lcd module specification in stock

The 16x2 Alphanumeric LCD Display Module is equally popular among hobbyists and professionals for its affordable price and easy to use nature. As the name suggests the 16x2 Alphanumeric LCD can show 16 Columns and 2 Rows therefore a total of (16x2) 32 characters can be displayed. Each character can either be an alphabet or number or even a custom character. This particular LCD gas a green backlight, you can also get a Blue Backlight LCD to make your projects stand our and visually appealing, apart from the backlight color both the LCD have the same specifications hence they can share the same circuit and code. If your projects require more characters to be displayed you can check the 20x4 Graphical LCD which has 20 Columns and 4 Rows and hence can display up to 80 characters.

The 16x2 LCD pinout diagram is shown below. As you can see the module has (from right) two power pins Vss and Vcc to power the LCD. Typically Vss should be connected to ground and Vcc to 5V, but the LCD can also operate from voltage between 4.7V to 5.3V. Next, we have the control pins namely Contrast (VEE), Register Select (RS), Read/Write (R/W) and Enable (E). The Contrast pin is used to set the contrast (visibility) of the characters, normally it is connected to a 10k potentiometer so that the contrast can be adjusted. The Read/Write pin will be grounded in most cases because we will only be writing characters to the LCD and not read anything from it. The Register Select (RS) and Enable pin (E) pin are the control pins of the LCD and will be connected to the digital pins GPIO pins of the microcontroller. These pins are used to instruct the LCD where place a character when to clear it etc.

From DB0 to DB7 we have our eight Data Pins which are used to send information about the characters that have to be displayed on the LCD. The LCD can operate in two different modes, in the 4-bit Modeonly pins DB4 to DB7 will be used and the pins DB0 to DB3 will be left idle. In 8-bit Mode, all the eight-pin DB0 to DB7 will be used. Most commonly the 4-bit mode is preferred since it uses only 4 Data pins and thus reduces complexity and GPIO pin requirement on the microcontroller.Finally, we have the LED+ and LED- pins which are used to power the backlight LED inside our Display module. Normally the LED+ pin is connected to 5V power through a 100 ohm current limiting resistor and the LED- pin is connected to Ground.

16×2 LCD is named so because; it has 16 Columns and 2 Rows. There are a lot of combinations available like, 8×1, 8×2, 10×2, 16×1, etc. But the most used one is the 16*2 LCD, hence we are using it here.

All the above mentioned LCD display will have 16 Pins and the programming approach is also the same and hence the choice is left to you. Below is the Pinout and Pin Description of 16x2 LCD Module:

These black circles consist of an interface IC and its associated components to help us use this LCD with the MCU. Because our LCD is a 16*2 Dot matrix LCD and so it will have (16*2=32) 32 characters in total and each character will be made of 5*8 Pixel Dots.  A Single character with all its Pixels enabled is shown in the below picture.

So Now, we know that each character has (5*8=40) 40 Pixels and for 32 Characters we will have (32*40) 1280 Pixels. Further, the LCD should also be instructed about the Position of the Pixels.

It will be a hectic task to handle everything with the help of MCU, hence an Interface IC like HD44780 is used, which is mounted on LCD Module itself. The function of this IC is to get the Commands and Data from the MCU and process them to display meaningful information onto our LCD Screen.

The LCD can work in two different modes, namely the 4-bit mode and the 8-bit mode. In 4 bit mode we send the data nibble by nibble, first upper nibble and then lower nibble. For those of you who don’t know what a nibble is: a nibble is a group of four bits, so the lower four bits (D0-D3) of a byte form the lower nibble while the upper four bits (D4-D7) of a byte form the higher nibble. This enables us to send 8 bit data.

As said, the LCD itself consists of an Interface IC. The MCU can either read or write to this interface IC. Most of the times we will be just writing to the IC, since reading will make it more complex and such scenarios are very rare. Information like position of cursor, status completion interrupts etc. can be read if required, but it is out of the scope of this tutorial.

The Interface IC present in most of the LCD is HD44780U,in order to program our LCD we should learn the complete datasheet of the IC. The datasheet is given here.

There are some preset commands instructions in LCD, which we need to send to LCD through some microcontroller. Some important command instructions are given below:

As a 2inch IPS display module with a resolution of 240 * 320, it uses an SPI interface for communication. The LCD has an internal controller with basic functions, which can be used to draw points, lines, circles, and rectangles, and display English, Chinese as well as pictures.

The 2inch LCD uses the PH2.0 8PIN interface, which can be connected to the Raspberry Pi according to the above table: (Please connect according to the pin definition table. The color of the wiring in the picture is for reference only, and the actual color shall prevail.)

The LCD supports 12-bit, 16-bit, and 18-bit input color formats per pixel, namely RGB444, RGB565, and RGB666 three color formats, this demo uses RGB565 color format, which is also a commonly used RGB format.

For most LCD controllers, the communication mode of the controller can be configured, usually with an 8080 parallel interface, three-wire SPI, four-wire SPI, and other communication methods. This LCD uses a four-wire SPI communication interface, which can greatly save the GPIO port, and the communication speed will be faster.

2. The module_init() function is automatically called in the INIT () initializer on the LCD, but the module_exit() function needs to be called by itself

Python has an image library PIL official library link, it do not need to write code from the logical layer like C, can directly call to the image library for image processing. The following will take 1.54inch LCD as an example, we provide a brief description for the demo.

This module is an Arduino compatible LCD display module with high speed I²C interface. It can display 20×4 characters (white characters on a blue background).

NHD-12864AZ-FL-YBW | Monochrome Graphic Module | 128x64 Pixels | Transflective LCD | Yellow/Green Backlight | STN (+) Positive Yellow/Green Display | Non-Stocked

Newhaven 128x64 graphic Liquid Crystal Display module shows dark pixels on a bright yellow/green background. 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-12864AZ-FL-YBW display has an optimal view of 6:00, operates at 5V supply voltage and is RoHS compliant.

As digital displays get thinner and power-efficient performance becomes more critical, the Intel® Smart Display Module (Intel® SDM) specification and reference design delivers the same level of intelligence and interoperability as the Open Pluggable Specification (OPS) but in a smaller form factor targeted for integration into ultraslim all-in-one designs. No design housing means reduced cost. And the sleek design allows it to be fully integrated into visual IoT applications that require minimal space with maximum performance, such as hospitality screens and bedside terminals.