Pages: [1]   Go Down
Author Topic: arduino mega and lcd HD44780  (Read 1907 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 25
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hello, I am new to the world of Arduino, I want to create a controller for my ramp led to my aquarium.
 First I need your help to connect my arduino to my mega HD44780 4x20 LCD. I use this screen:http://cgi.ebay.fr/LCD-Display-HD44780-4x20-chr-20x4-BLUE-neg-Backlight-/160574392993?pt=Bauteile&hash=item2562facaa1
 I can not connect properly and display text. For now I only have 2 lines (white square) and contrast that work
Logged

Western New York, USA
Offline Offline
Faraday Member
**
Karma: 36
Posts: 4303
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I can not connect properly and display text. For now I only have 2 lines (white square) and contrast that work
My guess is that these are lines 1 and 3 which would indicate that you have connected the power, contrast, and back light correctly but the LCD controller is not being initialized properly.  This could be the result of incorrect wiring or incorrect program code.

In order to help you we will have to see a photograph that clearly shows the connections between your Arduino and your LCD.  We will also have to see the sketch that you are actually using.  We do not need or want a link to the sketch that you are attempting to use.


Don
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 25
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

thank you for your help.
 I wired this way:

LCD  Arduino
 1 -> gnd
 2 -> +5 v
 3 -> middle potentiometer
 4 -> 36
 5 -> 35
 6 -> 37
 7 -> not used
 8 -> not used
 9 -> not used
 10 -> not used
 11 -> 26 pin
 12 -> 27 pin
 13 -> 28 pin
 14 -> 29 pin
 15 -> Contrast +5 v
 16 -> contrast Gnd

potar: +5v -- pin 3 lcd -- Gnd
Logged

Western New York, USA
Offline Offline
Faraday Member
**
Karma: 36
Posts: 4303
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

That doesn't help without the photograph and sketch.  

Don
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 25
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset



here's a photo of the first part of the wiring, I did not put the cable DB4 a7.
 On the left Gnd and +5 v V0 contrast yellow on the right Potar and Gnd and +5 v of the screen

 I tried to follow the post ladyada but the result is the same
« Last Edit: August 03, 2011, 01:45:59 am by razmo » Logged

Central MN, USA
Offline Offline
Tesla Member
***
Karma: 73
Posts: 7189
Phi_prompt, phi_interfaces, phi-2 shields, phi-panels
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I wired this way:

Oh I don't think so or did you have wires made of ether? You wired the first 3 and last 2 pins and missed all those in the middle. BTW, your image links sucked.

Follow this tutorial:

http://www.ladyada.net/learn/lcd/charlcd.html
Logged


Offline Offline
Newbie
*
Karma: 0
Posts: 25
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

grrrrr help me smiley-cry
Logged

Central MN, USA
Offline Offline
Tesla Member
***
Karma: 73
Posts: 7189
Phi_prompt, phi_interfaces, phi-2 shields, phi-panels
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

You wired the first 3 and last 2 pins and missed all those in the middle.

Is there anything unclear of what I said?

Starting from lcd pin 4 and ending at lcd pin 14, you didn't wire them to anything so why should it work?


The tutorial you followed is clear enough but you didn't follow it the entire way. You need to go back to it and find at which step you slipped away from it and resume.

If you can't understand some of the steps, you should point it out here so you can get helped. Grinding your teeth is not very useful  smiley-wink
Logged


Offline Offline
Newbie
*
Karma: 0
Posts: 25
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hello has all,

 I return towards you because I do not still arrive has cabler the ecran. I followed the tuto of ladyada has the letter and I can simply regler the contrast.
For reminder I use an arduino mega and I cable DB4 in 26, DB5 in 27, DB6 in 28, DB7 in 29, RS in 36 and Enable in 37
Logged

Central MN, USA
Offline Offline
Tesla Member
***
Karma: 73
Posts: 7189
Phi_prompt, phi_interfaces, phi-2 shields, phi-panels
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

What language is this in? What you posted is not understood.
Please use your native language and Google translate.
Did you or did you not connect lcd wires 4 to 14?
Logged


Minnesota USA
Offline Offline
Sr. Member
****
Karma: 1
Posts: 323
Made it mahself outta sand 'n wahr.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

to try to be as explicit as possible your picture clearly shows the arduino sockets 26-29 are not connected and pins 4-6 and 10-14 on the LCD are not connected.

If you do connect wires between these, then your sketch will need to change the line
Code:
LiquidCrystal lcd(36,35,37, 26,27,28,29);
Logged

Pages: [1]   Go Up
Jump to: