Microcontroller and LCD interfacing problem

[ysrinivas1117]

Hi every one…
i am new to this forum,i am doing a mini project on microcontroller based security system in that i am getting LCD and Controller problem.i wrote the code for LCD using mazidi textbook as reference but i am not getting any character display or even cursor aslo. i am using the same port connections and the same code as it is in the mazidi text book but i dont know where the exact problem is can any one plzz help me to solve this problem.  

[AJISH ALFRED]

Hi,

Are you doing it on any development board? If not please post your connection diagram. An image of the LCD while the code is running would be really helpful for us to identify the problem.

 

[ysrinivas1117]

wysiwyg_imageupload:6908:

[ysrinivas1117]

 hi,
      Actually i am doing the project on general purpose PCB.
when the code is running the LCD back light is ON that’s it i am not getting even the cursor also.
          i posted the related circuit diagram if the problem can be solved by the circuit diagram it’s fine other wise i will post the project while running with in two days.
thanks for your reply

[AJISH ALFRED]

I can hardly identify the pins from the circuit diagram. You could have post a better image.

Anyway, what I found from the circuit that you’ve connected LED+ to VCC and LED- to GROUND. If you do so the LCD’s backlight will be at its maximum and even if some characters being displayed, we can’t see them. It can also damage the backlight permanently.

Better you connect the LED+ pin to the variable of a 10K pot and any other pin of the pot to VCC, so that you can adjust the brightness of the LCD by varying the pot. 

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