4x20 lcd display datasheet free sample

Newhaven 20x4 character Liquid Crystal Display shows characters with dark pixels on a bright yellow/green background when powered on. This transflective LCD Display is visible with ambient light or a backlight while offering a wide operating temperature range from -20 to 70 degrees Celsius. This NHD-0420AZ-FL-YBW-33V3 display has an optimal view of 6:00. This display operates at 3.3V supply voltage and is RoHS compliant.

Easily modify any connectors on your display to meet your application’s requirements. Our engineers are able to perform soldering for pin headers, boxed headers, right angle headers, and any other connectors your display may require.

Choose from a wide selection of interface options or talk to our experts to select the best one for your project. We can incorporate HDMI, USB, SPI, VGA and more into your display to achieve your design goals.

Newhaven 20x4 character Liquid Crystal Display shows characters with white pixels on a blue background when powered on. This transmissive LCD Display requires a backlight for visibility while offering a wide operating temperature range from -20 to 70 degrees Celsius. This NHD-0420DZ-NSW-BBW display has an optimal view of 6:00. This display operates at 5V supply voltage and is RoHS compliant.

Easily modify any connectors on your display to meet your application’s requirements. Our engineers are able to perform soldering for pin headers, boxed headers, right angle headers, and any other connectors your display may require.

Choose from a wide selection of interface options or talk to our experts to select the best one for your project. We can incorporate HDMI, USB, SPI, VGA and more into your display to achieve your design goals.

The Parallax Serial LCDs (liquid crystal displays) can be easily connected to and controlled by a microcontroller using a simple serial protocol sent from a single I/O pin. The LCD displays provide basic text wrapping so that your text looks correct on the display. Full control over all of their advanced LCD features allows you to move the cursor anywhere on the display with a single instruction and turn the display on and off in any configuration. They support visible ASCII characters Dec 32-127). In addition, you may define up to eight of your own custom characters to display anywhere on the LCD. An onboard piezospeaker provides audible output, with full control over tone note, scale and duration using ASCII characters Dec 208–232.

The LCDs currently for sale are updated to Revision F. Basic functionality remains the same, but power requirements and the layout of the backpack have changed. Please see the documentation for information on your model.

ERM2004SYG-2 is 20 characters wide,4 rows character lcd module,SPLC780C controller (Industry-standard HD44780 compatible controller),6800 4/8-bit parallel interface,single led backlight with yellow green color included can be dimmed easily with a resistor or PWM,stn-lcd positive,dark blue text on the yellow green 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.

Out of boredom I figured out I"ll write a library from scratch to interface the character LCD display which I got from ebay, quite cheap. Less than 7 pounds. However, I have written before a simple code to interface an LCD from scratch for 8051. So I have some experience and understanding how the character LCD works. The difference now will be, I" ll be using 4 bits, instead of 8 bits to communicate and read the busy flag. Essentially improving the previous code. I chose to write it for Arduino this time, because I have Sanguinololu bought for my 3D printer, and at some point I want to write a LCD user interface for it, from scratch. There won"t be anything spectacular about this tutorial, there are already good articles about this stuff for all kinds of devices. Moreover, arduino has bunch of LCD libraries available for download for free. BUT... in this tutorial I"ll describe problems I encountered and try to be as descriptive I can be so you can understand how the character LCD works, making you able to interface it with any micro-controller available, and even driving it by hand.

If you are a careful reader you would notice, that the LCD in the circuit diagram is 16x2 instead 20x4 like in title. That"s because in eagle by default I couldn"t find one with 20x4. However, most of the displays will use HD44780 as LCD controller, so if you understand how to use a 16x2 or 20x4 display or any character display with this chipset, you should be able to cope with any sized character LCDs. Even the pins are the same for these displays.

After we have wired the LCD I"ll do my best to explain more or less how the LCD works. The addresses, initializations etc. I"ll be referring to this datasheet a lot, so keep it open when reading this article. Off-topic: One thing I want to teach beginners is to read datasheets, in my opinion very valuable skill to have. Even though the HD44780 datasheet is not the best ones I"ve read, I"ll try to fill in the gaps.

I will elaborate on the pins as we go on. The main thing is to understand briefly more or less what they are for. Even though when we will be reading the instruction sheet, you"ll see that the datasheet already provides which control pins you have to set HIGH and which LOW. So don"t worry about it so much.

