lcd module hd44780 controller free sample

ERM1602FS-3 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,fstn-lcd positive,black text on the white color,high contrast,wide operating temperature range,wide view angle,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.

ERM1601SYG-2 is 16 characters wide,1 row 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.

The HD44780 is a controller for display developed by Hitachi commonly used to manage alphanumeric dot matrix LCD. This controller is a standard de-facto for this kind of display. It is often used in industrial test equipment, networking equipment, vending machine and in embedded projects.

Compatible LCD screens are manufactured in several standard configurations. Common sizes are one row of eight characters (1×8), as well as 16×2, 20×2 and 20×4 formats. Larger custom sizes are made with 32, 40 and 80 characters and with 1, 2, 4 or 8 lines. The most commonly manufactured larger configuration is 40×4 characters, which requires two individually addressable HD44780 controllers with expansion chips as a single HD44780 chip can only address up to 80 characters. A common smaller size is 16×2, and this size is readily available as surplus stock for makers and prototyping work.

We want to provide a full library for HD44780 compatible with ChibiOS/HAL 3.0 ad a demo explaining gradually how software has been designed. This task requires a preliminary read of HD44780 datasheet.

In this article we are going to use a 16×2 LCD driven by HD44780. This display usually comes with a monochromatic backlight and a 16 PIN header connector.

In our case we have connected the LCD to an STM32 Nucleo-64. The first two PINs are required to power up the chip. Our connections are VSS to GND and VDD to 5V. The contrast regulator PIN (V0) has been connected to a 20k potentiometer which is between 3.3V and GND.

All the information about HD44780 working principle are extracted by the documentation previously introduce. We are going to summarise them in order to achieve our goal which is design a flexible library.

This controller has two 8-bit register: the instruction register (IR) and the data register (DR). The IR stores instructions. The DR temporarily stores data to be written into RAM.

When communicating with the HD44780 we can pull up RS to select the DR or pull down RS to select IR. This explains somehow this snippet of code we can find in the library:

The HD44780 has actually two RAM having two different purposes and one ROM: Data Display RAM (DDRAM), Character Generator RAM (CGRAM) and Character Generator ROM (CGROM).

The CGROMcontains a preset of characters which associate an 8-bit word to a pattern which actually is a bit matrix 5×8 or 5×10 representing the configuration of pixel required to draw that character on the LCD. The CGRAM could be used to edit these preset at run time.

For our purpose we are much more interested in DDRAM:HD44780 has typically a DDRAM which is enough big to address an 80 character display. Each DDRAM address indicate a block of memory required to represent a full character. In this way we have a correspondence one to one between DDRAM addresses and display “cells”.

To configure the HD44780 we need to read and write words which length is 8-bit. Each word could be an instruction as well as a data which must be stored in CGRAM or DDRAM. Sending instruction we can configure the device, writing data in DDRAM we can write on the display.

Note that lcdp is a structure representing the LCDDriver which contains among other fields the PIN-map of our display which is obviously required by this function.

In case of write, the HD44780 sample the status of data PIN when E shift from high to low so we can also set the logical status of Ds before to set E as high.

This function is compatible also with 4-bit mode. The HD44780 could be addressed using only 4 data PINs (D4 to D7). In this case two transfers are required to send a whole word as shown in figure 4.

Clear display: clear the DDRAM and set the current address of DDRAM to 0. It set also the display position and the cursor position to 0. This command is exported through the APIlcdClearDisplay().

Return home: perform the same operation of Clear Display without clear the DDRAM content so the text on the display will be untouched after this command. This command is exported through the APIlcdReturnHome().

Cursor/Display shift: allow to shift of one position the Display (S/C = 1) or the Cursor (S/C = 0). In our library this instruction is partially exposed through the API lcdDoDisplayShift().

Function set: it allow to set the interface mode in 8-bit mode (DL = 1) or 4-bit mode (DL = 0), the number of lines to 2 (N = 1) or 1 (N = 0) and the font type size to 5 × 10 dots (F = 1) or 5 × 8 dots (F = 0). Note that this instruction must be sent in the initialization phase which strictly depends on DL. In our library data length is selectable by a preprocessor switch named LCD_USE_4_BIT_MODE, number of lines and font type is selectable in the display configuration structure.

