32x4 lcd display free sample

In this tutorial I am going to explain about the pin out, working and control systems of character lcd’s. Character lcd’s comes in many sizes for example 8×1, 8×2, 8×4, 16×1, 16×2, 20×1, 20×2, 20×4, 24×1, 24×2, 24×4, 32×1, 32×2, 40×1, 40×2 and 40×4. In these MxN dimensions, M represents number of coulombs & N represents number of rows.

All these Lcd’s available in market have 14 or 16 pins depending on the vendor/supplier. Also they all contains a same lcd controller in them which controls all their activities. Talks to external peripherals(like microcontrollers) receives data from external devices and displays them on lcd display screen. Generally every character lcd has HD44780 controller in it which controls every operation of character lcd. Some variants and competitors of HD44780 also placed step in embedded market but they are not popular for exampleAIP31066 , KS0066 , SPLC780 and ST7066 lcd controller.

In these 14 pins, 8 are data pins(FromDB-0toDB-7). Three are lcd control pinsRS(Register Select),R/W(Read-Write) &En(Enable). Two are lcd power pinsVcc(+5v)Vss(Gnd). The last pin islcd contrast pin(V0).

If lcd contains 16 pins than the extra 2 pins are LED+ and LED- pins. LED+ and LED- are for lcd’s back light, if you want to switch on the back light of lcd then use these pins other wise leave them void.

Character lcd’s which have pins arranged in two lines like headers, their pin-out is given below. Female header pin-out is shown below. Vendors for ease pre-solder the lcd pins and provide a female header for connections.

Mostly character lcds contains HD44780U lcd controller in them. HD44780 was developed by Hitachi. A single HD44780 can handle up to 80 characters. In 40×4 lcd display total characters which we can display on lcd are 40×4=160. So to control 160 characters we need two HD44780 controllers. To work with two HD44780 controllers we need an extra pin to energize the second controller.

Lcd contrast pin is same like fine tuning your television. In televisions we fine tune stations using remote but in character lcd’s we have to manually do it by varying the resistance. Varying the resistance means we control the input current to lcd. Varying resistance will fade or brighten the characters or data appearing on lcd screen.

Character Lcd’s can be interfaced in 8-bit and 4-bit mode with external controllers. In 8-bit mode all the data lines(DB0-DB7) of lcd are utilized. In 4-bit mode only four data pins of lcd are utilized (DB7-DB4). In 4-bit mode first the 8-bit ASCII value is divided in to two nibbles, first the upper nibble is send on data line and then the lower nibble. 4-bit mode is used when we want to save GPIO pins of our external device like microcontoller. An example of lcd connection with remote controller is shown in the picture below.

I prepared a good tutorial on interfacing character lcd in 8-bit and 4-bit mode with microcontrollers. Demo codes are also presented and explained in the post. Click the below button to take the tutorial.

Holtek’s HT162x series of devices are a range of ram mapping LCD drivers which support multiple LCD display modes. These devices include serial communication, a WDT and Time Base functions. A tone function provides a fixed frequency output which can be used to drive a piezo buzzer. The integrated power saving mode greatly reduces power consumption. The HT1621 is a 128-pattern (32x4) LCD driver chip in the series. HT1621B is the part number for its 48SSOP and 48LQFP package.

Download our Crystalfontz LCD Software. We provide software for you to test many types of LCDs including character displays and graphic displays. Our character and graphic USB display modules can use CrystalControl2 to quickly set up the display. Bitmap to ePaper and Image2Code provide a simple interface to add an image to your display. We also USB LCD drivers and demonstration code for Linux.

An import function allows additionally to use Windows fonts. With the FontEditor it is easy to generate for example Cyrillic, Greek and Arabic fonts. The preview function shows immediately the size and style in simulation window. When the testboard EA 9780-2USB is connected to the USB port, you can see the character (or any predefined text) live on the display which is plugged-in!