at.c

AVR单片机系统开发经典实例部分源程序

// this bit takes care of the AT modem dialing etc

/*
 * Copyright (C) 2003-2004 by Clive Moss All rights reserved.
 *
 * Help & Contributions from D.J.Armstrong

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY CLIVE MOSS 'AS IS' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.
 * IN NO EVENT SHALL CLIVE MOSS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL,SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

//#ifdef CPU_eZ8
//	#pragma stkck									// enable stack checking
//#endif

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>

#include "common.h"
#include "at.h"
#include "ppp.h"

//*************************************************************************************

#ifdef Debug
flash char	ATStageStr1[]	=	"\n*** AT Stage: ";
flash char	ATStageStr2[]	=	"Idle\n";
flash char	ATStageStr3[]	=	"Dial Init 1\n";
flash char	ATStageStr4[]	=	"Dial Init 2\n";
flash char	ATStageStr5[]	=	"Dial Init 3\n";
flash char	ATStageStr6[]	=	"Dialing\n";
flash char	ATStageStr7[]	=	"PPP\n";
flash char	ATStageStr8[]	=	"Disc 1\n";
flash char	ATStageStr9[]	=	"Disc 2\n";
flash char	ATStageStr10[]	=	"Unknown\n";
flash char	ATStageStr20[]	=	"*** AT Retry Fail\n";
flash char	ATDialTermStr[]	=	"AT\n";
#endif

T_AT		AT;

//*************************************************************************************

#ifdef Debug

bool AT_DisplayStage(void)
{
	if(!SendDebugRStr(ATStageStr1)) return false;
	switch (AT.Stage)
	{
		case AT_Idle		:	return SendDebugRStr(ATStageStr2);
		case AT_DialInit1	:	return SendDebugRStr(ATStageStr3);
		case AT_DialInit2	:	return SendDebugRStr(ATStageStr4);
		case AT_DialInit3	:	return SendDebugRStr(ATStageStr5);
		case AT_Dial		:	return SendDebugRStr(ATStageStr6);
		case AT_PPP			:	return SendDebugRStr(ATStageStr7);
		case AT_Disc1		:	return SendDebugRStr(ATStageStr8);
		case AT_Disc2		:	return SendDebugRStr(ATStageStr9);
		default				:	return SendDebugRStr(ATStageStr10);
	}
}

#endif

//*************************************************************************************

void AT_Stage(T_AT_Stage Stage)
{	// set the AT modem stage
	if (AT.Stage == Stage) return;	// no change
									//
	AT.Stage = Stage;				//
	AT.Retries = 0;					//
	u16_Put(&AT.Retry_Timer, 0);	// send next thing asap

	#ifdef Debug
		AT_DisplayStage();
	#endif
}

bool AT_Start(void)
{	// start a connection attempt
	// call this from the executive when you want to connect
	if (AT.Stage != AT_Idle) return false;				// already busy with the modem
	#ifdef WindowsPPP
		AT_Stage(AT_PPP);								//
		PPP_Start(PPP_Rom_Username, PPP_Rom_Password);	// start a PPP session
		return true;									//
	#else
		AT_Stage(AT_DialInit1);							//
														//
		MainBufferWr_Rx = 0;							//
		MainBufferWr_Tx = 0;							//
		UART1_RxBufferRd = 0;							//
		UART1_RxBufferWr = 0;							//
														//
		return true;									//
	#endif
}

void AT_End(void)
{	// terminate a connection
	if (PPP.Stage != PPPS_None)
	{	// terminate the PPP first
		PPP_End();
		return;
	}

	#ifdef WindowsPPP
		AT_Stage(AT_Idle);
	#else
		switch (AT.Stage)
		{
			case AT_Idle		:	break;
			case AT_DialInit1	:	AT_Stage(AT_Idle);
									break;
			case AT_DialInit2	:	AT_Stage(AT_Idle);
									break;
			case AT_DialInit3	:	AT_Stage(AT_Idle);
									break;
			case AT_Dial		:	AT_Stage(AT_Disc2);
									break;
			case AT_PPP			:	PPP_End();
									break;
			case AT_Disc1		:	break;				// already trying to disconnect
			case AT_Disc2		:	break;				// already trying to disconnect
			default				:	AT_Stage(AT_Idle);
									break;
		}
	#endif
}

