JarCastingUniversal Character/Graphics LCD Library for Java
Change Log
3.0.0 (04/30/2021)
- Modularized project (for jdk 11 above)
- Dropped input and character display modules
- Removed travis ci script.
2.0.0-alpha (07/04/2020)
- Added drawPixels() and drawPixelsBgra() method
- Added setPrimaryColor and setSecondaryColor methods in native class
- Added direct native access for BGRA buffers.
- Added GlcdInterfaceLookup utility class to provide additional information about a communication protocol
- New meta data information for fonts
- Renamed GlcdBufferType to GlcdBufferLayout
- Renamed GlcdBusInterface to GlcdCommProtocol
- Renamed GlcdBusType to GlcdCommType
- Renamed GlcdControllerType to GlcdController
- Apply alpha blending for primary and secondary colors in virtual mode
1.5.2-alpha (11/23/2019)
- Fixed missing dependencies in the aggregate jar
1.5.1-alpha (11/22/2019)
- Fixed 'symbol lookup error' (Issue: #22)
- Added support for multiple I/O peripheral providers (libgpiod, pigpiod, c-periphery) (Issue #24)
- 64 bit architectures are now fully supported for ARM and x86. Note that 32 bit support for OSX platform may be removed in the future versions.
- Added native logging capability for improved traceability (all native logging is routed to SLF4J)
- On Raspberry Pi platforms, GPIO pins are now automatically configured internally by the native library.
- API changes on GlcdConfigBuilder.
Features
General features
- Supports Graphics/Dot-Matrix display devices
- Support for multiple I/O peripheral providers
- Libgpiod
- Pigpio (Daemon or Standalone)
- C-Periphery (Based on the linux kernel)
- Provides native bindings (via JNI) to the U8g2 library for graphics displays.
- Provides a virtual driver interface allowing u8g2 native operations to be accessed in java. Useful for apps that needs to simulate u8g2 draw operations without the need for a real display device.
Display drivers
Graphic LCD driver features
- SPI and I2C hardware capability and other software bit-banging implementations
- Over 46+ controllers are supported. Refer to the table below for the list of supported display controllers.
- The graphics display module wraps around the popular c/c++ U8g2 library by Oliver. All drawing operations present in the library should be similar to the ones found in U8g2 (Refer to the official U8g2 reference manual for more information).
Supported display controllers
Graphic/Dot-Matrix LCD
- A2PRINTER, HX1230, IL3820, IST3020, KS0108, LC7981, LD7032, LS013B7DH03, LS027B7DH01, MAX7219, NT7534, PCD8544, PCF8812, RA8835, SBN1661, SED1330, SED1520, SH1106, SH1107, SH1108, SH1122, SSD1305, SSD1306, SSD1309, SSD1317, SSD1322, SSD1325, SSD1326, SSD1327, SSD1329, SSD1606, SSD1607, ST75256, ST7565, ST7567, ST7586S, ST7588, ST7920, T6963, UC1601, UC1604, UC1608, UC1610, UC1611, UC1638, UC1701
Supported bus interfaces (GLCD)
| Interface | Type | Description | Hardware | Software |
|---|---|---|---|---|
| SPI | 4-Wire | 4-Wire interface | YES | YES |
| SPI | 4-Wire (ST7920) | 4-Wire interface with no DC | YES | YES |
| SPI | 3-Wire | 3-Wire interface | NO | YES |
| I2C | Two-Wire | I2C Two-Wire interface | YES | YES |
| Parallel 8080 | Parallel | Parallel 8080 (Intel) | NO | YES |
| Parallel 6800 | Parallel | Parallel 6800 (Motorola) | NO | YES |
| Parallel 6800 | Parallel (KS0108) | Special KS0108 protocol. Mostly identical to 6800, but has more chip select lines | NO | YES |
| SED1520 | SED1520 | Special SED1520 protocol | NO | YES |
Project Resources
- Snapshot Builds - Builds from the latest development branch
- Release Builds - All release builds
Pre-requisites
- Java JDK 11+ (See AdoptOpenJDK)
- (Optional) Libgpiod (v1.4.1 or higher) - C library and tools for interacting with the linux GPIO character device (gpiod stands for GPIO device).
- (Optional) Pigpio (v71 above) - pigpio is a C library for the Raspberry which allows control of the General Purpose Input Outputs (GPIO).
IMPORTANT: For libgpiod, make sure the c++ bindings are included when you install from source (--enable-bindings-cxx)
Downloading Snapshots from Sonatype
To be able to download snapshots from Sonatype, add the following profile entry to your .m2/settings.xml file and activate with mvn -P sonatype install <....>.
