A Basic iButton Interface

#include "StdAfx.h"
#include "buttonInterface.h"

// 1-wire iButton Interface Example
// Identifying iButtons in a worker thread without colliding with application thread nvram read/write operations

/*
file:///C:/Program%20Files/Dallas%20Semiconductor/1-Wire%20SDK%20V4.00%20Beta/Docs/TMEX/tmwi5ur7.html

Windows 95 98 and Me

Type#     Port               Driver Name                Description
1            COM             IB97E32.DLL              uses the DS9097E adapter on COM ports
2            LPT                IB10E32.DLL             uses the DS1410E adapter on LPT ports
5            COM             IB97U32.DLL             uses the DS9097U adapter on COM ports
6            USB               IB90USB.DLL            uses the DS1490 adapter on USB ports (compatible with Windows 98 and Me only)

Windows NT 2000 XP
Type#    Port                Driver Name                Description
1            COM             IB97E32.DLL              uses the DS9097E adapter on COM ports
2            LPT               IB10E32.DLL               uses the DS1410E adapter on LPT ports
5            COM             IB97U32.DLL              uses the DS9097U adapter on COM ports
6            USB               IB90USB.DLL             uses the DS1490 adapter on USB ports (compatible with 2000 and XP only)

*/

ButtonInterface::ButtonInterface(void) : hSess(0), endMonitor(false), pauseMonitor(false), monitorActive(false)
{
	InitializeCriticalSection(&cs);
	notificationAdded=RegisterWindowMessage("iButtonNotification_ButtonAdded");
	notificationRemoved=RegisterWindowMessage("iButtonNotification_ButtonRemoved");
	QueryPerformanceFrequency(&freq);

	hInst = LoadLibrary("IBFS32.DLL");

	if (hInst != NULL)
	{
	     TMExtendedStartSession=(long (far pascal *)(short,short,void far *))GetProcAddress(hInst, "TMExtendedStartSession");
		TMReadDefaultPort=(short (far pascal *)(short far*, short far*))GetProcAddress(hInst, "TMReadDefaultPort");
		TMSetup=(short (far pascal *)(long))GetProcAddress(hInst, "TMSetup");
		TMEndSession=(short (far pascal *)(long))GetProcAddress(hInst, "TMEndSession");

		TMFirst=(short (far pascal *)(long, void far*))GetProcAddress(hInst, "TMFirst");
		TMNext=(short (far pascal *)(long, void far*))GetProcAddress(hInst, "TMNext");

		TMRom=(short (far pascal *)(long, void far*, short far*))GetProcAddress(hInst, "TMRom");
		TMAccess=(short (far pascal *)(long, void far*))GetProcAddress(hInst, "TMAccess");
		TMStrongAccess=(short (far pascal *)(long, void far*))GetProcAddress(hInst, "TMStrongAccess");

		TMTouchByte=(short (far pascal *)(long, short))GetProcAddress(hInst, "TMTouchByte");
		TMBlockStream=(short (far pascal *)(long, unsigned char far*, short))GetProcAddress(hInst, "TMBlockStream");

		// nvram devices only
		TMWritePacket=(short (far pascal *)(long, void far*, short, unsigned char far*, short))GetProcAddress(hInst, "TMWritePacket");
		TMReadPacket=(short (far pascal *)(long, void far*, short, unsigned char far*, short))GetProcAddress(hInst, "TMReadPacket");
	}
}

ButtonInterface::~ButtonInterface(void)
{
	endMonitor=true;
	while (monitorActive) {};
	FreeLibrary(hInst);
	DeleteCriticalSection(&cs);
}


bool ButtonInterface::StartSession(void)
{
	if (hInst != NULL)
	{
		short portNum;
		short portType;
		TMReadDefaultPort(&portNum, &portType);
		hSess=TMExtendedStartSession(portNum, portType, NULL);
		if (hSess != 0)
		{
			// must be called before any non-session functions can be called
			TMSetup(hSess);
		}
	}
	return hSess != 0;
}


void ButtonInterface::EndSession(void)
{
	if (hSess > 0)
	{
		endMonitor=true;
		while (monitorActive) {};
		TMEndSession(hSess);
		hSess=NULL;
	}
}


void ButtonInterface::StartMonitor(int msSleep, int debounce)
{
	if (hSess > 0)
	{
		sleepTime=msSleep;
		debounceTime=debounce;
		AfxBeginThread(MonitorThreadStartup, this);
	}
}

