serial lcd module arduino quotation

I have an I2C OLED connected to my Arduino Uno and I have used it to display integers in past projects, but I would like to know how to place quotes around a variable (in this case Serial.read() ). My current solution displays strange characters around the text on the OLED, but if I use a constant non-changing variable the OLED doesn"t spit out a garbage character. Here"s my code:

In Arduino programming many times you will come with situations where you want to put double quotes in a string. For example sending AT command with double quotes. There many different methods let’s discuss one by one.

In this tutorial, I’ll explain how to set up an LCD on an Arduino and show you all the different ways you can program it. I’ll show you how to print text, scroll text, make custom characters, blink text, and position text. They’re great for any project that outputs data, and they can make your project a lot more interesting and interactive.

The display I’m using is a 16×2 LCD display that I bought for about $5. You may be wondering why it’s called a 16×2 LCD. The part 16×2 means that the LCD has 2 lines, and can display 16 characters per line. Therefore, a 16×2 LCD screen can display up to 32 characters at once. It is possible to display more than 32 characters with scrolling though.

The code in this article is written for LCD’s that use the standard Hitachi HD44780 driver. If your LCD has 16 pins, then it probably has the Hitachi HD44780 driver. These displays can be wired in either 4 bit mode or 8 bit mode. Wiring the LCD in 4 bit mode is usually preferred since it uses four less wires than 8 bit mode. In practice, there isn’t a noticeable difference in performance between the two modes. In this tutorial, I’ll connect the LCD in 4 bit mode.

Here’s a diagram of the pins on the LCD I’m using. The connections from each pin to the Arduino will be the same, but your pins might be arranged differently on the LCD. Be sure to check the datasheet or look for labels on your particular LCD:

Also, you might need to solder a 16 pin header to your LCD before connecting it to a breadboard. Follow the diagram below to wire the LCD to your Arduino:

All of the code below uses the LiquidCrystal library that comes pre-installed with the Arduino IDE. A library is a set of functions that can be easily added to a program in an abbreviated format.

In order to use a library, it needs be included in the program. Line 1 in the code below does this with the command #include . When you include a library in a program, all of the code in the library gets uploaded to the Arduino along with the code for your program.

Now we’re ready to get into the programming! I’ll go over more interesting things you can do in a moment, but for now lets just run a simple test program. This program will print “hello, world!” to the screen. Enter this code into the Arduino IDE and upload it to the board:

TheLiquidCrystal() function sets the pins the Arduino uses to connect to the LCD. You can use any of the Arduino’s digital pins to control the LCD. Just put the Arduino pin numbers inside the parentheses in this order:

This function sets the dimensions of the LCD. It needs to be placed before any other LiquidCrystal function in the void setup() section of the program. The number of rows and columns are specified as lcd.begin(columns, rows). For a 16×2 LCD, you would use lcd.begin(16, 2), and for a 20×4 LCD you would use lcd.begin(20, 4).

This function clears any text or data already displayed on the LCD. If you use lcd.clear() with lcd.print() and the delay() function in the void loop() section, you can make a simple blinking text program:

Similar, but more useful than lcd.home() is lcd.setCursor(). This function places the cursor (and any printed text) at any position on the screen. It can be used in the void setup() or void loop() section of your program.

The cursor position is defined with lcd.setCursor(column, row). The column and row coordinates start from zero (0-15 and 0-1 respectively). For example, using lcd.setCursor(2, 1) in the void setup() section of the “hello, world!” program above prints “hello, world!” to the lower line and shifts it to the right two spaces:

You can use this function to write different types of data to the LCD, for example the reading from a temperature sensor, or the coordinates from a GPS module. You can also use it to print custom characters that you create yourself (more on this below). Use lcd.write() in the void setup() or void loop() section of your program.

The function lcd.noCursor() turns the cursor off. lcd.cursor() and lcd.noCursor() can be used together in the void loop() section to make a blinking cursor similar to what you see in many text input fields:

Cursors can be placed anywhere on the screen with the lcd.setCursor() function. This code places a blinking cursor directly below the exclamation point in “hello, world!”:

This function creates a block style cursor that blinks on and off at approximately 500 milliseconds per cycle. Use it in the void loop() section. The function lcd.noBlink() disables the blinking block cursor.

