WiiClassicController.cpp

00001 /*
00002  * SOURCE FILE : WiiClassicController.cpp
00003  *
00004  * Definition of class WiiClassicController.
00005  * Allows use of a Wii classic controller using an I2C bus.
00006  *
00007  */
00008 
00009 #include "WiiClassicController.h"
00010 
00011 // Delay to slow things down. Doesn;t work without this.
00012 #define WAIT_TIME ((float)0.01 )    // in seconds
00013 
00014 /** Constructor.
00015  * @param sda pin to use for SDA.
00016  * @param scl pin to use for SCL.
00017  */
00018 WiiClassicController::WiiClassicController( PinName sda, PinName scl ) :
00019     controllerPort( sda, scl ),
00020     initialised( false )
00021 {
00022 }
00023 
00024 /** Destructor.
00025  */
00026 WiiClassicController::~WiiClassicController() {
00027 }
00028 
00029 /** Read from the controller.
00030  * @returns true on success, false on failure.
00031  */
00032 bool WiiClassicController::Read( void ) {
00033     // Don't expect client to remember to send an init to the nunchuck
00034     // so do it for them here.
00035     if( ! initialised ) {
00036         initialised = ControllerInit();
00037     }
00038     // Don't start reading if init failed
00039     return initialised && ControllerRead();
00040 }
00041 
00042 /** Initialise the controller.
00043  * @returns true on success, false on failure.
00044  */
00045 bool WiiClassicController::ControllerInit( void ) {
00046     const UInt8 cmd[] = { CONTROLLER_REGADDR, 0x00 };
00047     bool ok = ( controllerPort.write( CONTROLLER_ADDR, (const char*)cmd, sizeof(cmd) ) == 0 );
00048     wait( WAIT_TIME );
00049     return ok;
00050 }
00051 
00052 /** Read from the controller, assuming it has been initialised.
00053  * @returns true on success, false on failure.
00054  */
00055 bool WiiClassicController::ControllerRead() {
00056     bool ok = false;
00057     // write the address we want to read from
00058     const UInt8 cmd[] = { 0x00 };
00059     if( controllerPort.write( CONTROLLER_ADDR, (const char*)cmd, sizeof(cmd) ) == 0 ) {
00060         // The Wii Classic Controller is non-standard I2C
00061         // and can't manage setting the read address and immediately supplying the data
00062         // so wait a bit.
00063         wait( WAIT_TIME );
00064         if( controllerPort.read( CONTROLLER_ADDR, (char*)readBuf, sizeof(readBuf) ) == 0 ) {
00065             for( int i = 0; i < CONTROLLER_READLEN; ++i ) {
00066                 readBuf[ i ] = Decode( readBuf[ i ] );
00067             }
00068             ok = true;
00069         }
00070     }
00071     // wait( WAIT_TIME );
00072     return ok;
00073 }