i2c graphic lcd module quotation

The Serial Monitor is a convenient way to view data from an Arduino, but what if you want to make your project portable and view sensor values without access to a computer? Liquid crystal displays (LCDs) are excellent for displaying a string of words or sensor data.

This guide will help you in getting your 16×2 character LCD up and running, as well as other character LCDs (such as 16×4, 16×1, 20×4, etc.) that use Hitachi’s LCD controller chip, the HD44780.

As the name suggests, these LCDs are ideal for displaying only characters. A 16×2 character LCD, for example, can display 32 ASCII characters across two rows.

Character LCDs are available in a variety of sizes and colors, including 16×1, 16×4, 20×4, white text on a blue background, black text on a green background, and many more.

One advantage of using any of these displays in your project is that they are “swappable,” meaning that you can easily replace them with another LCD of a different size or color. Your code will need to be tweaked slightly, but the wiring will remain the same!

Before we get into the hookup and example code, let’s check out the pinout. A standard character LCD has 16 pins (except for an RGB LCD, which has 18 pins).

Vo (LCD Contrast) pin controls the contrast of the LCD. Using a simple voltage divider network and a potentiometer, we can make precise contrast adjustments.

RS (Register Select) pin is used to separate the commands (such as setting the cursor to a specific location, clearing the screen, etc.) from the data. The RS pin is set to LOW when sending commands to the LCD and HIGH when sending data.

R/W (Read/Write) pin allows you to read data from or write data to the LCD. Since the LCD is only used as an output device, this pin is typically held low. This forces the LCD into WRITE mode.

E (Enable) pin is used to enable the display. When this pin is set to LOW, the LCD ignores activity on the R/W, RS, and data bus lines; when it is set to HIGH, the LCD processes the incoming data.

The LCD has two separate power connections: one for the LCD (pins 1 and 2) and one for the LCD backlight (pins 15 and 16). Connect LCD pins 1 and 16 to GND and 2 and 15 to 5V.

Depending on the manufacturer, some LCDs include a current-limiting resistor for the backlight. It is located on the back of the LCD, close to pin 15. If your LCD does not contain this resistor or if you are unsure whether it does, you must add one between 5V and pin 15. It should be safe to use a 220 ohm resistor, although a value this high may make the backlight slightly dim. For better results, check the datasheet for the maximum backlight current and choose an appropriate resistor value.

Let’s connect a potentiometer to the display. This is necessary to fine-tune the contrast of the display for best visibility. Connect one side of the 10K potentiometer to 5V and the other to Ground, and connect the middle of the pot (wiper) to LCD pin 3.

That’s all. Now, turn on the Arduino. You will see the backlight light up. As you turn the potentiometer knob, you will see the first row of rectangles appear. If you have made it this far, Congratulations! Your LCD is functioning properly.

We know that data is sent to the LCD via eight data pins. However, HD44780-based LCDs are designed so that we can communicate with them using only four data pins (in 4-bit mode) rather than eight (in 8-bit mode). This helps us save 4 I/O pins!

The sketch begins by including the LiquidCrystal library. This library comes with the Arduino IDE and allows you to control Hitachi HD44780 driver-based LCD displays.

Next, an object of the LiquidCrystal class is created by passing as parameters the pin numbers to which the LCD’s RS, EN, and four data pins are connected.

In the setup, two functions are called. The first function is begin(). It is used to initialize the interface to the LCD screen and to specify the dimensions (columns and rows) of the display. If you’re using a 16×2 character LCD, you should pass 16 and 2; if you’re using a 20×4 LCD, you should pass 20 and 4.

In the loop, the print() function is used to print “Hello world!” to the LCD. Please remember to use quotation marks " " around the text. There is no need for quotation marks when printing numbers or variables.

The function setCursor() is then called to move the cursor to the second row. The cursor position specifies where you want the new text to appear on the LCD. It is assumed that the upper left corner is col=0 and row=0.

There are many useful functions you can use with LiquidCrystal Object. Some of them are listed below:lcd.home() function positions 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 the above function, use this inside a for loop for continuous scrolling.

lcd.display() function turns on the LCD display, after it’s been turned off with noDisplay(). This will restore the text (and cursor) that was on the display.

The CGROM stores the font that appears on a character LCD. When you instruct a character LCD to display the letter ‘A’, it needs to know which dots to turn on so that we see an ‘A’. This data is stored in the CGROM.

CGRAM is an additional memory for storing user-defined characters. This RAM is limited to 64 bytes. Therefore, for a 5×8 pixel LCD, only 8 user-defined characters can be stored in CGRAM, whereas for a 5×10 pixel LCD, only 4 can be stored.