Set DDRAM address: allow to set the DDRAM address. In our library this instruction is exposed through the API lcdSetAddress() and internally used by the API lcdWriteString().

On start up an internal circuit perform an initialisation which lead the HD44780 in a know status. If the device is not powered properly or if it has been misconfigured it could happen that this initialization doesn’t occurs. In that case there is a procedure of initialization by instruction which is different if we want to use 8-bit or 4-bit mode. Note that if we would change the operation mode a re-initialization is required.

Note that the latest five instructions are still part of the initialization but depends strictly on user configuration which is stored in the LCDDriver structure and lcdp is a pointer to it.

The LCDDriver contains the current state, the current backlight percentage and a pointer to the current configuration. This configuration is defined by user and used in lcdStart().

The configuration allow to enable/disable cursor and blinking, to choose font type and the number of lines. It contains also the PIN-map of the LCD and backlight related fields.

Note that the PIN-map of the LCD depends on the used interface. It is basically a structure and one of its field is an array of lines which length depends on LCD_USE_4_BIT_MODE:this array indeed represent the D pins which are 4 instead of 8 in 4-bit mode.

It is also important to note that configuration structure has three additional fields when LCD_USE_DIMMABLE_BACKLIGHTisenabled. These fields are a PWM driver , its configuration and the channel which is connected to the LCD backlight. When this option is disabled the backlight percentage is considered a boolean (e.g. the display back light is on when this value is not zero).

This function must be invoked before to use any of all the exposed functions, it requires void and return void. Note that it act on objects and there is no initialization of hardware on this function. After the execution of it the driver goes in the LCD_STOP state.

This function configure the hardware to be ready to use. It requires the pointer to the driver and a pointer to the configuration which is user defined. After the execution of it the driver goes in the LCD_ACTIVE state.

This function reset the hardware stopping it. It requires the pointer to the driver only. After the execution of it the driver goes int the LCD_STOP state.

It set backlight percentage to 100. It doesn’t requires LCD_USE_DIMMABLE_BACKLIGHT. It requires the pointer to the driver only and after the execution of it the driver remains in the LCD_ACTIVE state.

It set backlight percentage to 0. It doesn’t requires LCD_USE_DIMMABLE_BACKLIGHT. It requires the pointer to the driver only and after the execution of it the driver remains in the LCD_ACTIVE state.

This function execute the Clear Display: clear the DDRAM and set the current address of DDRAM to 0. It set also the display position and the cursor position to 0. It requires the pointer to the driver only and after the execution of it the driver remains in the LCD_ACTIVE state.

This function execute theReturn home: perform the same operation of Clear Display without clear the DDRAM content so the text on the display will be untouched after this command. It requires the pointer to the driver only and after the execution of it the driver remains in the LCD_ACTIVE state.

This function execute theSet DDRAM address. It requires the pointer to the driver and the DDRAM address. After the execution of it the driver remains in the LCD_ACTIVE state.

This function set the DDRAM address and pushes a string in it. Requires the pointer to the driver, the string and the starting DDRAM address. After the execution of it the driver remains in the LCD_ACTIVE state.

This function perform a Shift of the display. Requires the pointer to the driver, and the direction of the shift which could be LCD_RIGHT or LCD_LEFT. After the execution of it the driver remains in the LCD_ACTIVE state.

This function set the LCD percentage to a value in a range from 0 an 100. Requires the pointer to the driver, and the percentage value. After the execution of it the driver remains in the LCD_ACTIVE state. This API is available only if LCD_USE_DIMMABLE_BACKLIGHT.

This function gradually shift the backlight percentage to 0 creating a smooth effect. Requires the pointer to the driver only. After the execution of it the driver remains in the LCD_ACTIVE state. This API is available only if LCD_USE_DIMMABLE_BACKLIGHT.

This function gradually shift the backlight percentage to 100 creating a smooth effect. Requires the pointer to the driver only. After the execution of it the driver remains in the LCD_ACTIVE state. This API is available only if LCD_USE_DIMMABLE_BACKLIGHT.

