INTRO The Clicker board is a perfect "XS size" development board to play with the large and intriguing array of Click boards. There is only one thing that it is missing (to be perfect) and that is a simple communication interface to enable experimenting to begin from the desktop.  I wanted it to be cross-platform and easily extensible, ideally interactive from a command line. I want to experiment with the features of each specific click board without having to develop a complete embedded control project each time, compile, program load, debug (and repeat). A faster development cycle  can truly unleash creativity. So my primary goal was to access the Clicker communication interfaces (I2C, SPI, UART and I/Os) from a simple USB-HID class command protocol. Once the command interpreter firmware is loaded on the PIC18F47J53,  Python scripts, but also Visual Basic and of course C/C++ applications (using the cross platrform HIDAPI open source library) can access directly the mikro-bus.  Some example scripts have been included in this project to demonstrate how in a few lines of code (Python) we can control one of the LED matrix click boards (see testRED.py), build a GUI and/or activate 10 PWM outputs (see testPWM.py).  

REQUIREMENTS The main firmware project requires:

• MPLAB X (v.2.0 and above, free)
• MPLAB C18 compiler (free)  
• MLA v. 2013-06-15 (previous versions ok, do not use the 2013-12 or later)
• Python 2.6 or 2.7 
• HIDAPI library (Python or C for the desktop platform of choice, MAC, Windows, Linux) 

 Enjoy and feel free to suggest and/or implement your improvements!        

 PROTOCOL The communication protocol adopted is extremely simple and based on a Full Speed HID class link established during enumeration of the Clicker board. Subsequently for each received packet of 64 bytes received by the clicker board:

• The first byte is used to discriminate the command. Commands are grouped logically by communication interface (I2C, Serial...)
• If recognized, after execution a response packet is returned to the PC with the same command in the first position
• If not recognized or if execution failed, a packet with 0xFF in the first position is returned 
•  

INSTALLATION

There are several components that are required to get a complete demo working, here the short version:

Building the executable from the MPLAB X project source 

(Note: you can bypass this step by loading directly the hex file, second attachment, onto the Clicker board)

1- Install the MLA release 2013-06-15 or prior(!),

2- Copy the /Microchip folder (or create a simlink on MAC/Linux) inside the same working directory where you unzipped the project package (.zip) as in: 

/working_directory

..../Click-API

..../Microchip

3- Build and program the resulting .Hex file into the PIC18

Installing the HIDAPI libraries for your OS and language of choice

If you have never used the HIDAPI libraries (this is an open source project created and maintained by Signal 11) you will need to obtain the correct version for you programming language of choice:

- Obtain the Python HIDAPI library from: https://pypi.python.org/pypi/hidapi and follow the instructions contained to build and install on your OS.

- Obtain the C/C++ HIDAPI library from: https://github.com/signal11/hidapi/downloads