init

2026-08-27 08:00:29 +00:00 · 2017-06-14 17:45:55 +03:00
parent 42182efc61
commit d947c58703
8 changed files with 984 additions and 0 deletions
@@ -0,0 +1,447 @@
+/*
+  AVCLanDrv.cpp v.01 - AVCLan Library for 'duino / Wiring
+  Created by Kochetkov Aleksey, 30.06.2009
+*/
+
+#include "AVCLanDrv.h"
+#include "BuffSerial.h"
+
+// AVCLan driver & timer2 init, 
+void AVCLanDrv::begin (){
+	// AVCLan TX+/TX- 	read line INPUT
+	cbi(DATAIN_DDR,  DATAIN);
+#ifdef AVCLAN_ST485
+	sbi(DATAIN_PORT, DATAIN);
+#else 
+	cbi(DATAIN_PORT, DATAIN);
+#endif
+
+	// AVCLan TX+/TX-		write line OUTPUT	
+#ifdef AVCLAN_RESISTOR
+	cbi(DATAOUT_DDR,  DATAOUT);
+	cbi(DATAOUT_PORT, DATAOUT);
+	cbi(ADCSRB, ACME);	// Analog Comparator Multiplexer Enable - NO
+	cbi(ACSR, ACIS1);	// Analog Comparator Interrupt Mode Select
+	cbi(ACSR, ACIS0);  // Comparator Interrupt on Output Toggle
+	cbi(ACSR, ACD); 	// Analog Comparator Disbale - NO
+#else 
+	sbi(DATAOUT_DDR,  DATAOUT);
+	sbi(OUTEN_DDR,  OUTEN);
+	AVC_OUT_DIS;
+	OUTPUT_SET_0;
+#endif
+	// timer2 setup, prescaler factor - 8
+#if defined(__AVR_ATmega8__)
+//	ASSR=0x00;
+	TCCR2=0x02;
+//	TCNT2=0x00;
+//	OCR2=0x00;
+#else   // ATMega168
+//	ASSR=0x00;
+//	TCCR2A=0x00;
+	TCCR2B=0x02;
+//	TCNT2=0x00;
+//	OCR2A=0x00;
+//	OCR2B=0x00;
+#endif
+	deviceAddress = 0x0000;
+}
+
+// Reads specified number of bits from the AVCLan.
+// nbBits (byte) -> Number of bits to read.
+// Return (word) -> Data value read.
+word AVCLanDrv::readBits (byte nbBits){
+	word data  = 0;
+	_parityBit = 0;
+	
+	while (nbBits-- > 0){
+		// Insert new bit
+		data <<= 1;
+		// Wait until rising edge of new bit.
+		while (INPUT_IS_CLEAR){
+			// Reset watchdog.
+			//wdt_reset();
+		}
+
+		// Reset timer to measure bit length.
+		TCNT2 = 0;
+		// Wait until falling edge.
+		while (INPUT_IS_SET);
+		// Compare half way between a '1' (20 us) and a '0' (32 us ): 32 - (32 - 20) /2 = 26 us
+		if (TCNT2 < AVC_BIT_0_HOLD_ON_MIN_LENGTH){
+			// Set new bit.
+			data |= 0x0001;
+			// Adjust parity.
+			_parityBit = ! _parityBit;
+		}
+	}
+	return data;
+}
+
+// Read incoming messages on the AVCLan.
+// Return true if success.
+byte AVCLanDrv::readMessage (){
+	uint8_t t = 0;
+	uint8_t oldSREG = SREG;
+	cli();             // disable interrupts
+
+	// Start bit.
+	while (INPUT_IS_CLEAR);
+	TCCR2B=0x03;      // prescaler 32
+	TCNT2 = 0;
+	// Wait until falling edge.
+	while (INPUT_IS_SET){
+		t = TCNT2;
+		if (t > 0xFF) {
+			SREG = oldSREG;
+			return 1;
+		}
+	}
+	TCCR2B=0x02;      // prescaler 8
+	
+	if (t < AVC_START_BIT_HOLD_ON_MIN_LENGTH){
+	//if (t < 0x16){
+			SREG = oldSREG;
+			return 2;
+	}
+
+	broadcast = readBits(1);
+
+	masterAddress = readBits(12);
+	bool p = _parityBit;
+	if (p != readBits(1)){
+		SREG = oldSREG;
+		return 3;
+	}
+  
+	slaveAddress = readBits(12);       
+	p = _parityBit;
+	if (p != readBits(1)){
+		SREG = oldSREG;
+		return 4;
+	}
+
+	bool forMe = ( slaveAddress == deviceAddress );
+
+	if (forMe){
+		// Send ACK.