The display thread, which actually is the main, starts the LCD with the user defined configuration, writes a string for each line of the display and continuously perform shift creating a simple animation on the display.

Liquid Crystal Display(LCDs) provide a cost effective way to put a text output unit for a microcontroller. As we have seen in the previous tutorial, LEDs or 7 Segments do no have the flexibility to display informative messages.

This display has 2 lines and can display 16 characters on each line. Nonetheless, when it is interfaced with the micrcontroller, we can scroll the messages with software to display information which is more than 16 characters in length.

The LCD is a simple device to use but the internal details are complex. Most of the 16x2 LCDs use a Hitachi HD44780 or a compatible controller. Yes, a micrcontroller is present inside a Liquid crystal display as shown in figure 2.

Power & contrast:Apart from that the LCD should be powered with 5V between PIN 2(VCC) and PIN 1(gnd). PIN 3 is the contrast pin and is output of center terminal of potentiometer(voltage divider) which varies voltage between 0 to 5v to vary the contrast.

The Hitachi HD44780 LCD controller is an alphanumeric dot matrix liquid crystal display (LCD) controller developed by Hitachi in the 1980s. The character set of the controller includes ASCII characters, Japanese Kana characters, and some symbols in two 28 character lines. Using an extension driver, the device can display up to 80 characters.

The Hitachi HD44780 LCD controller is limited to monochrome text displays and is often used in copiers, fax machines, laser printers, industrial test equipment, and networking equipment, such as routers and storage devices.

Compatible LCD screens are manufactured in several standard configurations. Common sizes are one row of eight characters (8×1), and 16×2, 20×2 and 20×4 formats. Larger custom sizes are made with 32, 40 and 80 characters and with 1, 2, 4 or 8 lines. The most commonly manufactured larger configuration is 40×4 characters, which requires two individually addressable HD44780 controllers with expansion chips as a single HD44780 chip can only address up to 80 characters.

Character LCDs use a 16 contact interface, commonly using pins or card edge connections on 0.1 inch (2.54 mm) centers. Those without backlights may have only 14 pins, omitting the two pins powering the light. This interface was designed to be easily hooked up to the Intel MCS-51 XRAM interface, using only two address pins, which allowed displaying text on LCD using simple MOVX commands, offering cost effective option for adding text display to devices.

R/W : Read/Write. 0 = Write to display module, 1 = Read from display module (in most applications reading from the HD44780 makes no sense. In that case this pin can be permanently connected to ground and no processor pins need to be allocated to control it.)

In 8-bit mode all transfers happen in one cycle of the enable pin with all 8 bits on the data bus and the RS and RW pins stable. In 4-bit mode, data are transferred as pairs of 4-bit "nibbles" on the upper data pins, D7-D4 with two enable pulses and the RS and RW pins stable. The four most significant bits (7–4) must be written first, followed by the four least significant bits (3–0). The high/low sequence must be completed each time or the controller will not properly receive further commands.

Selecting 4-bit or 8-bit mode requires careful selection of commands. There are two primary considerations. First, with D3-D0 unconnected, these lines will always appear low (0b0000) to the HD44780. Second, the LCD may initially be in one of three states:

The same command is sent three times, Function Set with 8 bit interface D7-D4 = 0b0011, the lower four bits are don"t care, using single Enable pulses. If the controller is in 4 bit mode the lower four bits are ignored so they can"t be sent until the interface is in a known size configuration.

In all three starting cases the bus interface is now in 8 bit mode, 1 line, 5×8 characters. If a different configuration 8 bit mode is desired an 8 bit bus Function Set command should be sent to set the full parameters. If 4 bit mode is desired 0b0010 should be sent on D7-D4 with a single enable pulse. Now the controller will be in 4 bit mode and a full 4 bit bus Function Set command sequence (two enables with command bits 7-4 and 3–0 on subsequent cycles) will complete the configuration of the Function Set register.

The original HD44780 character generator ROM contains 208 characters in a 5×8 dot matrix, and 32 characters in a 5×10 dot matrix. More recent compatible chips are available with higher resolution, matched to displays with more pixels.

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.

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.

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.

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!

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.

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.