In Part 1
of his series on using Java ME 8 to control Internet of Things (IOT) devices--such as LEDs, relays, LCDs, sensors, motors, and switches--connected to a Raspberry Pi, Jose Cruz explained how to work with devices that use a simple general-purpose input/output (GPIO) interface. GPIO devices can be used as either a digital input or digital output, can be disabled or enabled, and can be used to drive interrupt lines. Part 1 explored how to connect and control a flame sensor, a movement sensor, and a motion sensor.
In Part 2
of his series, Cruz described how to connect and control devices that use an inter-integrated circuit bus (I2C) interface.
Now, in Part 3
of the series, Cruz demonstrates how to use universal asynchronous receiver/transmitter (UART) interfaces to connect devices that read latitude, longitude, altitude, and time from a GPS receiver engine board and provide the information via spoken voice in English and Spanish.
As before, you will see how to develop Java ME 8 classes that allow you to gather data and control these devices. The code for the classes is very similar, so once you understand it, you will be able to create new classes that control additional UART devices to create your own IoT world.