how to test lcd display 16x2 pricelist
Do you want your Arduino projects to display status messages or sensor readings? Then these LCD displays can be a perfect fit. They are extremely common and fast way to add a readable interface to your project.
This tutorial will help you get up and running with not only 16×2 Character LCD, but any Character LCD (16×4, 16×1, 20×4 etc.) that is based on Hitachi’s LCD Controller Chip – HD44780.
When current is applied to these crystals, they become opaque, blocking the backlight that resides behind the screen. As a result that particular area will be dark compared to the others. And this is how the characters are displayed on the screen.
True to their name, these LCDs are ideal for displaying only text/characters. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows of 16 characters each.
If you look closely you can see tiny rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.
The good news is that all of these displays are ‘swappable’, which means if you build your project with one you can just unplug it and use another size/color LCD of your choice. Your code will have to change a bit but at least the wiring remains the same!
Vo (LCD Contrast) controls the contrast and brightness of the LCD. Using a simple voltage divider with a potentiometer, we can make fine adjustments to the contrast.
RS (Register Select) pin is set to LOW when sending commands to the LCD (such as setting the cursor to a specific location, clearing the display, etc.) and HIGH when sending data to the LCD. Basically this pin is used to separate the command from the data.
R/W (Read/Write) pin allows you to read data from the LCD or write data to the LCD. Since we are only using this LCD as an output device, we are going to set this pin LOW. This forces it into WRITE mode.
E (Enable) pin is used to enable the display. When this pin is set to LOW, the LCD does not care what is happening on the R/W, RS, and data bus lines. When this pin is set to HIGH, the LCD processes the incoming data.
D0-D7 (Data Bus) pins carry the 8 bit data we send to the display. For example, if we want to see an uppercase ‘A’ character on the display, we set these pins to 0100 0001 (as per the ASCII table).
Now we will power the LCD. The LCD has two separate power connections; One for the LCD (pin 1 and pin 2) and the other for the LCD backlight (pin 15 and pin 16). Connect pins 1 and 16 of the LCD to GND and 2 and 15 to 5V.
Most LCDs have a built-in series resistor for the LED backlight. You’ll find this near pin 15 on the back of the LCD. If your LCD does not include such a resistor or you are not sure if your LCD has one, you will need to add one between 5V and pin 15. It is safe to use a 220 ohm resistor, although a value this high may make the backlight a bit dim. For better results you can check the datasheet for maximum backlight current and select a suitable resistor value.
Next we will make the connection for pin 3 on the LCD which controls the contrast and brightness of the display. To adjust the contrast we will connect a 10K potentiometer between 5V and GND and connect the potentiometer’s center pin (wiper) to pin 3 on the LCD.
That’s it. Now turn on the Arduino. You will see the backlight lit up. Now as you turn the knob on the potentiometer, you will start to see the first row of rectangles. If that happens, Congratulations! Your LCD is working fine.
Let’s finish connecting the LCD to the Arduino. We have already made the connections to power the LCD, now all we have to do is make the necessary connections for communication.
We know that there are 8 data pins that carry data to the display. However, HD44780 based LCDs are designed in such a way that we can communicate with the LCD using only 4 data pins (4-bit mode) instead of 8 (8-bit mode). This saves us 4 pins!
8-bit mode is much faster than 4-bit mode because it takes half the time. In 8-bit mode you write the data in one go. Whereas in 4-bit mode you have to split a byte into 2 nibbles and perform two write operations.
4-bit mode is often used to save I/O pins. However, 8-bit mode is best used when speed is required in an application and there are at least 10 I/O pins available.
The sketch begins by including the LiquidCrystal library. The Arduino community has a library called LiquidCrystal which makes programming of LCD modules less difficult. You can find more information about the library on Arduino’s official website.
First we create a LiquidCrystal object. This object uses 6 parameters and specifies which Arduino pins are connected to the LCD’s RS, EN, and four data pins.
In the ‘setup’ we call two functions. The first function is begin(). It is used to specify the dimensions (number of columns and rows) of the display. If you are using a 16×2 character LCD, pass the 16 and 2; If you’re using a 20×4 LCD, pass 20 and 4. You got the point!
After that we set the cursor position to the second row by calling the function setCursor(). The cursor position specifies the location where you want the new text to be displayed on the LCD. The upper left corner is assumed to be col=0, row=0.
