8x8 dot matrix brightness problem?

Other Hardware Displays
1

Hi everyone

? tried to drive a dot matrix with my
arduino. i do the connections and load the code on the following page
http://www.arduino.cc/playground/Main/DirectDriveLEDMatrix
but the brightness of the matrix is not good enough to be seen on a day light
how can ? increase the brightness of the each individual LED
i try some delay for each LED but it does not response.

do u have any suggestion. thanks in advance

i also finish my last project. u can see the video and get the circuit schematic with source code http://barisdanacioglu.jimdo.com/elektronik/arduino-dersler-projeler/ultrasonik-sensörle-mesafe-ölçümü/

if i finish this i will write an other article about that

2

What resistor values did you use to limit current and where did you get the LEDs? Need a link.

3

Thanks for your attention :))
i solve the problem after ask to u
i only remove the current limiting resistors
and it works properly

you can watch demo video on my blog page

http://barisdanacioglu.jimdo.com/

4

Bad idea! Your arduino will soon burn up in pieces. If you want to avoid that, you need to put the resistors back and provide me the link to where you got your LEDs, just like I asked.

5

there is no problem on the LEDs because they works properly
when ? apply 5V and a 470 ohm resistors in series.
i think my problem is the same with this one

because at any time only one LED lights on, because i cant
set one port of the atmega328 with only one line code

the reasone is that atmega328 has three 8 bits port and
one port has RX/TX pins
one port has a RESET pin
one port has cyristal pins

so the question is how can we set 8 bits of arduino GPIO pins at one instruction
like PORTB=0XFF;
this instruction exist in arduIDE but cant set 8 bits..... hmmm.. is it possible i did not try :smiley:
if tx/rx pins can be used for GPIO it is possible but if cannot, we cant do this :smiley:

6

there is no problem on the LEDs because they works properly

No you are killing your arduino. Please read this:-
http://www.thebox.myzen.co.uk/Tutorial/LEDs.html

so the question is how can we set 8 bits of arduino GPIO pins at one instruction
like PORTB=0XFF;

You can't and there is no need to.

See:-
http://www.thebox.myzen.co.uk/Workshop/LED_Matrix.html