LCD Problem

[Trefor]

Hi All,
I have put together a program that works except for the LCD drive. You may recognise it from www.vermontficks.org. The problem that I am having is that the second line on the LCD refuses to work!!! The display is a powertip 2x16 alphanumeric TN and their data sheets says that a missing second line is due to either incorrect initialisation or wrongly set as a single line dispaly. However the program looks good as far as I can tell!! The code is below and any help will be much apreciated!!
Thanks
trefor

#include <16c74.h>
#include <math.h>
#define echo pin_c2
#define init pin_b6
#define binh pin_b7
#define lcd_d0 pin_b0
#define lcd_d1 pin_b1
#define lcd_d2 pin_b2
#define lcd_d3 pin_b3
#define lcd_en pin_b4
#define lcd_rs pin_b5
#define first_line 0x00
#define second_line 0x40
#define clear_disp 0x01


#separate void lcd_init (void);
#separate void lcd_setposition (unsigned int cX);
#separate void lcd_putchar (unsigned int cX);
#separate void lcd_putcmd (unsigned int cX);
#separate void lcd_pulseenable (void);
#separate void lcd_setdata (unsigned int cX);

#use delay (clock=20000000)
long value;
float time,time1,distance,angle,anglerad,calc1,hyp1,hyp2,tipdist;
const long k1=2,k2=66;
const float counttime=0.0000016,sos=13628,const1=2.95,const2=0.01745,const3=12,offset=1;

#separate lcd_init (void)
{
lcd_setdata (0x00);
delay_ms(200);
output_low (lcd_rs);
lcd_setdata (0x03);
lcd_pulseenable();
lcd_pulseenable();
lcd_pulseenable();
lcd_setdata (0x02);
lcd_pulseenable();
lcd_putcmd (0x2C);
lcd_putcmd (0x0C);
lcd_putcmd (0x01);
lcd_putcmd (0x06);
}

#separate void lcd_setdata (unsigned int cX)
{
output_bit (lcd_d0,cX&0x01);
output_bit (lcd_d1,cX&0x02);
output_bit (lcd_d2,cX&0x04);
output_bit (lcd_d3,cX&0x08);
}

#separate void lcd_pulseenable (void)
{
output_high (lcd_en);
delay_us(10);
output_low (lcd_en);
delay_ms(5);
}

#separate void lcd_putcmd (unsigned int cX)
{
lcd_setdata ( swap ( cX ) );
lcd_pulseenable();
lcd_setdata ( swap ( cX ) );
lcd_pulseenable();
}

#separate void lcd_setposition (unsigned int cX)
{
lcd_setdata (swap(cX|0x08));
lcd_pulseenable();
lcd_setdata (swap(cX));
lcd_pulseenable();
}

#separate void lcd_putchar (unsigned int cX)
{
output_high (lcd_rs);
lcd_setdata (swap(cX));
lcd_pulseenable();
lcd_setdata (swap(cX));
lcd_pulseenable();
output_low (lcd_rs);
}

main (void)
{
while (true)
{
set_tris_a (0xff);
set_tris_b (0x00);
setup_ccp1(ccp_capture_re);
setup_adc_ports(ra0_ra1_ra3_analog);
setup_adc(adc_clock_internal);
set_adc_channel(0);
enable_interrupts(int_ccp1);
enable_interrupts(global);
output_low (init);
output_low(binh);
delay_ms(200);
setup_timer_1(t1_internal);
output_high(init);
delay_us(900);
output_high(binh);
delay_ms(100);
output_low(init);
delay_ms(100);
time=ccp_1*counttime;
time1=time/k1;
distance=(time1*sos)+offset;
value=read_adc();
angle=(value-k2)/const1;
anglerad=angle*const2;
calc1=cos(anglerad);
hyp1=distance/calc1;
hyp2=hyp1-const3;
tipdist=hyp2*calc1;
lcd_init();
lcd_putcmd (clear_disp);
lcd_setposition(first_line);
printf (lcd_putchar,"tipdist=\%2.1f",tipdist);
lcd_setposition(second_line);
printf (lcd_putchar,"angle=\%2.1f",angle);
(true);
}
}
___________________________
This message was ported from CCS's old forum
Original Post ID: 13318

[PCM programmer]

:=Hi All,
:= I have put together a program that works except for the LCD drive. You may recognise it from www.vermontficks.org. The problem that I am having is that the second line on the LCD refuses to work!!! The display is a powertip 2x16 alphanumeric
------------------------------------------------------

They appear to have at least 14 different models of a 16x2 LCD.
Which one are you using ?
<a href="http://www.powertipusa.com/lcdc.htm" TARGET="_blank">http://www.powertipusa.com/lcdc.htm</a>
___________________________
This message was ported from CCS's old forum
Original Post ID: 13321