//*************************************************************************************
// call this when we have a new byte received from the modem - call from the executive

void AT_AddNewRxByte(u8 c)
{
	#ifndef WindowsPPP
		bool	ok = false;
		bool	error = false;
		bool	ring = false;
		bool	failed = false;
		bool	connect = false;

		if (c != 13)
		{
			if (c < 32) return;											// ignore control charcters
			if (MainBufferWr_Rx >= (sizeof(MainBuffer) - 1)) return;	// buffer overflow - ignore character
			if (MainBufferWr_Rx < 0) MainBufferWr_Rx = 0;
			MainBuffer[MainBufferWr_Rx++] = tolower((char)c);
			MainBuffer[MainBufferWr_Rx] = 0;
			return;
		}

		// CR

		strtrim(MainBuffer, ' ');
		MainBufferWr_Rx = 0;

		if (MainBuffer[0] == 0) return;									// empty line

		#ifdef Debug
			SendDebugStr(MainBuffer);
			SendDebugStr("\n");
		#endif

		if (strcmp((char*)MainBuffer, "ok") == 0) ok = true;
		else
		if (strcmp((char*)MainBuffer, "error") == 0) error = true;
		else
		if (strcmp((char*)MainBuffer, "ring") == 0) ring = true;
		else
		if (strcmp((char*)MainBuffer, "busy") == 0) failed = true;
		else
		if (strcmp((char*)MainBuffer, "no dialtone") == 0) failed = true;
		else
		if (strcmp((char*)MainBuffer, "no answer") == 0) failed = true;
		else
		if (strcmp((char*)MainBuffer, "no carrier") == 0) failed = true;
		else
		if ((strlen((char*)MainBuffer) >= 7) && (strncmp((char*)MainBuffer, "connect", 7) == 0)) connect = true;

		memset(MainBuffer, 0, sizeof(MainBuffer));

		if ((AT.Stage != AT_Dial) && failed)
		{
			AT_Stage(AT_Idle);
			return;
		}

		switch (AT.Stage)
		{
			case AT_DialInit1	:	if (ok) AT_Stage(AT_DialInit2);
									break;
			case AT_DialInit2	:	if (ok) AT_Stage(AT_DialInit3);
									break;
			case AT_DialInit3	:	if (ok) AT_Stage(AT_Dial);
									break;
			case AT_Dial		:	if (failed || error)
									{
										u16_Put(&AT.Retry_Timer, AT_Dial_Retry_Time);				// try again in 6 seconds
										break;
									}
			case AT_Idle		:	if (connect)
									{
										AT_Stage(AT_PPP);
										PPP_Start(PPP_Rom_Username, PPP_Rom_Password);		// start a PPP session
									}
									break;
			case AT_PPP			:	break;													// PPP is using the modem
			case AT_Disc1		:	if (ok || error) AT_Stage(AT_Disc2);					// the modem has come out of data mode - we used the '+++' thingy
									break;
			case AT_Disc2		:	if (ok) AT_Stage(AT_Idle);								// the modem accepted the hangup command(s)
									break;
			default				:	AT_Stage(AT_Idle);
									break;
		}
	#endif
}

//*************************************************************************************
// call this every 10ms - say from a timer interrupt

void AT_10ms_Timer(void)
{	// call this every 10ms
	#ifndef WindowsPPP
		if (AT.Stage == AT_Idle) return;

		if (AT.Retry_Timer >= 10)
			AT.Retry_Timer -= 10;
		else
			AT.Retry_Timer = 0;
	#endif
}

//*************************************************************************************
// call this as often as possible from your executive loop - NOT from an interrupt
// it takes care of all the AT modem stuff for you

void AT_Process(void)
{
	u8	c;