As the names already suggest instruction register will be accessed for configuring and writing instructions to the LCD. DR register on the other hand will be used for writing the data you want for the display to show (not exactly accurate). You can see DR register as a buffer between two RAMs. It"s a temporary register which will eventually write itself automatically in of the available RAMs - CGRAM or DDRAM, depending on what you have written in IR.

DDRAM is used to temporary store the characters the display will show. So by changing the DDRAM, you will write text on your display. DDRAM stores the characters, how they will be drawn, depending on the code (page 10). You have the ability to put like 8 custom characters in CGRAM, but I won"t be elaborating on that. Actually, that would be a good homework. Try to read the datasheet and improve my code to support custom characters. It"s not that hard believe me.

Basically a busy flag is an indicator that the data from DR register is being written to one of the RAMs. You don"t want to change your data until it has finished writing it to the LCD. Otherwise the data will be corrupt and you end up showing Japanese characters (maybe). Basically the pin D7 is the busy flag, while it logic HIGH it means the data is being written to the LCD, when it"s 0 obviouslly it"s not busy anymore.

Address counter is basically a register, which specifies which block of RAM you want to either read or write to the LCD. It applies to both of the RAMs - DDRAM and CGRAM. While configuring the device, we will be able to set AC to be incremented or decremented automatically, so for most cases you won"t need to worry about it. Until we get to assigning coordinates where the text should be written.

But there is one important thing which I want to elaborate on, I even got confused on this matter. Basically the datasheet will tell you that there it has two modes 1-line display and 2-line display. From our perspective I have 4 line display, so how come there isn"t 4-line display available for DDRAM?

So far we have covered the main structure of the HD44780 LCD driver. You should now have an intuition of how the data is passed around and how it is stored. For CGRAM, you"ll have figure that on your own. Believe me it"s not that hard.

First thing we want to do is to initialize the display. Please see the Figure 24 on page 46 in datasheet. It has a nice diagram for the initialization.

It" s basically instruction to enable/disable the display, to show/hide the cursor and to make the cursor blink. Please refer to page 28 in datasheet.

As you can see it has 3 bits called D, C and B. Those are for configuring the things I mentioned before. But for initializition, we just turn off the display.

Final step you have to take to initialize the display. Basically in entry mode you configure whether the address counter (AC) will increment or decrement automatically and whether the display will shift instead of the cursor.

At this point we kind of have initialized the display, however we have to turn on the display. So after this, we have to call another Display on/off controlinstruction, this time we want to switch it on. And if you want for debugging or any other reason, you can enable now the cursor and the blinking of the cursor as well.

Remember, I was writing that you have to wait until the data is written in the RAM, either you substitute the lcdBusy() function for something like delay(1) or let"s write a function for checking the busy flag. See page 24 in datasheet, what command we have to send to read the busy flag, and which bit we will have to read.

So from the datasheet, we can see that we have to set RS to 0 and R/W to 1, and the BF is located on pin DB7. Taking all that into account, we can now write a function to wait until LCD has finished writing data to RAM. Another thing, because we are using 4 bits, we have to trigger the enable pin to read the upper 4 bits and then lower 4 bits. since we are only interested in BF for now, we can make a dummy trigger.

Basically those are all the necessary functions to communicate with the LCD. Now just to simplify our life, we can write a function to send string of characters automatically. I like to send a pointer to the string of characters and then just increment it until we reach the end. Just see my code you"ll understand.

Now you should be able to send text in a very user friendly manner. It probably would be a good idea to implement a way to move the cursor around the screen. See page 24 in datasheet, on how to set CGRAM address.

And that"s it! You have implemented all the basic functions to use a 20x4 HD44780 based character LCD display. I wrote a simple class like library for the arduino.

The LK204-7T is a 5.25” PC Bay Insert 1U with a 20x4 Intelligent LCD display designed to fit into 1U form factors. Engineered to quickly and easily add an elegant graphic HMI to any application. Multiple communication protocols such as Serial RS232, TTL, I2C, and USB communication models allow the LK204-7T Graphic LCD to be connected to a wide variety of host controllers.

Our Character LCD provides you with a cost-effective industrial HMI user interface solution for that great product/project you are developing. This LCD displays features optional on-board large and medium digits all with the convenience of a 7 key backlit tactile keypad will allow fast development for any application.20x4 1U Character LCD Display HMI

Liquid crystal displays (LCD) come in two main types that are of interest to hobby and DIY makers; Character LCD displays and pixel / graphic LCD displays. This intro “How To” will be covering the more popular and less expensive character LCD displays based on the very common Hitachi HD44780 controller.