There are some useful functions you can use with LiquidCrystal objects. Some of them are listed below:lcd.home() function is used to position the cursor in the upper-left of the LCD without clearing the display.
lcd.scrollDisplayRight() function scrolls the contents of the display one space to the right. If you want the text to scroll continuously, you have to use this function inside a for loop.
lcd.scrollDisplayLeft() function scrolls the contents of the display one space to the left. Similar to above function, use this inside a for loop for continuous scrolling.
If you find the characters on the display dull and boring, you can create your own custom characters (glyphs) and symbols for your LCD. They are extremely useful when you want to display a character that is not part of the standard ASCII character set.
As discussed earlier in this tutorial a character is made up of a 5×8 pixel matrix, so you need to define your custom character within that matrix. You can use the createChar() function to define a character.
To use createChar() you first set up an array of 8 bytes. Each byte in the array represents a row of characters in a 5×8 matrix. Whereas, 0 and 1 in a byte indicate which pixel in the row should be ON and which should be OFF.
CGROM is used to store all permanent fonts that are displayed using their ASCII codes. For example, if we send 0x41 to the LCD, the letter ‘A’ will be printed on the display.
CGRAM is another memory used to store user defined characters. This RAM is limited to 64 bytes. For a 5×8 pixel based LCD, only 8 user-defined characters can be stored in CGRAM. And for 5×10 pixel based LCD only 4 user-defined characters can be stored.
Creating custom characters has never been easier! We have created a small application called Custom Character Generator. Can you see the blue grid below? You can click on any 5×8 pixel to set/clear that particular pixel. And as you click, the code for the character is generated next to the grid. This code can be used directly in your Arduino sketch.
Your imagination is limitless. The only limitation is that the LiquidCrystal library only supports eight custom characters. But don’t be discouraged, look at the bright side, at least we have eight characters.
In setup we need to create custom character using createChar() function. This function takes two parameters. The first parameter is a number between 0 and 7 to reserve one of the 8 supported custom characters. The second is the name of the array.
The CFA533-***-KC series is a 16x2 I2C LCD with keypad. The I2C interface allows you to use just two lines (SDA & SCL) to have bi-directional communication with the I2C LCD. Other devices can also share those two I2C control lines with the LCD. Only 4 wires are needed to connect this I2C LCD: power, ground, SDA (I2C Serial DAta) and SCL (I2C Serial CLock).
The CFA533 can run on 3.3v to 5.0v directly, with no changes needed, so you do not need to do any level translation between your embedded processor and the I2C LCD. Simply power the CFA533 from the same supply as your processor and the I2C signal levels will match up.
Using only one address on your I2C bus, you can add all the elements that you need for your front panel. The CFA533 I2C LCD can also read up to 32 DS18B20 digital temperature sensors, giving you an easy way to integrate temperature sensing over the I2C bus. No additional firmware or pins are needed on the host system.
This CFA533-TFH variant features crisp dark letters against a white, backlit background. The keypad has a matching white LED backlight. Since the LCD is a backlit positive FSTN, the CFA533-TFH I2C LCD is readable in direct sunlight, as well as complete darkness.
A few weeks ago, we examined the features of ESP32 module and built a simple hello world program to get ourselves familiar with the board. Today, we will continue our exploration of the ESP32 on a higher level as we will look at how to interface a 16×2 LCD with it.
Displays provide a fantastic way of providing feedback to users of any project and with the 16×2 LCD being one of the most popular displays among makers, and engineers, its probably the right way to start our exploration. For today’s tutorial, we will use an I2C based 16×2 LCD display because of the easy wiring it requires. It uses only four pins unlike the other versions of the display that requires at least 7 pins connected to the microcontroller board.
ESP32 comes in a module form, just like its predecessor, the ESP-12e, as a breakout board is usually needed to use the module. Thus when it’s going to be used in applications without a custom PCB, it is easier to use one of the development boards based on it. For today’s tutorial, we will use the DOIT ESP32 DevKit V1 which is one of the most popular ESP32 development boards.
The schematics for this project is relatively simple since we are connecting just the LCD to the DOIT Devkit v1. Since we are using I2C for communication, we will connect the pins of the LCD to the I2C pins of the DevKit. Connect the components as shown below.
Due to the power requirements of the LCD, it may not be bright enough when connected to the 3.3v pin of the ESP32. If that is the case, connect the VCC pin of the LCD to the Vin Pin of the ESP32 so it can draw power directly from the connected power source.
At this point, it is important to note that a special setup is required to enable you to use the Arduino IDE to program ESP32 based boards. We covered this in the introduction to ESP32 tutorial published a few weeks go. So, be sure to check it out.
