GLCD JHD12864E back led problem.....

[saur]

I tried to display gaph on my glcd and I succeeded......with the back led off....
But when I try the same with the back led on.....nothing is displayed or the display is too dim....
I feel its because the current sourcing is not sufficient......
So what can be the possible way to display graph with back led on.....
Pls give any suggestion you all have.....
Thanks in advance.....

 

[wp100]

I tried to display gaph on my glcd and I succeeded......with the back led off....
But when I try the same with the back led on.....nothing is displayed or the display is too dim....
I feel its because the current sourcing is not sufficient......
So what can be the possible way to display graph with back led on.....
Pls give any suggestion you all have.....
Thanks in advance.....

Hi,

According to the datasheet pins 19 and 20 are for the b/l at 5v.

Assume you are feeding that off the same 5v as the rest of the circuit ?

The problem will probably be that your +5v regulator / power source cannot provide enough current for the b/l and it is lowering the voltage to all the circuits.

To prove the point either drive the b/l from another totally separate power source / regulator or 3 x 1.5 v batteries to prove the point.

You could use something like a LM317 adjustable regulator, then you can easily dim the backlight to the required level.