im nt getting any word on lcd ,jst lots of dots on 2nd raw

Hey Guy's
Im trying to interface 16*2 lcd with arduino uno board.. But im not getting any word on lcd..jst getting a Dots on 2nd row ,nothing on 1st row.
Every connection is right..
Then how this error is occur???

Did you solder it yourself?
And: are you sure about having selected the correct pins with the library?
Pls show us your code - using code tags </>

Your display is upside down, and the connections are not right.
Since you are able to take pictures, please take pictures showing what wires are connected to where, and show your code. If you want help.

Every connection is right.

I think I have heard that before!


The display shows that pattern when it is first powered up and has not been configured by the library using the control and data lines.

The good news is the you have the display powered correctly and the backlight working. There will be 6 more connections to data pins that you need to get exactly right as shown in this example here. Some pins will not be suitable for this (pins 0 and 1 on an UNO as they are used for the serial port).

You also need to setup the right pins in the sketch, see example here, otherwise the display will not get configured. It is critical that the pin order is correct.

Check solder joints are OK, no shorts between pins and nice clean wetted joints.

It looks like you are trying to use a single resistor, not a pot. as in diagram above to set the contrast. You should use a pot, but that is your next problem when you have the interface working.

Hi @rpt007
Yeah i was soldered with the male Buck stick..
When i was brought the lcd ,there are no connected ,so im soldier the Buck stick on bottom of lcd..

but it was difficult to connection on bottom im desolder it,and soldering it on top side.
But there is small problem ,while im soldering the pad of D7 was broken ,i thik tht is not prblm ,bcs pin is also connected on bottom..

Im checked many circuit diagram of connection, and connected as per i think tht is not issue of connection.

Im uploaded the code frm example>led>helloword
(Ardino 1.6.5) and also tried with (1.6.0)
But it's was occurs.

Im not USED I2C

You photo shows "reasonable soldering". It also shows you all the pin connections.

Just connect it like Bodmer's diagram in message #4.

Unsoldering is NEVER a good idea. It is easy to break the copper traces. Test all the connections with a multimeter. Repair with a soldering iron if necessary.



Im already checked the connection, as tht diagram n also checked all connection using multimeter

But still not working..

I have doubt tht the pin D7's pad was broken while im unsolder it..

So can i use D0-D3 pin in place of D4-D7???

Im already checked the connection, as tht diagram n also checked all connection using multimeter

Who has checked to make sure that you haven't connected it 'exactly wrong'. That is using pins 16 --> 1 instead of 1 --> 16?

So can i use D0-D3 pin in place of D4-D7???



No, you can NOT.

You should be able to see where the D7 header pin goes to. i.e. just follow the copper traces on the bottom of the LCD pcb.

Visually inspect your soldering. Is it bright and shiny with nice "wetting" of the terminal ?

With your DMM, check the connection between D7 header pin and a "plate-through" hole on the pcb. i.e. where a painted copper trace comes to a tiny gold circle with a hole in the middle.

Check all your header pins. Especially if you think you have damaged things with your unsoldering.

Then check the connectivity between the LCD header pins and the AVR when it is plugged into your breadboard.


Ok i will try solder it again..


Srry im not getting ur point.!!

post the wiring here.

Ensure the 10kohm rheostat is connected and lcd pin 5 is connected to the ground.

U can see the connection pic in ans of domber

i just saw it....but why don't you use the potential meter alone rather than resistors direct...?

Thank u,thank u so much guys
Finally the problem is solved

Really tht was the very silly problem..:stuck_out_tongue:
Actually during the resoldering D7 pad was broke as i told u earlier..

So im resolder at bottom side n it's working...:slight_smile:

Again tysm guys for help me


Congratulation that you made it eventually.
If you are not experienced in soldering and might also have not the best solder iron, soldering an lcd display is always a challenge and a hot spot - maybe I should say cold spot - for causing trouble.

RIGHT rpt007
And thank u