Discussion in "Project Doubts" started by    Okechukwu    Oct 9, 2014.
Thu Oct 09 2014, 10:01 am
#1
how do i reverse the output of p2 from the code, so that they will be inverted? i want to connect NPN transistor on them. Thanks.
Thu Oct 09 2014, 09:32 pm
#2
I think all you need to do, is to change ...
void display(char line,char ud)
{
	unsigned char j;	
	for(j=0;j<coloum;j++)
	{
		DSend(buffer[j] & ud);
	}
	P2=0xFF;
	latch();
	P2=~line;
}

to.....
void display(char line,char ud)
{
	unsigned char j;	
	for(j=0;j<coloum;j++)
	{
		DSend(buffer[j] & ud);
	}
	P2=0;
	latch();
	P2= line;
}

Fri Oct 10 2014, 12:11 am
#3
When posting a question its better to post a link to project if doubt is related to it. So it becomes easy for us to help you.
Tue Oct 14 2014, 08:13 am
#4
LED Scrolling display using 8051 project. Sir, which compiler should i use? Am using keil uVision4 but the my display is not showing very well. Furthermore, how can i increase the font size of the column from the code? Thanks once again. You guys are doing a wonderful job.
Wed Oct 15 2014, 11:05 pm
#5

Am using keil uVision4 but the my display is not showing very well.

Okechukwu


A very vague or open statement saying its not showing well. You should explain a bit more in detail like what is not working and what you see on the display. There are multiple factors that may cause display issue like different crystal value, improper delays etc. did you try with stock hex file provided? is it working fine?

Regarding font size... there will be changes in many areas, like font building array will also change accordingly. I cannot comment much on that as there will probably be lot of changes involved.
Tue Oct 21 2014, 11:59 pm
#6
@ Okechukwu
before starting this project you should be able to know about the logic that how this display works
for that read a dot matrix tutorial in tutorial section
i uses common cathode display if you use common anode hardware will be changed
for time being logic is as following
font size is (7*5) it can be 8*8 or more but as one port is 8 bit so it is better that size of rows should be 8 for more than 8 you need extra port in my case columns are 5 but it can be 8 or more depend on you
font can be generated using copy pencil or i post some software in project downloads by using that fonts can be generated these fonts is sent to rows of display all rows are common with all pieces ,columns are driven independently using ULN2803 NPN transistor array at a time one font is sent to rows and 1 column is one then next font and next column is on in this way a speedy refresh rate convert this into a display
to toggle a port value it can be
P2=~P2;

Get Social

Information

Powered by e107 Forum System

Downloads

Comments

RobertGug
Tue Jun 18 2024, 04:38 pm
Jasonabepe
Tue Jun 18 2024, 04:24 pm
Thomcyday
Tue Jun 18 2024, 08:38 am
WalterWib
Tue Jun 18 2024, 05:44 am
SialisshopWat
Mon Jun 17 2024, 09:22 pm
Thomasraima
Mon Jun 17 2024, 07:17 pm
EriksaLaf
Mon Jun 17 2024, 03:13 pm
Anthonyjinee
Mon Jun 17 2024, 06:23 am