This function turns on any text or cursors that have been printed to the LCD screen. The function lcd.noDisplay() turns off any text or cursors printed to the LCD, without clearing it from the LCD’s memory.

This function takes anything printed to the LCD and moves it to the left. It should be used in the void loop() section with a delay command following it. The function will move the text 40 spaces to the left before it loops back to the first character. This code moves the “hello, world!” text to the left, at a rate of one second per character:

Like the lcd.scrollDisplay() functions, the text can be up to 40 characters in length before repeating. At first glance, this function seems less useful than the lcd.scrollDisplay() functions, but it can be very useful for creating animations with custom characters.

lcd.noAutoscroll() turns the lcd.autoscroll() function off. Use this function before or after lcd.autoscroll() in the void loop() section to create sequences of scrolling text or animations.

This function sets the direction that text is printed to the screen. The default mode is from left to right using the command lcd.leftToRight(), but you may find some cases where it’s useful to output text in the reverse direction:

This code prints the “hello, world!” text as “!dlrow ,olleh”. Unless you specify the placement of the cursor with lcd.setCursor(), the text will print from the (0, 1) position and only the first character of the string will be visible.

This command allows you to create your own custom characters. Each character of a 16×2 LCD has a 5 pixel width and an 8 pixel height. Up to 8 different custom characters can be defined in a single program. To design your own characters, you’ll need to make a binary matrix of your custom character from an LCD character generator or map it yourself. This code creates a degree symbol (°):

Plus, what you were doing was probably a kind of code bending/or else, using brute force and think that will work. You just opened the bracket of serialprintfloat and copy+paste everything from a sample code inside and re-closed it, without reading the code. Very not cool.

First of all for you, have respect for those that made suggestions. The original programmer that wrote the serialprintfloat told you it"s old code so you should toss it and just do Serial.println(a_floating_point_number).

Strings are used to store text. They can be used to display text on an LCD or in the Arduino IDE Serial Monitor window. Strings are also useful for storing the user input. For example, the characters that a user types on a keypad connected to the Arduino.

In this chapter, we will learn Strings, objects and the use of strings in Arduino sketches. By the end of the chapter, you will learn which type of string to use in a sketch.

The following example shows what a string is made up of; a character array with printable characters and 0 as the last element of the array to show that this is where the string ends. The string can be printed out to the Arduino IDE Serial Monitor window by using Serial.println() and passing the name of the string.

This article includes everything you need to know about using acharacter I2C LCD with Arduino. I have included a wiring diagram and many example codes to help you get started.

Once you know how to display text and numbers on the LCD, I suggest you take a look at the articles below. In these tutorials, you will learn how to measure and display sensor data on the LCD.

Each rectangle is made up of a grid of 5×8 pixels. Later in this tutorial, I will show you how you can control the individual pixels to display custom characters on the LCD.

They all use the same HD44780 Hitachi LCD controller, so you can easily swap them. You will only need to change the size specifications in your Arduino code.

The 16×2 and 20×4 datasheets include the dimensions of the LCD and you can find more information about the Hitachi LCD driver in the HD44780 datasheet.

Note that an Arduino Uno with the R3 layout (1.0 pinout) also has the SDA (data line) and SCL (clock line) pin headers close to the AREF pin. Check the table below for more details.

After you have wired up the LCD, you will need to adjust the contrast of the display. On the I2C module, you will find a potentiometer that you can turn with a small screwdriver.

The LiquidCrystal_I2C library works in combination with the Wire.h library which allows you to communicate with I2C devices. This library comes pre-installed with the Arduino IDE.

To install this library, go to Tools > Manage Libraries (Ctrl + Shift + I on Windows) in the Arduino IDE. The Library Manager will open and update the list of installed libraries.

Note that counting starts at 0 and the first argument specifies the column. So lcd.setCursor(2,1) sets the cursor on the third column and the second row.

Next the string ‘Hello World!’ is printed with lcd.print("Hello World!"). Note that you need to place quotation marks (” “) around the text since we are printing a text string.

The example sketch above shows you the basics of displaying text on the LCD. Now we will take a look at the other functions of the LiquidCrystal_I2C library.

This function turns on automatic scrolling of the LCD. This causes each character output to the display to push previous characters over by one space.

