Integrate GPIO functionalities

[RaiBnod]

GPIO functionalities will be written on C/C++. And we need able to call that functions from Java for doing GPIO operations.

Parent ticket: #42

[RaiBnod]

Hello @Aidan275, as you already did some code on C for doing GPIO operation. Can you please share the code.

I have created just a base class for generating the JNI libraries for doing communication with native C on commit: d72c520.

[RaiBnod]

Adding additional info:

BBBiO example: https://github.com/Aidan275/BBBiO
Parent ticket: https://github.com/NubeIO/NubeEdge28/issues/1

[RaiBnod]

@Aidan275 I had forked your C++ code and did small changes https://github.com/RaiBnod/BBBiO for testing. And for Java JNI call, I had made a Java micro-service base 478e478, where we can generate native library. With the help of the native build library and that Java native functional interface we can able to communicate with C.

But currently, it only supports digital read/write operations. And still we following todo tasks to complete on C:

• setPinMode - Configures the mode of a pin
• analogWrite - Write a PWM signal to an analog output pin
• analogRead - Read the voltage at an analog input pin
• attachInterrupt - Attaches an interrupt handler to detect changes on a digital input pin
• detatchInterrupt - Remove an interrupt handler

Could you please help me on this.

[cooperbrindle]

Additional Information

Prepare C/C++ code (SPI/PWM/GPIO of BBB) with APIs which can be called from Java (http://jonisalonen.com/2012/calling-c-from-java-is-easy)

Main functions needed at the moment are:

• setPinMode - Configures the mode of a pin
• digitalWrite - Write a HIGH or LOW to a digital output pin
• digitalRead - Read the status of a digital input pin
• analogWrite - Write a PWM signal to an analog output pin
• analogRead - Read the voltage at an analog input pin
• attachInterrupt - Attaches an interrupt handler to detect changes on a digital input pin
• detatchInterrupt - Remove an interrupt handler

Resources:

• GPIO via mmap Exercise
• AM335x Technical Reference Manual
• BeagleBone Black GPIO Benchmark

[zero88]

Java need to provide interface and build a header file then C++ implementation should be in
https://github.com/NubeIO/BBBiO

[zero88]

#70