	#ifdef WindowsPPP
															//
		if (PPP.Stage != PPPS_None) return;					//
															//
		if (!MainBufferWr_Tx)
		{
			while (UART1_RxBufferRd != UART1_RxBufferWr)
			{
				c = (u8)UART1_RxBuffer[UART1_RxBufferRd++];													// get rx'ed byte
				if (UART1_RxBufferRd >= sizeof(UART1_RxBuffer)) UART1_RxBufferRd -= sizeof(UART1_RxBuffer);	// wap awound
				AT_AddNewRxByte(c);																			// pass the byte onto the AT RX routine
			}
		}

		#ifdef ModemHandShaking
		HardwareFlowControl(ModemUart);									// tell em to hold it - if need be
		#endif
																		//
		AT_Stage(AT_Idle);												//
	#else
		if (PPP.Stage != PPPS_None)				//
		{										//
			AT.Retries = 0;						//
			u16_Put(&AT.Retry_Timer, 0);		//
			return;								// PPP is busy
		}										//

		// **********************************
		// get any new data from the PPP uart

		if (!MainBufferWr_Tx)
		{
			while (UART1_RxBufferRd != UART1_RxBufferWr)
			{
				c = (u8)UART1_RxBuffer[UART1_RxBufferRd++];													// get rx'ed byte
				if (UART1_RxBufferRd >= sizeof(UART1_RxBuffer)) UART1_RxBufferRd -= sizeof(UART1_RxBuffer);	// wap awound
				AT_AddNewRxByte(c);																			// pass the byte onto the AT RX routine
			}
		}

		#ifdef ModemHandShaking
		HardwareFlowControl(ModemUart);									// tell em to stop sending data if our buffer is full
		#endif

		// **********************************

		if (AT.Stage == AT_Idle) return;								//
																		//
		if (u16_Get(&AT.Retry_Timer)) return;							// not time to retry
																		//
		if (AT.Retries >= AT_Retries)									//
		{																//
			#ifdef Debug
				SendDebugRStr(ATStageStr20);
			#endif

			AT_Stage(AT_Idle);											//
			return;														//
		}

		switch (AT.Stage)
		{
			case AT_Idle		:	break;
			case AT_DialInit1	:	SendModemRStr(DialInit1);
									u16_Put(&AT.Retry_Timer, AT_Timeout);
									AT.Retries++;
									#ifdef Debug
										SendDebugRStr(DialInit1);
									#endif
									break;
			case AT_DialInit2	:	SendModemRStr(DialInit2);
									u16_Put(&AT.Retry_Timer, AT_Timeout);
									AT.Retries++;
									#ifdef Debug
										SendDebugRStr(DialInit2);
									#endif
									break;
			case AT_DialInit3	:	SendModemRStr(DialInit3);
									u16_Put(&AT.Retry_Timer, AT_Timeout);
									AT.Retries++;
									#ifdef Debug
										SendDebugRStr(DialInit3);
									#endif
									break;
			case AT_Dial		:	SendModemRStr(DialStr);
									u16_Put(&AT.Retry_Timer, AT_Dial_Timeout);
									AT.Retries++;
									#ifdef Debug
										SendDebugRStr(DialStr);
									#endif
									break;
			case AT_PPP			:	AT_Stage(AT_Disc1);							// start disconnect sequence
									u16_Put(&AT.Retry_Timer, 2000);				// 2 second wait
									break;
			case AT_Disc1		:	SendModemStr("+++");						// get modem in command mode
									u16_Put(&AT.Retry_Timer, AT_Timeout);		//
									AT.Retries++;								//
									#ifdef Debug
										SendDebugStr("+++\n");
									#endif
									break;
			case AT_Disc2		:	SendModemStr("ATH\n");						// tell modem to hang up
									u16_Put(&AT.Retry_Timer, AT_Timeout);		//
									AT.Retries++;								//
									#ifdef Debug
										SendDebugStr("ATH\n");
									#endif
									break;
			default				:	AT_Stage(AT_Idle);
									break;
		}
	#endif

	// **********************************
}

//*************************************************************************************