I would love to know what projects you plan on building (or have already built) with these LCDs. If you have any questions, suggestions or if you think that things are missing in this tutorial, please leave a comment down below.

Bought this from Robotshop retailer. Worked right away like a charm. I even changed splash screen to display my software version. However at some point it stopped displaying text, then backlight started spontaneously switching off several seconds after powering on. I connected LCD to different device and started experimenting just sending one command at a time.

My only complaint with this product is the difficulty in mounting. Finally had to drill out the holes to accept 4-40 standoffs. The Eagle files don"t include the complete board so making a screw hole template from the PCB is impossible. Otherwise works fine with my stand alone Atmega 328P using the SerLCD.h and SoftwareSerial.h libraries.

Does anybody know how to do a hard reset on this LCD? While I was uploading my code, I left it plugged into TX, and it doesn"t work anymore. I"m realizing that it probably got spammed with commands and the configuration got messed up. Does anybody know how to reset to factory defaults?

I have the same question. I now have the 3.3v serial enabled LCD (with backpack) and want to use this one for future usage. VDD of 5V can be supplied, but will the TTL work when its getting 3.3V signals from the TX from Netduino?

Is it just me, or are the solder holes for VDD, GND, and TX near the JST connector too small to accept standard pin headers? Perhaps I just need to use a little more force? I see that one of the pictures of this module shows what appear to be standard headers installed in that location, so I am confused..

I"ve put together some python code for sending serial data to these LCD screens. In particular, the code pulls my twitter status and writes it to the LCD. To work with the extra characters, I wrote functions to page the text (vertical scroll) or scroll the text (horizontal scroll). Details are available here: http://dawes.wordpress.com/2009/12/23/twitter-to-lcd/

I spent more time today trying to use this to help in debugging an Arduino, than if I would have just soldered on a JTAG connector, installed linux, and used that.

Is it possible to wire this up in parrellel rather than use the serial function? I ran into a snag and am unable to use the serial function of this lcd? I see the pinouts on the schematic but when wired it doesn"t seem to work.

I"ve created a new splash screen for the Serial LCD, now I want to save it to the Serial LCD memory. So, exactly how do I write a "control-j" to the Serial LCD. I"ve put in the required line to transmit special character 124, but I can figure out how to format the "control-j" line of code. I"ve Googled this for about an hour and can"t find an explanation or sample code anywhere. Here"s my code...void setup() {

I"m not sure if you"re referring to comments on the website, or on your LCD screen. You can contact techsupport@ and they"ll be able to assist you further.

I have used a Labview program for this LCD. When i send character "a", the display is "0". Does anyone having a same problem. How should I troubleshoot this problem.Tq

Has anyone managed to get the PWM backlighting working with an Arduino? I"m trying variations of this and nothing works except the standard On/Off commands using 0xFE as the escape. All my attempts turn the display off but the backlight LED is on full.

Why do I get power out of the VDD port with only RX and GND hooked up? I have a 5V rail that I use to power everything on my board - and when I added this SerLCD I now have a bridge between the arduino power and my 5v line ... which I dont want. Can I add a diode to the VDD to stop reverse voltage from powering my board?

It seems like the MCLR function has been disabled through the config bits. No pullup to Vdd is installed. This makes it really irritating to work with this display. Programming an arduino with this hooked the HW serial port will screw up the display, and without the reset line you have to pull power. A simple solution would just be to wire the PICs MCLR pin to the Arduinos reset line, but this isn"t possible without the MCLR function obviously.

Quick suggestion... It"d be very helpful for some people if you guys added a note in the description pointing people to the correct 3-pin JST jumper wire to be used with these serial LCDs. Two reasons... it"s not clear that the jumper is not included, and you have 3-pin jumpers in your catalog which don"t work with this serial LCD.

I have ported LiquidCrystal library for use with the serial LCD you can look at my code here. Still working on finishing all the documentation. But putting up for now hopefully someone will find it usefull.

I"m also having the same problem after accidentally sending the control character "|" followed by "\", "-", "/" to the LCD as I was trying to animate a rotating bar to indicate a busy status.

Does the serial version of the display still have the parallel pins available on it? I would like to use the serial access for the most part, but I might need regular old parallel for one project.