+		send1BitWord(0);
+	}else{  
+		readBits(1);
+	}
+
+	// Control 
+	readBits(4);
+	p = _parityBit;
+	if (p != readBits(1)){
+		SREG = oldSREG;
+		return 5;
+	}
+
+	if (forMe){
+		// Send ACK.
+		send1BitWord(0);
+	}else{  
+		readBits(1);
+	}
+
+	dataSize = readBits(8);
+	p = _parityBit;
+	if (p != readBits(1)){
+		SREG = oldSREG;
+		return 6;
+	}
+
+	if (forMe){
+		// Send ACK.
+		send1BitWord(0);
+	}else{  
+		readBits(1);
+	}
+	if (dataSize > AVC_MAXMSGLEN){
+		SREG = oldSREG;
+		return 7;
+	}
+	byte i;
+	for (i = 0; i < dataSize; i++ ){
+		message[i] = readBits(8);
+		p = _parityBit;
+		if (p != readBits(1)){
+			SREG = oldSREG;
+			return 8;
+		}
+
+		if (forMe){
+			// Send ACK.
+			send1BitWord(0);
+		}else{  
+			readBits(1);
+		}
+	}
+	SREG = oldSREG;
+	return 0;   
+}
+
+// Send a start bit to the AVCLan
+void AVCLanDrv::sendStartBit (){
+	// Reset timer to measure bit length.
+	TCCR2B=0x03;      // prescaler 32
+	TCNT2 = 0;
+	OUTPUT_SET_1;
+
+	// Pulse level high duration.
+	while ( TCNT2 < AVC_START_BIT_HOLD_ON_LENGTH );
+	OUTPUT_SET_0;
+
+	// Pulse level low duration until ~185 us.
+	while ( TCNT2 < AVC_START_BIT_LENGTH );
+	TCCR2B=0x02;      // prescaler 8
+
+}
+
+// Send a 1 bit word to the AVCLan
+void AVCLanDrv::send1BitWord (bool data){
+	// Reset timer to measure bit length.
+	TCNT2 = 0;
+	OUTPUT_SET_1;
+
+	if (data){
+		while (TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH);
+	}else{
+		while (TCNT2 < AVC_BIT_0_HOLD_ON_LENGTH);
+	}
+
+	OUTPUT_SET_0;
+	while (TCNT2 <  AVC_NORMAL_BIT_LENGTH);
+}
+
+// Send a 4 bit word to the AVCLan
+void AVCLanDrv::send4BitWord (byte data){
+	_parityBit = 0;
+
+	// Most significant bit out first.   
+	for ( char nbBits = 0; nbBits < 4; nbBits++ ){
+		// Reset timer to measure bit length.
+		TCNT2 = 2;
+		OUTPUT_SET_1;
+
+		if (data & 0x8){
+			// Adjust parity.
+			_parityBit = ! _parityBit;
+			while ( TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH );
+		}else{
+			while ( TCNT2 < AVC_BIT_0_HOLD_ON_LENGTH );
+		}
+
+		OUTPUT_SET_0;
+		// Hold output low until end of bit.
+		while ( TCNT2 < AVC_NORMAL_BIT_LENGTH );
+
+		// Fetch next bit.
+		data <<= 1;
+	}
+}
+
+// Send a 8 bit word to the AVCLan
+void AVCLanDrv::send8BitWord (byte data){
+	_parityBit = 0;
+
+	// Most significant bit out first.   
+	for ( char nbBits = 0; nbBits < 8; nbBits++ ){
+		// Reset timer to measure bit length.
+		TCNT2 = 2;
+		OUTPUT_SET_1;
+
+		if (data & 0x80){
+			// Adjust parity.
+			_parityBit = ! _parityBit;
+			while ( TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH );
+		}else{
+			while ( TCNT2 < AVC_BIT_0_HOLD_ON_LENGTH );
+		}
+
+		OUTPUT_SET_0;
+		// Hold output low until end of bit.
+		while ( TCNT2 < AVC_NORMAL_BIT_LENGTH );
+
+		// Fetch next bit.
+		data <<= 1;
+	}
+}
+
+// Send a 12 bit word to the AVCLan
+void AVCLanDrv::send12BitWord (word data){
+	_parityBit = 0;
+
+	// Most significant bit out first.   
+	for ( char nbBits = 0; nbBits < 12; nbBits++ ){
+		// Reset timer to measure bit length.
+		TCNT2 = 2;
+		OUTPUT_SET_1;
+
+		if (data & 0x0800){
+			// Adjust parity.
+			_parityBit = ! _parityBit;
+			while ( TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH );
+		}else{
+			while ( TCNT2 < AVC_BIT_0_HOLD_ON_LENGTH );
+		}
+
+		OUTPUT_SET_0;
+		// Hold output low until end of bit.
+		while ( TCNT2 < AVC_NORMAL_BIT_LENGTH );
+
+		// Fetch next bit.