To be able to easily write the code to interact with the I2C LCD display, we will use the I2C LCD library. The Library possesses functions and commands that make addressing the LCD easy. Download the I2C LCD library from the link attached and install on the Arduino IDE by simply extracting it into the Arduino’s library folder.
Before writing the code for the project, it’s important for us to know the I2C address of the LCD as we will be unable to talk to the display without it.
While some of the LCDs come with the address indicated on it or provided by the seller, in cases where this is not available, you can determine the address by using a simple sketch that sniffs the I2C line to detect what devices are connected alongside their address. This sketch is also a good way to test the correctness of your wiring or to determine if the LCD is working properly.
This sketch basically uses a “for” loop to generate a list of addresses and then sends a begin transmission request to the address. The return value of the Write.endTransmission() function shows if a device exists on that particular address. The address at which a response was received is the address we are a looking for.
If you keep getting “no devices found”, it might help to take a look at the connections to be sure you didn’t mix things up and you could also go ahead and try 0x27 as the I2C address. This is a common address for most I2C LCD modules from China.
Our task for today’s tutorial is to display both static and scrolling text on the LCD, and to achieve that, we will use the I2C LCD library to reduce the amount of code we need to write. We will write two separate sketches; one to displaystatic textsand the other to display both static and scrolling text.
To start with the sketch for static text display, we start the code by including the library to be used for it, which in this case, is the I2C LCD library.
Next, we create an instance of the I2C LCD library class with the address of the display, the number of columns the display has (16 in this case), and the number of rows (2 in this case) as arguments.
With that done, we proceed to the void setup() function. Here we initialize the display and issue the command to turn the backlight on as it might be off by default depending on the LCD.
Next is the void loop() function. The idea behind the code for the loop is simple, we start by setting the cursor to the column and row of the display where we want the text to start from, and we proceed to display the text using the lcd.print() function. To allow the text to stay on the screen for a while (so its visible) before the loop is reloaded, we delay the code execution for 1000ms.
For the scrolling text, we will use some code developed by Rui Santos of RandomNerdTutorials.com. This code allows the display of static text on the first row and scrolling text on the second row of the display at the same time.
Next, we create an instance of the I2C LCD library class with the address of the display, the number of columns the display has (16 in this case), and the number of rows (2 in this case) as arguments.
Next, we create the function to display scrolling text. The function accepts four arguments; the row on which to display the scrolling text, the text to be displayed, the delay time between the shifting of characters, and the number of columns of the LCD.
Next is the void setup() function. The function stays the same as the one for the static text display as we initialize the display and turn on the backlight.
With that done, we move to the void loop() function. We start by setting the cursor, then we use the print function to display the static text and the scrollText() function is called to display the scrolling text.
Ensure your connections are properly done, connect the DOIT Devkit to your PC and upload either of the two sketches. You should see this display come up with the text as shown in the image below.
That’s it for today’s tutorial guys. Thanks for following this tutorial. This cheap LCD display provides a nice way of providing visual feedback for your project and even though the size of the screen and the quality of the display is limited, with the scrolling function you can increase the amount of text/characters that can be displayed.
ERMC1602SBS-2 is 16 characters wide,2 rows character lcd module,SPLC780C controller (Industry-standard HD44780 compatible controller),6800 4/8-bit parallel interface,single led backlight with white color included can be dimmed easily with a resistor or PWM,stn- blue lcd negative,white text on the blue color,wide operating temperature range,rohs compliant,built in character set supports English/Japanese text, see the SPLC780C datasheet for the full character set. It"s optional for pin header connection,5V or 3.3V power supply and I2C adapter board for arduino.
Of course, we wouldn"t just leave you with a datasheet and a "good luck!".For 8051 microcontroller user,we prepared the detailed tutorial such as interfacing, demo code and Development Kit at the bottom of this page.
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Since the use of an LCD requires many microcontroller pins, we will reduce that number using serial communication, which is basically sending "packages" of data one after another, using only two pins of our microcontroller , pins SDA and SCL which are the analog pins A4 and A5 of the Arduino NANO or pro mini.
First of all we connect i2c pins module as shown in the schematic. Power the LCD module to 5 volts and connect the ground as well. The SDA pin of the i2c module conected to arduinio A5 and the SCL pin to A4. We connect the arduino to USB and we are ready to program. In order to make the LCD work we need to inport the LCD library for arduino.