I"m asking b/c I"m in a space constrained situation where the serial backpack just isn"t going to fit. The datasheet (2.5) shows a picture with a backpack (soldered on?), but nothing else on this page suggests that any backpack is required to talk with this device thru 3-wire serial.

I"m asking b/c I"m in a space constrained situation where the serial backpack just isn"t going to fit. The datasheet (2.5) shows a picture with a backpack (soldered on?), but nothing else on this page suggests that any backpack is required to talk with this device thru 3-wire serial.

Having ordered this exact LCD myself, I can say that aside from the issue mentioned in my other comment, it looks exactly like the picture. No bulky backpack module, everything is on a single board. Pretty sleek, really.

I used a few of these in my IRcombat laser tag game with my arduino duemiloves and love them. I also used the Red and Black. I like the white and black better outdoors and the red/black indoors. I just wish I could figure out how to send the reset code to them. I know how to clear and change brightness in code, but the ctrl+ command boggles my mind. A few of them have to be unplugged and plugged back in to work after power on because of this issue. Not worth replacing them yet.

Hi...noob question. how do i send data on the fly via arduino? it only has 1 connection to tx. i tried using the serial monitor to send something, but it doesnt work...im looking for something which i guess is similar to liquidCrystal->SerialDisplay example.

I have a couple of suggestions for a future version: On the PCB layout, please add a thermal to the ground pin for the user connectors to make it easier to hand solder. Please change the firmware to make it more difficult for a random serial stream to stumble upon a configuration sequence. Maybe pick a non-printable prefix character like ESC instead of the vertical bar. Please make the brightness values more user friendly, like 1, 2, 3, etc. Maybe have an option to make the display scroll when it gets full, instead of resetting the cursor to home and overwriting. All-in-all, a fun little platform. Thanks for using a PIC on this one! I think I may try my hand at writing some new firmware for it. Cheers!

Edit: Got mine fixed. If you checked the soldering on all the terminals, check them again. I also sometimes was getting strings of garbage if I wriggled the terminals on the LCD (I suspect because I was getting a partial connection on the bad terminal). Resoldered and it is working fine now.

Wait, so I get the 3 pins for power and control, but whats with all the other pins on the sides? Can it be used to control another LCD besides the one built in?

The other pins are used if you want to control the LCD without using the serial standard. There"s some tutorials on how to do that with the arduino below. You have more control over what you can do with it, but it takes up more pins on the arduino. If you want to wire it up this way, don"t spend the money on the serial interface, they have cheaper LCD"s that allow you to do it this way, without the serial.

The IO-204 has two ways to output serial - one directly out of a channel and the other is thru a serial smart board. If you see "SO=" then the widget was using the smart board protocol. Using a Serial Out widget under "I/O Channel Widgets". I hope that helps out.

Generally, strings are terminated with a null character (ASCII code 0). This allows functions (like Serial.print()) to tell where the end of a string is. Otherwise, they would continue reading subsequent bytes of memory that aren"t actually part of the string.

This means that your string needs to have space for one more character than the text you want it to contain. That is why Str2 and Str5 need to be eight characters, even though "arduino" is only seven - the last position is automatically filled with a null character. Str4 will be automatically sized to eight characters, one for the extra null. In Str3, we"ve explicitly included the null character (written "\0") ourselves.

It is often convenient, when working with large amounts of text, such as a project with an LCD display, to setup an array of strings. Because strings themselves are arrays, this is in actually an example of a two-dimensional array.

Strings, objects and how to use strings in Arduino sketches are fully explained in this part of the Arduino programming course. The question of which type of sting to use in a sketch is answered at the end of this article.

Getting the length of the string is easily done by using length(). In the example sketch, the result returned by length() is passed directly to Serial.println() without using an intermediate variable.

A String object is much easier to use than a string character array. The object has built-in functions that can perform a number of operations on strings which are fully documented in the reference section on the Arduino website.

The main disadvantage of using the String object is that it uses a lot of memory and can quickly use up the Arduino"s RAM memory which may cause the Arduino to hang, crash or produce unexpected behaviour. This is especially true for the smaller Arduinos such as the Arduino Uno.

Actual practical uses of strings will be covered in the next part of this course when we look at how to get user input from the Serial Monitor window and save the input in a string.