+		data <<= 1;
+	}
+}
+
+//  determine whether the bus is free (no tx/rx).
+//  return TRUE is bus is free.
+bool AVCLanDrv::isAvcBusFree (void){
+	// Reset timer.
+	TCNT2 = 0;
+
+	while (INPUT_IS_CLEAR){
+		// We assume the bus is free if anything happens for the length of 1 bit.
+		if (TCNT2 > AVC_NORMAL_BIT_LENGTH){   
+			return true;
+		}
+	}
+    
+	return false;
+}
+
+// reads the acknowledge bit the AVCLan
+// return TRUE if ack detected else FALSE.
+bool AVCLanDrv::readAcknowledge (void){
+	// The acknowledge pattern is very tricky: the sender shall drive the bus for the equivalent
+	// of a bit '1' (20 us) then release the bus and listen. At this point the target shall have
+	// taken over the bus maintaining the pulse until the equivalent of a bit '0' (32 us) is formed.
+
+	// Reset timer to measure bit length.
+	TCNT2 = 0;
+	OUTPUT_SET_1;
+
+	// Generate bit '0'.
+	while (TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH);
+	OUTPUT_SET_0;
+	
+	AVC_OUT_DIS;
+	
+	while (TCNT2 < AVC_BIT_1_HOLD_ON_LENGTH + AVC_1U_LENGTH);
+	// Measure final resulting bit.
+	while ( INPUT_IS_SET );
+
+	// Sample half-way through bit '0' (26 us) to detect whether the target is acknowledging.
+	if (TCNT2 > AVC_BIT_0_HOLD_ON_MIN_LENGTH){
+		// Slave is acknowledging (ack = 0). Wait until end of ack bit.
+		while (INPUT_IS_SET );
+		AVC_OUT_EN;
+		return true;
+	}
+
+	// No sign of life on the bus.
+	return false;    
+}
+
+// sends ack bit if I am broadcasting otherwise wait and return received ack bit.
+// return FALSE if ack bit not detected.
+bool AVCLanDrv::handleAcknowledge (void){
+	if (broadcast == AVC_MSG_BROADCAST){   
+		// Acknowledge.    
+		send1BitWord(0);
+		return true;
+	}
+
+	// Return acknowledge bit.
+	return readAcknowledge();
+} 
+
+// sends the message in global registers on the AVC LAN bus.
+// return TRUE if successful else FALSE.
+byte AVCLanDrv::sendMessage (void){  
+	uint8_t oldSREG = SREG;
+	cli();             // disable interrupts
+	while (!isAvcBusFree());
+	
+	AVC_OUT_EN;
+	
+	// Send start bit.
+	sendStartBit();
+
+	// Broadcast bit.
+	send1BitWord(broadcast);
+
+	// Master address = me.
+	send12BitWord(masterAddress);
+	send1BitWord(_parityBit);
+
+	// Slave address = head unit (HU).
+	send12BitWord(slaveAddress);
+	send1BitWord(_parityBit);
+	if (!handleAcknowledge()){
+		AVC_OUT_DIS;
+		SREG = oldSREG;
+		return 1;
+	}
+
+	// Control flag + parity.
+	send4BitWord(AVC_CONTROL_FLAGS);
+	send1BitWord(_parityBit);
+	if (!handleAcknowledge()){
+		AVC_OUT_DIS;
+		SREG = oldSREG;
+		return 2;
+	}
+
+	// Data length + parity.
+	send8BitWord(dataSize);
+	send1BitWord(_parityBit);
+	if (!handleAcknowledge()){
+		AVC_OUT_DIS;
+		SREG = oldSREG;
+		return 3;
+	}
+
+	for (byte i = 0; i < dataSize; i++){
+		send8BitWord(message[i]);
+		send1BitWord(_parityBit);
+		if (!handleAcknowledge()){
+			AVC_OUT_DIS;
+			SREG = oldSREG;
+			return false;
+		}
+	}
+	AVC_OUT_DIS;
+	SREG = oldSREG;
+	return 0;
+}
+
+// print message to serial
+void AVCLanDrv::printMessage(bool incoming){
+	if (incoming){
+		bSerial.print("< ");
+	}else{
+		bSerial.print("> ");
+	}  
+	if (broadcast == AVC_MSG_BROADCAST){
+		bSerial.print("b ");
+	}else{ 
+		bSerial.print("d ");
+	}
+	bSerial.printHex4(masterAddress >> 8);
+	bSerial.printHex8(masterAddress);
+	bSerial.print(" ");
+
+	bSerial.printHex4(slaveAddress >> 8);
+	bSerial.printHex8(slaveAddress);
+	bSerial.print(" ");
+	bSerial.printHex8(dataSize);
+
+	for (byte i = 0; i < dataSize; i++){
+		bSerial.printHex8(message[i]);
+	}
+	bSerial.println(); 
+
+}