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Utility Classes

com.diozero.sbc

The com.diozero.sbc package contains classes for interfacing with Single Board Board Computers, most notably the DeviceFactoryHelper class which provides utility methods for accessing the automatically detected device factory for the local SBC on which your application is running. It also contains utility methods for graceful shutdown.

The other key class in this package is BoardPinInfo which provides various methods for accessing PinInfo instances, including by physical pin, GPIO character device chip and line offset, as well as GPIO number. The BoardPinInfo instance for your board should always be accessed via the device factory’s getBoardPinInfo() method.

For example, get by GPIO character device chip and line offset:

// GPIO 18 on the Raspberry Pi
int chip = 0;
int line_offset = 18;
PinInfo pin_info = DeviceFactoryHelper.getNativeDeviceFactory().getBoardPinInfo()
		.getByChipAndLineOffsetOrThrow(chip, line_offset);
try (LED led = new LED(pin_info, true, false)) {
	led.on();
	SleepUtil.sleepSeconds(1);
	led.off()
}

Get by physical pin:

// GPIO 18 on the Raspberry Pi
String header = "J8";
int physical_pin = 12;
PinInfo pin_info = DeviceFactoryHelper.getNativeDeviceFactory().getBoardPinInfo()
		.getByPhyscialPinOrThrow(header, physical_pin);
try (LED led = new LED(pin_info, true, false)) {
	led.on();
	SleepUtil.sleepSeconds(1);
	led.off()
}

com.diozero.util

The com.diozero.util package contain general utility classes, including:

BitManipulation
Interacting with individual bits within a byte.
ColourUtil
Currently contains one method for generating a colour value using the 5-6-5 colourspace from individual RGB values.
Crc
CRC-8 and CRC-16 calculator - supports all common configurations.
DiozeroScheduler
Wrapper around the Java ExecutorService and ScheduledExecutorService; provided to enable graceful shutdown on non-daemon threads.
Hex
Utility methods for encoding and decoding hex strings.
IOUtil
Input / output utility methods.
MmapIntBuffer
Wrap an system file into a memory mapped java.nio.IntBuffer object for high performance direct memory mapped control. Used for interacting with GPIO registers in /dev/gpiomem.
MutableByte
A mutable byte object with operations for getting / setting individual bit values.
PropertyUtil
Utility class for accessing system properties that are set either as environment variables or as -D command line flags.
RangeUtil
Map and contrain values between different ranges. Useful when converting percentage values in the range 0..1 to the 16-bit digital equivalent for ADCs and DACs.
ServoUtil
Utility methods for calculating servo pulse values.
SleepUtil
Wrap the Java Thread.sleep method with explicit options for sleeping for seconds or milliseconds. Also contains a busySleep method for finer grained delays.
StringUtil
Helper methods for padding a string and repeating a character.
TemperatureUtil
Convert from Celsius to Fahrenheit.
UsbInfo
Lookup USB vendor and product name from corresponding id values using /var/lib/usbutils/usb.ids.