, 01:05 PM	(permalink)
Pommie	BTW, where is your crystal? If you don't have one then that is the problem. It can be changed to the internal oscillator if needed. Mike. edit, if this is your problem then you need to change the following bits in main.c Code: #include <p18f4550.h> #include <GLCD.h> #pragma config WDT = OFF, LVP = OFF, FOSC = INTOSCIO_EC const rom unsigned char Logo[]; void main (void){ unsigned char i; OSCCON=0x70; //added ADCON1=0x0f; // all digital CMCON=7; // no comparators Init_GLCD(); Last edited by Pommie; 17th July 2008 at 01:12 PM. Reason: added code.

17th July 2008, 01:18 PM	(permalink)
darsin	yes! i changed it. the data sheet i had posted in the 1st post. I connected 20MHz crystal on my circuit board already. i just using the ICD2 programmer but not the debugger.

17th July 2008, 01:31 PM	(permalink)
Pommie	Try changing it to the internal oscillator anyway. Your crystal may not be starting up correctly. You don't need to change your circuit, just the code. Mike.

17th July 2008, 01:58 PM	(permalink)
darsin	unfortunately....still nothing come out my GLCD spoilt d?

17th July 2008, 03:56 PM	(permalink)
darsin	pommie, you can't help me already?

17th July 2008, 04:08 PM	(permalink)
blueroomelectronics	Connect your GLCD as the schematic in the Unicorn manual has it. (GND the CD3 & 4 lines). Add a couple of 0.1uF caps to the VDD & VSS pins on the 18F4550 if you haven't already. You have your contrast pot connected incorrectly. Pin 20 is -VEE (out) the pot should be around 20K and one end to +5, the other to pin 20 and the wiper to pin 3. __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

17th July 2008, 04:30 PM	(permalink)
darsin	i'd made a development board already just to connect my hardware to the port only I do not have 20k pot so can i series 2 10k together? do u mean that the wiper is the center pin of the pot? so 1st pin is vdd,2nd pin is pin3 and 3rd pin is pin20? am i correct?