LCD displays come in many sizes most often named by the number of rows and then the length of the display line. For example a 1x16 LCD display will have one row of sixteen characters and a 4x20 LCD display will have four rows with twenty characters in each.

LCDs can be have backlighting or be reflective (think calculator). In either case the programming that goes into working these displays is the same. LCDs with backlight normally use two pins to provide power to the backlighting.

2x16 character LCD with backlighting. Note, screen is all black, but to display characters the crystals move to allow the backlighting to show through.

Most LCDs that are being made now come with one row of sixteen pins. The first fourteen pins are used to control the display and the last two are for the backlighting (if the display has backlighting).

Older LCDs sometimes came with two rows of seven making a fourteen pin connector. These fourteen pins, most often, have the same signals on them that the 1x16 pin displays do. For example, pin #1 on the 2x7 connector is the same signal as pin #1 on the 1x16 connector, they are just arranged differently. If you have a 2x7 pin display but need to connect it to a 1x14 (1x16) backpack or device, the basic

LCDs based on the Hitachi HD44780 controller must be initialized after they are powered-up. The reason that the LCDs must be initialized is because there are a few critical options that the display must “know” before it can work or communicated properly.

The most import of which is wether to use an eight or four bit data interface. Hitachi and compatible LCDs can be set to use either 8 or 4 of the data pins to communicate with the host controller that is driving it. Using a four pin data bus lets you save on pins, but your controller must divide each instruction into two four bit segments and then send them one at a time to the display. So the trade off is less pins versus more programming and slower communication. (The reduced speed of having to send data twice has little effect on the display, but it does busy your processor for a longer amount of time.)

Ok, so you initialized your new 1x16 display and cleared it so that the cursor is at the first character position. Now you start sending your “Hello World” message to the screen.

When you send the LCD a character to display, you are not actually sending it to the screen part of the display, but rather a memory location that the display uses to know what to display on the screen. The problem here is that the memory location and the mapping to positions on the screen are not always sequential.

The “Hello World” example above is often what gives people trouble using a 1x16 LCD for the first time. Here the “r” “l” “d” went into memory address 0x88,0x89 and 0x8A which are not visible on this display !

Note that from the eight to the ninth character position the memory jumps. So, to finish displaying “Hello World” the controller would have to jump to memory location 0xC0 (at the red arrow) to continue displaying “rld”.

Solution: When you are ready to display a character in the ninth position on a 1x16 display you simply send the memory address to the display, but as a command.

For 1x16 and all the display larger then this, the memory mapping of the DDRAM (Display RAM) is not in the same range as the other commands, such as “clear display”, “home display” etc... so there is no problem sending the memory address as a command.

Here is a short list of popular display sizes and the memory mapping that we have found in them. Note: not all displays will necessarily have the same mapping, even when they are the same size. Use this a “Quick Start” reference when working on your own.

When it is actually time to use an LCD you have a few choices of how to do it. You can connect it directly to your Arduino or micro-controller (MCU) and use a lot of pins and wires or your could use a backpack.

Using a backpack has a few advantages over connecting the LCD directly to your micro-processor. Besides using less wires, (and pins) some backpacks take over the entire job of driving the display. All your code has to do is send the text out of the appropriate interface, I2C, serial, SPI etc ... This can save your micro-controller a lot of memory, and processor time. And, it also lets you get your projects working sooner, since you do not have to code and debug software to drive the display on top of the rest of your project.

A. Backpacks that do all the work, these free your MCU (and you) to do other tasks and when ready to display a message you simply send data to the backpack.

B. Backpacks that reduce the pin-out burden on your MCU. With this type of backpack, your MCU still initializes and drives the LCD, but through an interface with fewer wires.

Most displays work with the standard 128 ASCII characters. Often times, the displays are also able to display other characters, these include Asian characters and other special symbols and icons.

Your micro-controller measures a sensor and returns the value of five. You send the value to the display and you either get nothing or a strange looking character.

But, you can only send a single digit at a time to the display. So if you have the value of 139 to display, first it must be chopped into “1”, “3”, and “9” then you must add 48 to each before sending them to the display to convert the value into ASCII.