Lcd problem

[shah_siddiquee]

HI. I purchased a 16/2 lcd display for my project _ here is the datasheet (www.farnell.com/datasheets/40247.pdf ) i connected Lcd to my picaxe directly. I did not know the pinout of this lcd. So i used
(http://elinux.org/RPi_Tutorial_EGHS:Alpha-Numeric_Display) this website for pin config. Now the Lcd doesnot working. Even it does not blink for once. Although if i connected wrongly but when i put 0v and +v correctly it should make some different atleast. Can you guys help me please.

http://www.farnell.com/datasheets/40247.pdf
http://elinux.org/RPi_Tutorial_EGHS:Alpha-Numeric_Display

 

[russbow]

You quoted the datasheet and that gives the display pin out, so maybe read it again.

Read carefully Manual 3 page 31 onwards. That explains how to interface the LCD to the picaxe. All the answers are there.

Also Nick12ab has done some tutorials on 8 bit interfacing. Do a forum search and read those.

 

[srnet]

I did not know the pinout of this lcd.

The data sheet, whilst not of the best quality. does give the pinout.

Did you try it and it did not work ?

 

[MPep]

When I bought and assembled the AXE133 kit, I initially thought it didn't work. Then I adjusted the contrast and all was well.

Please supply us a diagram of your setup, photos, etc.
The datasheet does have all the info in it. It is confusingly written though.

 

[nick12ab]

What do you mean...

i connected wrongly

LCD driver ICs are a lot more sensitive to reverse power and over voltage than PICAXEs and a single mistake related to any of these is usually enough to kill the LCD module.

However make sure your new circuit is correct before you decide that. Ensure that the contrast connection is correct.

Link to tutorial

 

[shah_siddiquee]

followed datasheet

I connected all pin as the datasheet says. But still did not work.

 

[shah_siddiquee]

i think you are right.

Some how the module was killed. Because it doesnot responding at all. Anyway, is the contrast veriable resistor very important? Because i tried with fixed resistor, i haven't any VR. Can u tell me which connections are very important to check the module is ok?

 

[marks]

also have a read of post#36
http://www.picaxeforum.co.uk/showthread.php?19474-Learning-to-Drive-an-LCD-DISPLAY/page4
shows some common diagrams
and code to initialised a lcd in 4bit or 8bit
if contrast is set to high nothing will be seen

 

[mrburnette]

Some how the module was killed. Because it doesnot responding at all. Anyway, is the contrast veriable resistor very important? Because i tried with fixed resistor, i haven't any VR. Can u tell me which connections are very important to check the module is ok?

YES... Generally a 10K VR is recommended... You "could" perhaps use a fixed resistor ONLY AFTER using a VR to determine the proper resistance (such things being of the not recommended best practice.)

 

[inglewoodpete]

Use a potentiometer

Some how the module was killed. Because it doesnot responding at all. Anyway, is the contrast veriable resistor very important? Because i tried with fixed resistor, i haven't any VR. Can u tell me which connections are very important to check the module is ok?

When you can't seem to make the LCD module go, the power and variable resistor connections are the most important. The contrast potentiometer become the most important thing for testing. Get one: why does the manufacturer specify it?

If the LCD is working, adjusting the pot will cause one of the rows of character positions to change between nothing and contrasting 'blocks'. Only then will you know if your module can be made to work.

When using LCD modules you need to be patient, methodical and persistant.