[Trefor]

Thanks for the quick reply!
The model number of the display is PC 1602-D
Hope this helps
trefor

:=:=Hi All,
:=:= I have put together a program that works except for the LCD drive. You may recognise it from www.vermontficks.org. The problem that I am having is that the second line on the LCD refuses to work!!! The display is a powertip 2x16 alphanumeric
:=------------------------------------------------------
:=
:=They appear to have at least 14 different models of a 16x2 LCD.
:=Which one are you using ?
:= <a href="http://www.powertipusa.com/lcdc.htm" TARGET="_blank"> <a href="http://www.powertipusa.com/lcdc.htm" TARGET="_blank">http://www.powertipusa.com/lcdc.htm</a></a>
___________________________
This message was ported from CCS's old forum
Original Post ID: 13322

[Rollo]

Hi!

I'm not at all sure if this is relevant to your case or not, but here goes...

I got an 1 x 16 LCD last week. Got it home and tried it out. It only showed data on the first 8 characters, and nothing to the right of that. I thought maybe the unit was defective. Researched it and wrote eMails and found out that my unit was considering the right half to be the "second line".

Long story short, I was able to get it to work, but only if I added a location type of command before my "second line". In my case, I'm using the lcd.c code from CCS.

lcd_gotoxy(1,1);
printf(lcd_putc, "Line#1\n");

lcd_gotoxy(1,0);
printf(lcd_putc, "Line#2\n");

There is a second way in which I was able to get it to work using one command line, but I found I had to be careful of the number of characters I sent. It goes like this...

lcd_gotoxy(1,1);
printf(lcd_putc, "Line#1 \nLine#2 ");

In my case, each side of that \n above has eight characters, which add up to 16, for my 1 x 16 LCD.

I don't see how my code bears any resemblance to yours. Looks to me like you're maybe not using lcd.c as I am. But just in case that positionning or the \n issue is helpful, I thought I should post a reply.

I hope this might be useful, somehow. If I'm misunderstanding the problem, then my apologies, as I'm only 2 weeks into PICs and CCS.

G'luck!
Rol






:=Hi All,
:= I have put together a program that works except for the LCD drive. You may recognise it from www.vermontficks.org. The problem that I am having is that the second line on the LCD refuses to work!!! The display is a powertip 2x16 alphanumeric TN and their data sheets says that a missing second line is due to either incorrect initialisation or wrongly set as a single line dispaly. However the program looks good as far as I can tell!! The code is below and any help will be much apreciated!!
:=Thanks
:= trefor
:=
:=#include <16c74.h>
:=#include <math.h>
:=#define echo pin_c2
:=#define init pin_b6
:=#define binh pin_b7
:=#define lcd_d0 pin_b0
:=#define lcd_d1 pin_b1
:=#define lcd_d2 pin_b2
:=#define lcd_d3 pin_b3
:=#define lcd_en pin_b4
:=#define lcd_rs pin_b5
:=#define first_line 0x00
:=#define second_line 0x40
:=#define clear_disp 0x01
:=
:=
:=#separate void lcd_init (void);
:=#separate void lcd_setposition (unsigned int cX);
:=#separate void lcd_putchar (unsigned int cX);
:=#separate void lcd_putcmd (unsigned int cX);
:=#separate void lcd_pulseenable (void);
:=#separate void lcd_setdata (unsigned int cX);
:=
:=#use delay (clock=20000000)
:=long value;
:=float time,time1,distance,angle,anglerad,calc1,hyp1,hyp2,tipdist;
:=const long k1=2,k2=66;
:=const float counttime=0.0000016,sos=13628,const1=2.95,const2=0.01745,const3=12,offset=1;
:=
:=#separate lcd_init (void)
:= {
:= lcd_setdata (0x00);
:= delay_ms(200);
:= output_low (lcd_rs);
:= lcd_setdata (0x03);
:= lcd_pulseenable();
:= lcd_pulseenable();
:= lcd_pulseenable();
:= lcd_setdata (0x02);
:= lcd_pulseenable();
:= lcd_putcmd (0x2C);
:= lcd_putcmd (0x0C);
:= lcd_putcmd (0x01);
:= lcd_putcmd (0x06);
:= }
:=
:=#separate void lcd_setdata (unsigned int cX)
:= {
:= output_bit (lcd_d0,cX&0x01);
:= output_bit (lcd_d1,cX&0x02);
:= output_bit (lcd_d2,cX&0x04);
:= output_bit (lcd_d3,cX&0x08);
:= }
:=
:=#separate void lcd_pulseenable (void)
:= {
:= output_high (lcd_en);
:= delay_us(10);
:= output_low (lcd_en);
:= delay_ms(5);
:= }
:=
:=#separate void lcd_putcmd (unsigned int cX)
:= {
:= lcd_setdata ( swap ( cX ) );
:= lcd_pulseenable();
:= lcd_setdata ( swap ( cX ) );
:= lcd_pulseenable();
:= }
:=
:=#separate void lcd_setposition (unsigned int cX)
:= {
:= lcd_setdata (swap(cX|0x08));
:= lcd_pulseenable();
:= lcd_setdata (swap(cX));
:= lcd_pulseenable();
:= }
:=
:=#separate void lcd_putchar (unsigned int cX)
:= {
:= output_high (lcd_rs);
:= lcd_setdata (swap(cX));
:= lcd_pulseenable();
:= lcd_setdata (swap(cX));
:= lcd_pulseenable();
:= output_low (lcd_rs);
:= }
:=
:=main (void)
:= {
:= while (true)
:= {
:= set_tris_a (0xff);
:= set_tris_b (0x00);
:= setup_ccp1(ccp_capture_re);
:= setup_adc_ports(ra0_ra1_ra3_analog);
:= setup_adc(adc_clock_internal);
:= set_adc_channel(0);
:= enable_interrupts(int_ccp1);
:= enable_interrupts(global);
:= output_low (init);
:= output_low(binh);
:= delay_ms(200);
:= setup_timer_1(t1_internal);
:= output_high(init);
:= delay_us(900);
:= output_high(binh);
:= delay_ms(100);
:= output_low(init);
:= delay_ms(100);
:= time=ccp_1*counttime;
:= time1=time/k1;
:= distance=(time1*sos)+offset;
:= value=read_adc();
:= angle=(value-k2)/const1;
:= anglerad=angle*const2;
:= calc1=cos(anglerad);
:= hyp1=distance/calc1;
:= hyp2=hyp1-const3;
:= tipdist=hyp2*calc1;
:= lcd_init();
:= lcd_putcmd (clear_disp);
:= lcd_setposition(first_line);
:= printf (lcd_putchar,"tipdist=\%2.1f",tipdist);
:= lcd_setposition(second_line);
:= printf (lcd_putchar,"angle=\%2.1f",angle);
:= (true);
:= }
:= }
___________________________
This message was ported from CCS's old forum
Original Post ID: 13323