After including the library and creating the LCD object, custom character arrays are defined. The array consists of 8 bytes, with each byte representing a row in a 5×8 matrix.

This smart little interface board makes so easy to interface to any Graphic 128x64 LCD. The display has 20 pins and controlling it via the parallel bus takes up a lot of pins. With this I2C interface board, only 4 wires is required. Control of backlight: Normal backlight use power 5V from +5V and can adjust with potentiometer. If you need control of backlight from microcontroller, pls cut-off connection of backlight on top side of board, and connect the Pin LED+ to any PWM out of microcontroller.

I2C_LCD is an easy-to-use display module, It can make display easier. Using it can reduce the difficulty of make, so that makers can focus on the core of the work.

We developed the Arduino library for I2C_LCD, user just need a few lines of the code can achieve complex graphics and text display features. It can replace the serial monitor of Arduino in some place, you can get running informations without a computer.

More than that, we also develop the dedicated picture data convert software (bitmap converter)now is available to support PC platform of windows, Linux, Mac OS. Through the bitmap convert software you can get your favorite picture displayed on I2C_LCD, without the need for complex programming.

I2C_LCD is an easy-to-use display module, It can make display easier. Using it can reduce the difficulty of make, so that makers can focus on the core of the work. We developed the Arduino library for I2C_LCD, user just need a few lines of the code can achieve complex graphics and text display features.

True to its name, these LCDs are ideal for displaying text/characters only. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows with 16 characters on each row.

If you plan to add a simple readable interface in your next project. alphanumeric LCD may be the most preferred one due to various factors such as low cost, easily programmable, having no limitation of displaying special & even custom characters.

But to use it directly with a microcontroller, you would need atleast 6 pins – RS, EN, D7, D6, D5, and D4 (with R/W pin permanently grounded for write operation). When you are engaged in a complex project bundled with large number of modules, you may face pin shortage for your microcontroller. In such situations, I2C LCD comes handy making use of only 2 pins (SDA & SCL) to talk to MCU, thereby saving atleast 4 pins. If you already have I2C devices, this LCD module actually uses no more pins at all.

Before moving further, lets see how an LCD can be controlled by I2C. In the image shown above, you can see a backpack module fitted to the back of the LCD. He does the work using an I/O expander PCF8574, that communicates with the micro-controller by I2C.

The PCF8574 provides general purpose remote I/O expansion for most microcontroller families via the two-line bidirectional bus (I2C-bus). The device consists of an 8-bit quasi-bidirectional port and an I2C-bus interface.

A quasi-bidirectional I/O can be used as an input or output without the use of a control signal for data direction. The PCF8574 has a low current consumption and includes latched outputs with high current drive capability. It also possesses an interrupt line (INT) which can be connected to the interrupt logic of the microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C-bus. This means that the PCF8574 can remain a simple slave device.

You can use this with LCD modules that have a HD44780-compatible interface with various screen sizes. The key is that your LCD must have the interface pads in a single row of sixteen, so it matches the pins on the backpack.

The three hardware address pins A0, A1 and A2 allow eight devices to be on the same I2C-bus. You can change the address of the device according to the status of each of these pins. The default address of the device is 0X3F (with PCF8574AT).

Note that backpack modules centered around PCF8574/PCF8574T (SO16 package of PCF8574 in DIP16 package) have a default slave address of 0×27. For those with PCF8574A/PCF8574AT chip, the default slave address will change to 0x3F.

Sample code for 16×2 LCD is given below. Upload the sketch to your Arduino board and you can see the LCD working. For 20×4 LCD, use the commented setup and comment the current setup.

WO128128A is a circular monochrome COG graphic LCD module made of 128x128 dot matrix format. This Circular LCD display module is built in with ST75161 IC; it supports 8080/6800 parallel, 3-wire and 4-wire serial SPI, I2C interface, Viewing Direction 6 o"clock, 1/136 driving duty, 1/12 BIAS.

The supply voltage for logic of WO128128A is 2.7V to 3.3V, typical value 3V. This circular LCD screen module can be operating at temperatures from -20℃ to +70℃; its storage temperatures range from -30℃ to +80℃. WO128128A is available in FSTN Negative (WO128128A-TDI) and FSTN positive LCD type with white LED backlight (WO128128A-TFH). The USB demo kits are available now; please contact us for USB sampling or quotation.

We are now producing circular displays with different technologies for a variety of applications and markets. Compared to traditional rectangular displays, many needs for beautiful round circular displays have been increasing in the market. They are a good fit for many applications such as home appliances, consumer products, industrial products, etc. The resolution of this circular LCD display is 128x128. This display communicates over 8080, 6800/4-line/ 3-line SPI or I2C interface.