LinuxFS Provider

The current implementation of the LinuxFS plugin implements a file based I2C and PWM provider. The file based I2C provider opens /dev/i2c-1 using a RandomAccessFile to perform I2C reads and writes. The file based PWM provider opens /sys/class/pwm/pwmchip? using a RandomAccessFile to perform PWM operations.

The Linuxfs provider linuxfs-pwm requires minimum kernel Bullseye 6.1.21 and Bookworm 6.6.22 !

Providers in the LinuxFS plugin:

  • linuxfs-i2c
  • linuxfs-pwm
  • Under construction
    • linuxfs-digital-input
    • linuxfs-digital-output

To use the LinuxFS provider include the following dependencies:


And then one can get access to the I2C provider as follows:

Context pi4j = Pi4J.newAutoContext();
I2CProvider i2CProvider = pi4j.provider("linuxfs-i2c");
I2CConfig i2cConfig = I2C.newConfigBuilder(pi4j).id("TCA9534").bus(1).device(0x3f).build();

try (I2C tca9534Dev = i2CProvider.create(i2cConfig)) {

	int config = tca9534Dev.readRegister(TCA9534_REG_ADDR_CFG);

	tca9534Dev.writeRegister(TCA9534_REG_ADDR_OUT_PORT, currentState);
	tca9534Dev.writeRegister(TCA9534_REG_ADDR_CFG, (byte) 0x00);

	tca9534Dev.writeRegister(TCA9534_REG_ADDR_OUT_PORT, newState);


And then one can get access to the PWM provider as follows:

     * Builds a new PWM configuration for the buzzer
     * @param pi4j    Pi4J context
     * @param address BCM pin address
     * @return PWM configuration
    protected static PwmConfig buildPwmConfig(Context pi4j, int address) {
        return Pwm.newConfigBuilder(pi4j)
            .id("BCM" + address)