bj. Graphics LCD with touchscreen

GLCD also provides negative voltage generator to drive LCD. Only a small trimmer is needed to set the display contrast. The display illumination can be switched on or off via a small MOS-FET transistor that is connected to RA4 pin of PIC18F4550.

The GLCD features an optional touchscreen that can easily be easily mounted by sticky stripes that attach it to the frame of the GLCD. The touchscreen is connected to PIC18F4550 microcontroller through 4 pins that function as analog inputs and digital outputs. Reading position and pressure from the touchscreen is described in How to connect a 4-wire resistance touchscreen to a PIC microcontroller? article.

GLCD needs a high speed data channel to the microcontroller. LGM12864B GLCD has an 8-bit data bus and 6 control signals. A PIC18F4550 microcontroller wih GLCD is connected to a PC via USB 2.0, or to another microcontroller via I²C bus. I²C Slave functionality is described here.

Graphics LCD (GLCD) is a special kind of LCD that enables drawing text and graphics. It usually has no character generator, so all the ASCII characters has to be displayed in graphics. However, very different text sizes are possible. The character patterns have to be stored in a microcontroller that operates the GLCD.

NOTE: Program PIC18F4550 firmware v2.7.2 (for GLCD) to your PIC18F4550 to use the sample applications. The new firmware provides fast communication to GLCD and ASCII character patterns. The new firmware also supports reconfiguration with PC USB Projects HEX Editor v3.0 and a special PIC18F4550.FWI file.

The first GLCD example application (PIC18F4550 - GLCD example.zip) is still available from Downloads section. The application shows all the basic principles of a microcontrolers to GLCD communication and also provides touch screen position (X,Y) and touch pressure reading. This application also enables one to test operation of hardware connections to the display since each pin may be tested individually.

GLCD HARDWARE TESTING APPLICATION:

The example is based on the new LIB_PCUSBProjects v6.0.NET4(x64).dll. LIB_PCUSBProjects v6.0.NET4 header file is available from Downloads section. The new example supports advanced display and touchscreen control functions that provide fast access from PC to the display via USB 2.0.

- INVERTED WIDE (3)

GLCD DEMO v3 programming example with source code (GLCD DEMO v3 (x64).zip) has been added. Four text styles are now supoorted:

- NORMAL (0)

- INVERTED NORMAL (1)

- WIDE (2)

GLCD DEMO v3 APPLICATION WITH SOURCE CODE:

GLCD DEMO with source code. Click on the screenshot to enlarge it.

GLCD with touchscreen connection to PIC18F4550 microcontroller.

Click on the picture to enlarge it.

NOTE 2: GLCD may be connected to an I²C master device via SDA, SCL and GND lines. Pull-up resistors must be provided by the master device. See Modular Weather Station Project for more information on implementing an I²C master device.

Inside the GLCD. Click on the photo to enlarge it.

ALSO READ:

- PROGRAMMING GUIDE

- How to connect a 4-wire resistance touchscreen to a PIC microcontroller?

- How to display text on a graphics display?

- Modular Weather Station Project

- PIC18F4550 firmware v2.7.2 (for GLCD) I²C slave functionality