[PCM programmer]

:=Thanks for the quick reply!
:= The model number of the display is PC 1602-D
--------------------------------------------------------

Given the model number, I was able to get the data sheet.
I had to get it by doing a web search because this company,
PowerTip, regards their LCD data sheets as "secret".
That does not give me a high opinion of the company.

But anyway, here's the solution:

The problem is in your lcd_setposition() routine. You have
changed a line of Mr. Fick's code, and that's why it doesn't
work. You have this:

lcd_setdata (swap(cX|0x08));

and it needs to be this:

lcd_setdata( swap ( cX ) | 0x08);

This line outputs the high nybble of data. The data sheet
shows that the high nybble must have the top bit set = 1.
So first you should do the swap on cX, to get the high nybble
into bit positions 0-3. Then, you OR it with 0x08, to set the
D3 bit. Then you output it.

Your code could have worked, if you did this:

lcd_setdata (swap(cX | 0x80));

This sets the top bit of the high nybble, and then swaps the
high nybble into bit positions 0-3, and outputs it.
___________________________
This message was ported from CCS's old forum
Original Post ID: 13326

[Trefor]

Thank you very much for this information!! I will modify the code and try it when Im back in college next week. Appologies for not replying untill now, I have been away working at the Aintree races.
I should learn from this, 'dont alter code that I do not understand!!'.
trefor




:=:=Thanks for the quick reply!
:=:= The model number of the display is PC 1602-D
:=--------------------------------------------------------
:=
:=Given the model number, I was able to get the data sheet.
:=I had to get it by doing a web search because this company,
:=PowerTip, regards their LCD data sheets as "secret".
:=That does not give me a high opinion of the company.
:=
:=But anyway, here's the solution:
:=
:=The problem is in your lcd_setposition() routine. You have
:=changed a line of Mr. Fick's code, and that's why it doesn't
:=work. You have this:
:=
:=lcd_setdata (swap(cX|0x08));
:=
:=and it needs to be this:
:=
:=lcd_setdata( swap ( cX ) | 0x08);
:=
:=This line outputs the high nybble of data. The data sheet
:=shows that the high nybble must have the top bit set = 1.
:=So first you should do the swap on cX, to get the high nybble
:=into bit positions 0-3. Then, you OR it with 0x08, to set the
:=D3 bit. Then you output it.
:=
:=Your code could have worked, if you did this:
:=
:=lcd_setdata (swap(cX | 0x80));
:=
:=This sets the top bit of the high nybble, and then swaps the
:=high nybble into bit positions 0-3, and outputs it.
___________________________
This message was ported from CCS's old forum
Original Post ID: 13445