Interfacing PIC Microcontroller with Java on PC using USB

Question

HI! I want to interface PIC18F4550 with Java program and make it cross-platform initially. There are only one way I now Java has is javacomm. But i want it to be USB because not every laptop has RS232 port nowadays. Waht are the ways of interfacing PIC with Java you can suggest to make it really cross-platform and avoid writing driver for every new OS?

Answer 1

Arduino's approach should be adaptable to your needs: a microcontroller with hardware UART coupled with a FTDI USB-to-TTL chip, then use rxtx to access the resulting serial port on "100+" platforms.

This approach seem to work well: communicating and programming the arduino is very easy under Linux, Windows, and OS X.

Answer 2

First the disclaimer: I have not done this with a PIC and Java, only with an AVR32B with VB on the pc.

If you implement a USB CDC class device on the microcontroller USB interface and connect it to your pc USB HOST it will enumerate and appear as a new COM: port. This is then treated by the application as a normal serial port. I used the standard windows driver USBSER.SYS.

I presume that microchip provide example source code for their USB peripheral to allow it to operate in different device classes. (I know that Atmel do for the AVR32 families)

Answer 3

Why did you accept the answer above? I agree with @Ian's comment there.

The PIC18F4550 and its friends have onboard USB. It is easy and there are plenty of examples out there to put a virtual serial port in the PIC firmware. Another other is an HID device, again plenty of PIC firmware examples.

Don't add more hardware to the pudding.

Answer 4

You need to use JNI to make calls to the WIN32API directly. I was using JNA (JNI wrapper) library to make the implementation easy and made a DLL to export easier and direct methods in Visual C++ 2010. You can also create other libraries (DLL/SO) using the same interface to other systems like OSX and Linux.