<profile>
<id>sonatype</id>
<repositories>
<repository>
<id>ossrh</id>
<name>Sonatype OSS Maven Repository</name>
<url>https://oss.sonatype.org/content/groups/public</url>
<snapshots>
<enabled>true</enabled>
<updatePolicy>always</updatePolicy>
<checksumPolicy>fail</checksumPolicy>
</snapshots>
</repository>
</repositories>
</profile>
Installation
-
From maven repository - All in one package
<dependencies> <!-- Ucgdisplay Uber Jar --> <dependency> <groupId>com.ibasco.ucgdisplay</groupId> <artifactId>ucg-display</artifactId> <version>3.0.1</version> </dependency> </dependencies>
-
From maven repository - Specific module
<dependencies> <!-- Graphics display driver --> <dependency> <groupId>com.ibasco.ucgdisplay</groupId> <artifactId>ucgd-drivers-glcd</artifactId> <version>3.0.1</version> </dependency> </dependencies>
-
From source
Clone from Github (Sub-modules included)
git clone --recurse-submodules -j4 https://github.com/ribasco/ucgdisplay.git
Switch to the project directory
cd ucgdisplayInstall to your local maven repository
-
Installing from a Linux system with ARM 32/64 bit architecture
mvn install -Dcompile.native=true
-
Installing from a 64-bit
Linuxsystem forARMarchitecture 32 and 64 bit versionsmvn install -Dcompile.native=true -Dgraphics.target=native-build-cc-arm-all -Dinput.target=native-build-cc-arm-all -Dbuild.type=Debug
-
Installing from a 64-bit
Linuxsystem for all supported architecturesmvn install -Dcompile.native=true -Dgraphics.target=native-build-cc-all -Dinput.target=native-build-cc-all -Dbuild.type=Debug
Note: Please see the cross-compilation guide for more details
-
Usage examples
Simple hello world examples
Graphic LCD Example (ST7920 SPI Hardware)
Example forST7920 display controller using RPi's SPI Hardware capability (Other Examples).
Note: For I2C/SPI hardware capability, there is no need to map the pins explicitly.
import com.ibasco.ucgdisplay.drivers.glcd.*;
import com.ibasco.ucgdisplay.drivers.glcd.enums.*;
import com.ibasco.ucgdisplay.drivers.glcd.utils.XBMData;
import com.ibasco.ucgdisplay.drivers.glcd.utils.XBMUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.time.Duration;
import java.util.Objects;
/**
* ST7920 Example - Hardware SPI
*/
public class GlcdST7920HWExample {
private static final Logger log = LoggerFactory.getLogger(GlcdST7920HWExample.class);
public static void main(String[] args) throws Exception {
new GlcdST7920HWExample().run();
}
private void run() throws Exception {
//SPI HW 4-Wire config for ST7920
//NOTE: On Raspberry Pi, pins can be automatically configured for hardware capability (setting pin modes to ALT*).
//Automatic pin configuration for special modes will only take place if PIGPIO is installed
//Pinout for Main SPI Peripheral
// - MOSI = 10
// - SCLK = 11
// - CE1 = 7
GlcdConfig config = GlcdConfigBuilder
//Use ST7920 - 128 x 64 display, SPI 4-wire Hardware
.create(Glcd.ST7920.D_128x64, GlcdBusInterface.SPI_HW_4WIRE_ST7920)
//Set to 180 rotation
.option(GlcdOption.ROTATION, GlcdRotation.ROTATION_180)
//Using system/c-periphery provider
.option(GlcdOption.PROVIDER, Provider.SYSTEM)
//Set to 1,000,000 Hz/bps (1.00 MHz)
.option(GlcdOption.BUS_SPEED, 1000000)
//The SPI Bus (RPI as two SPI buses available, the Main and Auxillary)
.option(GlcdOption.SPI_BUS, SpiBus.MAIN)
//Use CE1 or Chip Select 1 on Main SPI peripheral/bus
.option(GlcdOption.SPI_CHANNEL, SpiChannel.CHANNEL_1)
.build();
GlcdDriver driver = new GlcdDriver(config);
//Clear the GLCD buffer
driver.clearBuffer();
//Write Operations to the GLCD buffer
driver.setFont(GlcdFont.FONT_6X12_MR);
driver.drawString(10, 10, "Hello World");
//Send all buffered data to the display
driver.sendBuffer();
//Clear the display
driver.clearDisplay();
}
}
Graphic LCD Example (ST7920 SPI Software)
Here is an alternative version of the above example using bit-bang method. (Other Examples)
Note: This is slower than SPI Hardware
import com.ibasco.ucgdisplay.drivers.glcd.*;
import com.ibasco.ucgdisplay.drivers.glcd.enums.*;
import com.ibasco.ucgdisplay.drivers.glcd.utils.XBMData;
import com.ibasco.ucgdisplay.drivers.glcd.utils.XBMUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.time.Duration;
import java.util.Objects;
/**
* ST7920 Example - SPI Software Bit-Bang.
