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1  Using Arduino / Displays / Re: LCD Issues on: April 23, 2014, 09:54:30 pm
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Alrighty, Here is the code. Im also doing some stuff with float switches and stuff and all that works fine.
Let me take a wild guess ... the 'stuff' includes a valve, a pump, or some other electromagnetic device.

Don
2  Using Arduino / Displays / Re: Use serial LCD without Tx pin on: April 23, 2014, 07:08:44 am
SPI does not use the Tx or Rx pins.

Don
3  Using Arduino / Displays / Re: atmega328 + LCD 16x2 - nothing shows in void loop on: April 22, 2014, 06:43:30 pm
It's not getting to any of the lcd.clear statements which means that it is probably hanging up in one of your radio routines. 

You are going to have to do some troubleshooting to find out where.  Some additional strategically placed serial.print statements may help.


Don
4  Using Arduino / Displays / Re: Use serial LCD without Tx pin on: April 22, 2014, 10:52:29 am
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Hello, can I use serial LCD without using Tx pin on arduino?
Can you be more specific about which 'serial LCD' you plan to use. 

Most likely you are actually using or planning to use a serial adapter with a conventional parallel LCD module.  Most of the currently popular serial adapters use I2C which does not use Tx or Rx.


Don
5  Using Arduino / Displays / Re: LCD Configuration on: April 21, 2014, 02:04:23 pm
You can connect any of the LCD control and data pins to any available Arduino I/O pin.  All you have to do is make sure that the connections you use agree with the list in the LiquidCrystal lcd(...); constructor.  Either change the connections to agree with the constructor argument or change the constructor argument to agree with the connections.

Code:
//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here

The information is nicely buried here:  http://arduino.cc/en/Reference/LiquidCrystalConstructor

Don

6  Using Arduino / Displays / Re: atmega328 + LCD 16x2 - nothing shows in void loop on: April 21, 2014, 08:28:59 am
I have never used, or seen anybody else use lcd.display() or lcd.nodisplay() before and I really don't understand why you are using it here.

That command seems to allow you to either display a specific message or not display that same message without the need to re-write it each time you want to display it.

In your case you are immediately writing a new message immediately after restoring the old one but, as was implied in the preceding  answer, the new message is appended to the old one.  So at least at some point you are going to be sending information to locations that are not visible on your 16x2 display.


Don
7  Using Arduino / Displays / Re: lcd problem? on: April 20, 2014, 10:04:46 am
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i connected it as shown in the diagram and ran this code but got no response
You have shown us a copy of the code that you should be running and a copy of a diagram showing how you should connect the circuit.  See my final comment below the troubleshooting section below.

Here is my generic step by step approach that should work:

(1) If the module has a backlight then get it working properly.  This involves only pins 15 and 16 on most LCD modules.  Make sure to use a current limiting resistor if there is none on the LCD module.

(2) Get the power and contrast working properly.  This involves only pins 1, 2, and 3 on most LCD modules.  You should be able to just barely see blocks on one row of a two row display and on two rows of a four row display. 

NOTE:  The Arduino has not been used yet, except as a possible source for the power needed for the first two steps.  Do not try to go any further until this is working.  If you don't see the blocks then no amount of program code will help.

(3) Connect the LCD R/W pin (pin 5) to GND.

(4) Connect the six control and data wires between your LCD module and your Arduino.

(5) Upload your sketch and it should work.


Troubleshooting:

If you have a 16x1 display and there are blocks only on the left half of the row in step 2 then use lcd.begin(8, 2); in your sketch.

If you still don't get a display then make sure that your wiring matches the numbers in the descriptor (or vice versa).


Code:
//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here

If you get a display but it is garbled or has some other problems then try again with a 'static' sketch, one that displays a simple message on the top row of the display and then stops.  All of your code should be in setup() and loop() should be empty between the brackets.

Code:
#include <LiquidCrystal.h>

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here

void setup()
  {
  lcd.begin(16, 2);                          // put your LCD parameters here
  lcd.print("hello, world!");
  lcd.setCursor(0,1);
  lcd.print("it works!");
  }

void loop()
  {
  }

If you are still having problems then we need to see a photograph of your setup that clearly and unambiguously shows all of the connections between your Arduino and your LCD module.  We also need a copy/paste version of the code that you are actually using, not a link to the code that you think you are using.

Don
8  Using Arduino / Displays / Re: LCD Display 16X2 needs the Arduino Board to be reset now and then on: April 20, 2014, 09:57:19 am
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The arduino is driving 3 relays which switch on/off a pump (220 VAC) and a power supply (220 VAC) .   Could there be an interference problem, though this is unlikely since the remainder of the circuit (except the LCD) is working perfectly.
This is most likely the cause of your problem.  There have been lots of fairly recent posts dealing with similar erratic operation when relays and/or motors are involved.

Some things to look into:
How are you powering your relays? 
Do the relays have diodes across their coils?
How long are the wires leading from the Arduino to the LCD and how are they routed?
Are there extra bypass/decoupling capacitors on your power leads?


Don
9  Using Arduino / Displays / Re: Problem with LIQUIDCRYSTAL LIBRARY print on: April 19, 2014, 08:57:10 am
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Now, I set the cursor to bottom right corner, turn on auto scroll . and print the data.
. . .
My motive is to print the characters one after the other.
The normal operation of the display controller is the print the characters, one after the other, starting at the upper left.  This will be OK for the first 16 characters.

After each 16 characters you will have to do some cursor positioning.  I don't think that the auto scroll (which is really auto shift) will help you too much because after a while the 'old' characters will start to reappear on the screen.

Follow the LCD Addressing link at http://web.alfredstate.edu/weimandn for more information on the display characteristics.


Don
10  Using Arduino / Displays / Re: Help Needed in lcd JHD 162A interfacing with arduino2560 on: April 18, 2014, 09:08:56 am
Hi Friends.. when i connect my JHD 162A lcd with arduino2560 i just want to test contrast but it not working i connect pot with pin 3 and also use led to cnfirm thats the pot is working. pot work good but contrast not changed  smiley-sad-blue

any suggestion??
My first suggestion would be for you to rewrite your post using coherent sentences.
Explain how you have connected your potentiometer and explain just how you used an LED to confirm that the pot is working.


Don
11  Using Arduino / Displays / Re: LCD Display 16X2 needs the Arduino Board to be reset now and then on: April 18, 2014, 09:04:51 am
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Any help please
It's a little tough to help without seeing the code that is causing the problem.

Don
12  Using Arduino / Displays / Re: ecran B0802A on: April 16, 2014, 11:47:37 am
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Hello
I want to display information on the screen that I just bought but I do not. I searched a lot on the internet but mine is a 8 * 2 character which is not common.

    So I do not really know how to connect. (pin 1 to 14) ...

                                                            thank you

The connections are exactly the same as for the 16x2. 

In the program change   lcd.begin(16, 2);  ==>    lcd.begin(8, 2);


Don
13  Using Arduino / Displays / Re: Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 10:12:36 pm
You aren't providing much information.  Are you sure that the current drain of the backlight isn't causing your supply voltage to sag?

Don
14  Using Arduino / Displays / Re: Help w/ Display (Drivers SPLC780D OR ST7066U) on: April 14, 2014, 09:20:35 pm
According to the data sheet that you linked to this is a 3.3v device.  Have you taken that into account?

Don
15  Using Arduino / Displays / Re: I2C Display issues, can't get it to work... on: April 14, 2014, 01:09:17 pm
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Hi, I purchased an I2C display from eBay.
You might have better luck if you get a bit more specific.

Have you looked at any of the other forum posts concerning I2C LCD adapters?


Don
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