glcd - Graphic LCD Library
by Andy Gock
Up to date documentation
For up to date documentation, please see the doxygen pages under the
doxygen_pages directory and within the source code.
A online version can also be seen at:
However this site may not always be kept up to date.
Welcome to GLCD, an open source graphic LCD library written by Andy Gock.
Author's web site: https://agock.com/
GitHub repository: https://github.com/andygock/glcd
This library has been written cleanly, to allow easy modification for use with different microcontroller devices and controller chipsets. Logic relating to devices and controllers are palced in seperate files and specific implementations can be chosen by the use of special defined symbols.
It is suitable for monochrome (black and white) LCDs with page by page data and command write style data transfer protocol. It is not compatible with color graphic LCDs.
- Draw text, of different sizes, from small 5x7 pixel fonts to large custom characters. Custom fonts can be generated using free MikroElektronika Font Creator software.
- Can write text from SRAM and Flash memory.
- Scrolling text.
- Draw vertical or horizontal bar graphs, with or without borders.
- Draw circles, lines, rectangles - filled or unfilled.
- Draw individual pixels in any color (black or white).
- Display is fully buffered, for a Nokia 5110 display of 84x48 dots, you'll need at least 504 bytes of SRAM to store the frame buffer.
- It only writes the part of the frame buffer which has changed. It does not re-write the entire buffer to the LCD every frame update.
Controllers and chipsets
- PCD8544 based LCDs, e.g Nokia 3110 and 5110 LCDs
- ST7565R / ST7565P serial interface
- NT75451 parallel interface (used on NGX BlueBoards)
The following graphic displays have been physically tested with and confirmed working:
- Atmel AVR 8-bit
- NXP LPC111x ARM Cortex-M0
- NXP LPC11Uxx ARM Cortex-M0
- ST STM32 F0 ARM Cortex-M0
- ST STM32 F4 ARM Cortex-M4
- Microchip PIC24H (and probably other 16-bit MCUs)
Development boards tested on (with on-board LCD)
- NGX BlueBoard LPC11U37 (with on-board NT75451 graphic LCD)
Development boards tested on (without on-board LCD)
- Microstick II with PIC24H and Nokia 3310/5110 LCD, ST7565R and ST7565P
- ST Nucleo F401RE
Not all combinations of microcontroller platform and LCD controllers are supported out of the box. However you can edit the files
controllers/ and add your desired combination. More information on how to do this can be read in the doxygen documentation.
Setup of symbols for compiler
The following symbols need to be defined for the compiler:
Pick microcontroller type (pick one only):
GLCD_DEVICE_LPX111X GLCD_DEVICE_LPX11UXX GLCD_DEVICE_AVR8 GLCD_DEVICE_STM32F0XX GLCD_DEVICE_STM32F4XX GLCD_DEVICE_PIC24H
Select LCD controller
Pick LCD controller type (pick one only):
GLCD_CONTROLLER_PCD8544 GLCD_CONTROLLER_ST7565R GLCD_CONTROLLER_NT75451
For ST7565P controllers, treat as ST7565R. For most if not all parts here, they behave the same way.
Select SPI or parallel interface
If using a parallel interface LCD (e.g NT75451 on NGX BlueBoard):
When using SPI controllers:
Note the SPI symbol isn't actually checked by the source at the moment, and it is fine if it is not used. It is for forward compatibility only. One day I may decide to check for it.
For the Newhaven displays using ST7565 based controllers listed above which have been tested as working, there are certain initialisation sequences which should be followed, and this may vary from display to display. To force a certain (and tested) initialisation sequence, define one of the following:
GLCD_INIT_NHD_C12832A1Z_FSW_FBW_3V3 GLCD_INIT_NHD_C12864A1Z_FSW_FBW_HTT GLCD_INIT_NHD_C12864WC_FSW_FBW_3V3_M GLCD_INIT_ZOLEN_12864_FFSSWE_NAA
If you don't specify a NHD model, ST7565 controller selection will default to
GLCD_INIT_NHD_C12864WC_FSW_FBW_3V3_M sequence. This however may change in the future.
To set a reset time, used by the
glcd_reset() function, set
GLCD_RESET_TIME to desired duration in milliseconds.
When using PCD8544 controllers, define a
PCD8544_CONTRAST symbol with a 8-bit unsigned integer for the contast value. If this is not defined, a default value will be used.
GLCD_LCD_HEIGHT to define custom LCD dimensions. If these are not user defined, then a default width and height is used. The default dimensions are 128x64 except for PCD8544 controllers which is 84x48.
These symbols need to be set in the configuration options of your IDE, usually in the "defined symbols" section, or they can be defined in a makefile as
Some operations such as sending a reset pulse, requires the use of a delay timer. The library will refer to a external function called
delay_ms(t) where t is the delay required in milliseconds. Please ensure you have this function elsewhere in your program.
If you are using avr-gcc with Atmel devices, you can force the library to use the built-in
_delay_ms() function by setting the compiler symbols:
F_CPU must be set to your clock frequency for the above AVR built-in delay routine to work.
- STM32F0 Discovery with PCD8544 Nokia 5110 LCD - Download Keil MDK project
- Custom PCB with Atmel ATMEGA2560 and ST7565R Newhaven 128×64 display - Download Atmel Studio 6 project
- Atmel AT90USBKEY board with PCD8544 Nokia 5110 LCD - Download Atmel Studio 5 project
- ZERO Z111xP Cortex-M0 LPC1114 board with PCD8544 Nokia 5110 LCD - Download CooCox CoIDE project or watch video
- NGX LPC11U37 BlueBoard with built in NT75451 parallel chipset LCD - Download Keil MDK project
- Microstick II development board, with PIC24H and Newhaven ST7565R display NHD-C12864A1Z-FSW-FBW-HTT - Download MPLAB X project or watch video
- Microstick II development board, with PIC24H and Newhaven ST7565P display NHD-C12832A1Z-FSW-FBW-3V3 - Download MPLAB X project or watch video
- Microstick II development board, with PIC24H and PCD8544 Nokia 5110 display - Download MPLAB X project
- Pinguino development board, with PIC32MX440F256H and PCD8544 Nokia 5110 display - Download MPLAB X project (Thanks to Joris Putcuyps)
The code samples above will have the glcd library code already inside it, however I haven’t made any attempt to keep the glcd library updated in the examples so I advise that if you are using the example code, to replace the glcd directory (usually in
lib/glcd) with the latest updated code.
Display bitmap images
Bitmap images can be converted into a byte array using LCD Assistant
When using this software, we need to set 8 pixels per byte with vertical byte orientation. Do not include size.
Refer to Doxygen generated pages for detailed documentation. You'll can generate the documentation yourself, simply install Doxygen and load the doxygen file in the root directory of the library and generate the documents in a file format of your choice (HTML, PDF, TEX etc).
There is also an online version.