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Want to change the colour of the text on your display, on the fly? This Adafruit display gives you the flexibility of the RGB spectrum on a single LCD! But to do so, many, many I/O pins give their life to the function. 6 controlling the LCD, and another 3 control the RGB. That uses up half of the pins available on a classic Arduino!
Solution: Take this 16×2 Character LCD, with the 3 backlight pins AND 5 keypad pins, and link them all together so you use only the two I2C pins on the Arduino! The best part is you don’t really lose those two pins either, since you can stick i2c-based sensors, RTCs, etc and have them share the I2C bus. This is a super slick way to add a display without all the wiring hassle.
This shield is perfect for when you want to build a stand-alone project with its own user interface. The 4 directional buttons plus select button allows basic control without having to attach a bulky computer.
The shield is designed for ‘classic’ Arduinos such as the Uno, Duemilanove, Diecimila, etc. It will also work perfectly with Arduino Mega R3’s. Earlier Mega’s have the I2C pins in a different location and will require you to solder two wires from the I2C pins on the shield and plug them into the different I2C locations at Digital 20 & 21.
This product comes as a kit! Included is a high quality, USA-made PCB and all the components (buttons, header etc). This product comes with a 16×2 RGB positive. Assembly is easy, even if you’ve never soldered before and the kit can be completed in 30 minutes. Check the product tutorial page for assembly instructions before purchasing.
Of course, we even wrote an easy-to-use Arduino library that you can easily add to your project. It acts just like the built in LiquidCrystal library, but automatically uses the shield pins. You can also easily query the 5 keypad buttons to get input through the library, so you get extra buttons without using any more pins.
At this time, the library and shield can control the RGB backlight of our character LCDs by turning each LED on or off. This means you can display the following colors: Red, Yellow, Green, Teal, Blue, Violet, White and all off. There is no support for PWM control of the backlight at this time, so if you need to have more granular control of the RGB backlight to display a larger range of colors, this shield can’t do that (the I2C expander does not have PWM output).
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We come across Liquid Crystal Display (LCD) displays everywhere around us. Computers, calculators, television sets, mobile phones, and digital watches use some kind of display to display the time.
An LCD screen is an electronic display module that uses liquid crystal to produce a visible image. The 16×2 LCD display is a very basic module commonly used in DIYs and circuits. The 16×2 translates a display of 16 characters per line in 2 such lines. In this LCD, each character is displayed in a 5×7 pixel matrix.
Contrast adjustment; the best way is to use a variable resistor such as a potentiometer. The output of the potentiometer is connected to this pin. Rotate the potentiometer knob forward and backward to adjust the LCD contrast.
Sends data to data pins when a high to low pulse is given; Extra voltage push is required to execute the instruction and EN(enable) signal is used for this purpose. Usually, we set en=0, when we want to execute the instruction we make it high en=1 for some milliseconds. After this we again make it ground that is, en=0.
A 16X2 LCD has two registers, namely, command and data. The register select is used to switch from one register to other. RS=0 for the command register, whereas RS=1 for the data register.
Command Register: The command register stores the command instructions given to the LCD. A command is an instruction given to an LCD to do a predefined task. Examples like:
Data Register: The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. When we send data to LCD, it goes to the data register and is processed there. When RS=1, the data register is selected.
Generating custom characters on LCD is not very hard. It requires knowledge about the custom-generated random access memory (CG-RAM) of the LCD and the LCD chip controller. Most LCDs contain a Hitachi HD4478 controller.
CG-RAM is the main component in making custom characters. It stores the custom characters once declared in the code. CG-RAM size is 64 bytes providing the option of creating eight characters at a time. Each character is eight bytes in size.
CG-RAM address starts from 0x40 (Hexadecimal) or 64 in decimal. We can generate custom characters at these addresses. Once we generate our characters at these addresses, we can print them by just sending commands to the LCD. Character addresses and printing commands are below.
LCD modules are very important in many Arduino-based embedded system designs to improve the user interface of the system. Interfacing with Arduino gives the programmer more freedom to customize the code easily. Any cost-effective Arduino board, a 16X2 character LCD display, jumper wires, and a breadboard are sufficient enough to build the circuit. The interfacing of Arduino to LCD display is below.
The combination of an LCD and Arduino yields several projects, the most simple one being LCD to display the LED brightness. All we need for this circuit is an LCD, Arduino, breadboard, a resistor, potentiometer, LED, and some jumper cables. The circuit connections are below.