*
* Note: This is ALOT slower than SPI HW
*/
public class GlcdST7920SWExample {
private static final Logger log = LoggerFactory.getLogger(GlcdST7920SWExample.class);
public static void main(String[] args) throws Exception {
new GlcdST7920SWExample().run();
}
private void run() throws Exception {
//SPI Software config for ST7920
//NOTE: For software/bit-bang implementation, pin modes will be automatically configured to OUTPUT by the native module
//Pinout for Main SPI Peripheral
// - MOSI = 10
// - SCLK = 11
// - CE1 = 7
GlcdConfig config = GlcdConfigBuilder
//Use ST7920 - 128 x 64 display, SPI Software implementation
.create(Glcd.ST7920.D_128x64, GlcdBusInterface.SPI_SW_4WIRE_ST7920)
//Set to 180 rotation
.option(GlcdOption.ROTATION, GlcdRotation.ROTATION_180)
//Using system/c-periphery provider
.option(GlcdOption.PROVIDER, Provider.SYSTEM)
//Map GlcdPin to BCM pin number
.mapPin(GlcdPin.SPI_MOSI, 10)
.mapPin(GlcdPin.SPI_CLOCK, 11)
.mapPin(GlcdPin.CS, 7)
.build();
GlcdDriver driver = new GlcdDriver(config);
//Clear the GLCD buffer
driver.clearBuffer();
//Write Operations to the GLCD buffer
driver.setFont(GlcdFont.FONT_6X12_MR);
driver.drawString(10, 10, "Hello World");
//Send all buffered data to the display
driver.sendBuffer();
}
}
Configuration options (All available options in GlcdOption enum)
| Option Name | Raw Type | Enum | Description | Category |
|---|---|---|---|---|
| PROVIDER | String | Provider | The default provider to use for communicating with the display. Available providers are libgpiod, pigpio, pigpiod and cperiphery. |
General |
| BUS_SPEED | Integer | N/A | The SPI/I2C bus speed in Hz | SPI/I2C |
| GPIO_CHIP | Integer | GpioChip | GPIO chip number. Will be translated to the actual GPIO device path. | GPIO |
| SPI_CHANNEL | Integer | SpiChannel | The SPI channel (Chip-Select). In raspberry pi, we have CE0 and CE1 for Main SPI and CE0, CE1, CE2 for Auxiliary. |
SPI |
| SPI_BUS | Integer | SpiBus | The primary bus to be used for SPI communication. In raspberry pi, there are two SPI peripherals available, the main and the auxillary. | SPI |
| SPI_MODE | Integer | SpiMode | SPI mode. Mode 0, 1, 2 or 3. Check source documentation for more info. (Default: 0) | SPI |
| SPI_BIT_ORDER | Integer | SpiBitOrder | SPI Bit Order. Can be either 0 = MSB First or 1 = LSB First. (Default: 0) |
SPI |
| SPI_BITS_PER_WORD | Integer | N/A | SPI Bits per word. (Default: 8) | SPI |
| SPI_FLAGS | Integer | N/A | Provider specific SPI flags. Only use this if you know what you are doing. Read more information on the provider's website (Default: 0). | SPI |
| I2C_DEVICE_ADDRESS | Integer | N/A | The address of the display device on the I2C bus. | I2C |
| I2C_BUS | Integer | I2CBus | The primary bus to be used for I2C communication. | I2C |
| I2C_FLAGS | Integer | N/A | Provider specific I2C flags. | I2C |
| ROTATION | Integer | GlcdRotation | The default rotation to set for the display. | General |
| PIGPIO_ADDRESS | String | N/A | The IP address of the pigpio daemon. (Default: 127.0.0.1) | General |
| PIGPIO_PORT | Integer | N/A | The port number of the pigpio daemon. (Default: 8888) | General |
| EXTRA_DEBUG_INFO | Boolean | N/A | Enable/Disable extra debug information to be displayed on the console (Default: false) | General |
Limitations
- Works only on linux kernel v4.8 or higher
- The adapters for character lcd driver
Mcp23008LcdAdapterandPcf8574TLcdAdapterare not yet implemented. - Due to lack of hardware availability, I am currently unable to test the
SPI,I2Cand bit-bang interfaces for most of the display controllers. The code implementation for these interfaces are complete, so In theory, they should work but it not confirmed. I am going to rely on your feedback for this and I will do my best to support any issues you may encounter.
Cross-Compilation Guide (for the Virtual driver interface)
Contributions are always welcome. For starters, checkout the guide to setting up your Dev/Build environment for more information.
Planned Features
- For the Character LCD library, I plan to move away from Pi4J (v1.2 still using Wiring Pi which is now deprecated) and use the native layer instead for device communication. This will allow us to use different peripheral providers of our choice.
Credits
- olikraus - Project maintainer of u8g2
- vsergeev - Project maintainer of c-periphery
- joan2937 - Project maintainer of pigpio
- brgl - Project maintainer of libgpiod