LCD trouble

Hi, I’ve got a problem with my lcd that i can’t seem to find the answer to.

Arduino deumilanove running 0017
LCD screen http://www.pieterfloris.nl/shop/product.php?id_product=43
woohooo wiring scheme found

sketch found
this one

adapted the library to the special needs of the lcd

( a small tweak to accomodate the four rows of 16 char

Change

int row_offsets = { 0x00, 0x40, 0x14, 0x50 };

into

int row_offsets = { 0x00, 0x40, 0x10, 0x50 };

I powered the backlight pin 15/16 with a 330 resistor and the gnd.

and now

expensive smells and sparks at pin two pin VDD :frowning:

sooo what did i do wrong ?

any help would be greatly appreciated

regs

Wouter

That looks OK, make sure that is actually what you had.

In particular look at the connections to the pot and make sure you got the wiper connection identified correctly.

Hi Mike
thanks for the speedy reply
I checked everyting twice

The vendor replied almost instantly (thanks Pieter from Floris.cc) and he suggested i use http://www.adafruit.com/index.php?main_page=product_info&cPath=37&products_id=181

this scheme :slight_smile:

let’s see if there’s still some life in it left, i’ll keep you posted :smiley:

meh still smoke on pin VDD :frowning:

Yes that was the bit I was unsure about, normally the contrast pot is not connected to the +5V but just left floating.

On some this has to be connected to a negative voltage. Maybe you have a negative voltage generator on that LCD and you are shorting it out.

expensive smells and sparks at pin two pin VDD Sad

sooo what did i do wrong ?

From this description my guess is that you have the power leads reversed.

Don

Nope checked It’s wired exactly as on the pictures i guess i must have shorted it out while attemping to set it up before.

I spoke to the supplier and he graciously gave me a discount so although the learning curve was somewhat steep it wasn’t that expensive.

I don’t see a data sheet for that LCD, but it does say that it has a back light. On my LCD with backlight (from adafruit, here) you need to connect pin 15 to +5V and 16 to GND for the back light.

I’ve got the same lcd from samenkopen.net (dutch language)

The data sheet is here:

http://www.thempolis.nl/arne/files/YC-1604A.pdf

…which confirms pins 15 & 16 are needed for backlight power.

…which confirms pins 15 & 16 are needed for backlight power.

This is correct but irrelevant with respect to the original problem. His problem was with smoke on the power the power pin for the LCD controller, specifically pin 2. The 14-pin LCD interface is independent of the 2-pin LED interface.

Don

Yes, I was just pointing out the error in the schematic.

Have you tryed connecting just 5v and ground to the appropriate pins to see if the LCD powers on?

Have you tryed connecting just 5v and ground to the appropriate pins to see if the LCD powers on?

That won’t do you much good if you don’t also deal with the LCD drive (contrast) on pin 3.

Don

Imagine the 16 pin header of LCD display - a backlight LED is at the one end (pins 15,16) and pwr+gnd on the opposite (pins 1, 2) . Maybe you exchanged them ?

As you can see in the picture there al connectiosn have descriptions silkscreened.