UINT ButtonInterface::MonitorThreadStartup(void* v)
{
	ButtonInterface* btn=(ButtonInterface*)v;
	btn->Monitor();
	return 0;
}

void ButtonInterface::BeginIO(void)
{
	EnterCriticalSection(&cs);
}


void ButtonInterface::EndIO(void)
{
	LeaveCriticalSection(&cs);
}

bool ButtonInterface::SelectDevice(CString romCode)
{
	short ROM[9];							// leave room for 32 bit value
	for (int i=7; i>=0; i--)
	{
		CString hex=romCode.Mid(i*2, 2);
		sscanf(hex, "%02X", &ROM[7-i]);
	}
	TMRom(hSess, stateBuffer, ROM);
	int n=TMAccess(hSess, stateBuffer);
	return n==1;
}

bool ButtonInterface::SelectDeviceStrong(CString romCode)
{
	short ROM[9];							// leave room for 32 bit value
	for (int i=7; i>=0; i--)
	{
		CString hex=romCode.Mid(i*2, 2);
		sscanf(hex, "%02X", &ROM[7-i]);
	}
	TMRom(hSess, stateBuffer, ROM);
	int n=TMStrongAccess(hSess, stateBuffer);
	return n==1;
}

bool ButtonInterface::ReadPage(int page, unsigned char* data, int len)
{
	if (len > 32) return false;
	TMAccess(hSess, stateBuffer);
	TMTouchByte(hSess, 0xF0);
	TMTouchByte(hSess, (short)((page*32)&0xFF));
	TMTouchByte(hSess, (short)((page*32)>>8));
	for (int i=0; i<len; i++)
	{
		data[i]=(unsigned char)TMTouchByte(hSess, 0xFF);
	}
	return true;
}

bool ButtonInterface::WritePage(int page, unsigned char* data, int len)
{
	if (len > 32) return false;
	// write to scratchpad
	TMAccess(hSess, stateBuffer);
	TMTouchByte(hSess, 0x0F);
	TMTouchByte(hSess, (short)((page*32)&0xFF));
	TMTouchByte(hSess, (short)((page*32)>>8));
	TMBlockStream(hSess, data, (short)len);

	// get target address and ending offset/data status byte
	TMAccess(hSess, stateBuffer);
	TMTouchByte(hSess, 0xAA);
	unsigned char auth[3];
	for (int i=0; i<3; i++)
	{
		auth[i]=(unsigned char)TMTouchByte(hSess, 0xFF);
	}

	// copy scratchpad to memory
	TMAccess(hSess, stateBuffer);
	TMTouchByte(hSess, 0x55);
	for (int i=0; i<3; i++)
	{
		TMTouchByte(hSess, auth[i]);
	}
	return true;
}

int ButtonInterface::GetButtonList(CString* codes)
{
	short ret=TMFirst(hSess, stateBuffer);
	int n=0;
	while ( (ret==1) && (n<32) )
	{
		// if MSB of ROM[0] != 0, then write, else read
		short ROM[8]={0, 0, 0, 0, 0, 0, 0, 0};
		TMRom(hSess, stateBuffer, ROM);

		// convert the ROM code into a string
		char s[3]="\0\0";
		CString romCode="";
		for (int i=7; i>=0; i--)
		{
			sprintf(s, "%02X", ROM[i]);
			romCode+=s;
		}
		codes[n]=romCode;
		++n;
		ret=TMNext(hSess, stateBuffer);
	}
	return n;
}

void ButtonInterface::Monitor(void)
{
	CString* codes=new CString[32];
	monitorActive=true;
	while (!endMonitor)
	{
		Sleep(sleepTime);
		if (pauseMonitor)
		{
			continue;
		}
		EnterCriticalSection(&cs);

		// untouch all buttons in list
		std::map<CString, ButtonInfo>::iterator iter=buttonInfo.begin();
		while (iter != buttonInfo.end())
		{
			(*iter).second.touched=false;
			++iter;
		}

		int numButtons=GetButtonList(codes);

		// touch all found devices
		for (int i=0; i<numButtons; i++)
		{
			CString romCode=codes[i];
			iter=buttonInfo.find(romCode);
			if (iter != buttonInfo.end())
			{
				(*iter).second.touched=true;
				QueryPerformanceCounter(&(*iter).second.currentSampleTime);
			}
			else
			{
				buttonInfo[romCode]=ButtonInfo();
			}
		}

		// Debounce all activity
		// 1.  If a button is new, then issue an add notification immediately
		// 2.  If a button hasn't been "touched" for the debounce time, then issue a remove notification
		LARGE_INTEGER sampleTime;
		QueryPerformanceCounter(&sampleTime);
		iter=buttonInfo.begin();
		while (iter != buttonInfo.end())
		{
			CString code=(*iter).first;
			ButtonInfo& bi=(*iter).second;
			if (bi.newButton)
			{
				PostNotification(notificationAdded, (*iter).first);
				bi.newButton=false;
			}
			else
			if (bi.touched==false)
			{
				if (sampleTime.QuadPart-bi.currentSampleTime.QuadPart > freq.QuadPart*debounceTime/1000)
				{
					PostNotification(notificationRemoved, (*iter).first);
					buttonInfo.erase(iter);
					break;
				}
			}
			++iter;
		}

		LeaveCriticalSection(&cs);
	}
	endMonitor=false;
	delete[] codes;
	monitorActive=false;
}


void ButtonInterface::PostNotification(UINT msg, CString code)
{
	CString* data=new CString(code);
	AfxGetApp()->PostThreadMessage(msg, 0, (LPARAM)data);
}