Added a timeout value to the TWI_StartTransmission() function, within which the addressed device must respond.

Fixed TWI_StartTransmission() corrupting the contents of the GPIOR0 register.

6 files changed, 56 insertions, 30 deletions

diff --git a/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.h b/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.h
index 13db86e69..2d8e6df1e 100644
--- a/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.h
+++ b/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.h
@@ -56,6 +56,7 @@
 		#include <avr/io.h>

 		#include <stdbool.h>

 		#include <util/twi.h>

+		#include <util/delay.h>

 		

 	/* Enable C linkage for C++ Compilers: */

 		#if defined(__cplusplus)

@@ -131,10 +132,11 @@
 			/** Begins a master mode TWI bus communication with the given slave device address.

 			 *

 			 *  \param[in] SlaveAddress  Address of the slave TWI device to communicate with

+			 *  \param[in] TimeoutMS     Timeout period within which the slave must respond, in milliseconds

 			 *

 			 *  \return Boolean true if the device is ready for data, false otherwise

 			 */

-			bool TWI_StartTransmission(uint8_t SlaveAddress);

+			bool TWI_StartTransmission(uint8_t SlaveAddress, uint8_t TimeoutMS);

 

 	/* Disable C linkage for C++ Compilers: */

 		#if defined(__cplusplus)

diff --git a/LUFA/Drivers/Peripheral/TWI.c b/LUFA/Drivers/Peripheral/TWI.c
index 6028bbae9..eb513c454 100644
--- a/LUFA/Drivers/Peripheral/TWI.c
+++ b/LUFA/Drivers/Peripheral/TWI.c
@@ -7,39 +7,58 @@
 

 #include "TWI.h"

 

-bool TWI_StartTransmission(uint8_t SlaveAddress)

+bool TWI_StartTransmission(uint8_t SlaveAddress, uint8_t TimeoutMS)

 {

 	for (;;)

 	{

-		uint8_t IterationsRemaining = 50;

-		bool    BusCaptured = false;

+		bool     BusCaptured = false;

+		uint16_t TimeoutRemaining;

 

-		while (IterationsRemaining-- && !BusCaptured)

+		TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN));	

+

+		TimeoutRemaining = (TimeoutMS * 100);

+		while (TimeoutRemaining-- && !BusCaptured)

 		{

-			TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN));	

-			while (!(TWCR & (1 << TWINT)));

-				

-			switch (TWSR & TW_STATUS_MASK)

+			if (TWCR & (1 << TWINT))

 			{

-				case TW_START:

-				case TW_REP_START:

-					BusCaptured = true;

-					break;

-				case TW_MT_ARB_LOST:

-					continue;

-				default:

-					return false;

+				switch (TWSR & TW_STATUS_MASK)

+				{

+					case TW_START:

+					case TW_REP_START:

+						BusCaptured = true;

+						break;

+					case TW_MT_ARB_LOST:

+						TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN));	

+						continue;

+					default:

+						TWCR = (1 << TWEN);

+						return false;

+				}

 			}

+			

+			_delay_us(10);

 		}

 		

 		if (!(BusCaptured))

-		  return false;

-		  

+		{

+			TWCR = (1 << TWEN);

+			return false;

+		}

+		

 		TWDR = SlaveAddress;

 		TWCR = ((1 << TWINT) | (1 << TWEN));

-		while (!(TWCR & (1 << TWINT)));

 		

-		GPIOR0 = (TWSR & TW_STATUS_MASK);

+		TimeoutRemaining = (TimeoutMS * 100);

+		while (TimeoutRemaining--)

+		{

+			if (TWCR & (1 << TWINT))

+			  break;

+			  

+			_delay_us(10);

+		}

+		

+		if (!(TimeoutRemaining))

+		  return false;

 

 		switch (TWSR & TW_STATUS_MASK)

 		{

@@ -49,6 +68,6 @@ bool TWI_StartTransmission(uint8_t SlaveAddress)
 			default:

 				TWI_StopTransmission();

 				break;

-		}		  

+		}

 	}

 }

diff --git a/LUFA/ManPages/ChangeLog.txt b/LUFA/ManPages/ChangeLog.txt
index 14f1a2547..155afa099 100644
--- a/LUFA/ManPages/ChangeLog.txt
+++ b/LUFA/ManPages/ChangeLog.txt
@@ -15,9 +15,11 @@
   *  - AVRISP programmer project now has a more robust timeout system, allowing for a doubling of the software USART speed

   *    for PDI and TPI programming

   *  - Increased the speed of both software and hardware TPI/PDI programming modes of the AVRISP project

+  *  - Added a timeout value to the TWI_StartTransmission() function, within which the addressed device must respond

   *

   *  <b>Fixed:</b>

   *  - Fixed software PDI/TPI programming mode in the AVRISP project not correctly toggling just the clock pin

+  *  - Fixed TWI_StartTransmission() corrupting the contents of the GPIOR0 register

   *

   *  \section Sec_ChangeLog100219 Version 100219

   *

diff --git a/LUFA/ManPages/MigrationInformation.txt b/LUFA/ManPages/MigrationInformation.txt
index 262364070..8467e0019 100644
--- a/LUFA/ManPages/MigrationInformation.txt
+++ b/LUFA/ManPages/MigrationInformation.txt
@@ -12,8 +12,11 @@
  *

  * \section Sec_MigrationXXXXXX Migrating from 100219 to XXXXXX

  *

+ *  <b>Non-USB Library Components</b>

+ *    - The \ref TWI_StartTransmission() function now takes in a timeout period, expressed in milliseconds, within which the addressed

+ *      device must respond or the function will abort.

+ *

  * \section Sec_Migration100219 Migrating from 091223 to 100219

- *    - (None)

  *

  *  <b>Non-USB Library Components</b>

  *    - Due to some ADC channels not being identical to their ADC MUX selection masks for single-ended conversions on some AVR models,

diff --git a/Projects/TemperatureDataLogger/Lib/DS1307.c b/Projects/TemperatureDataLogger/Lib/DS1307.c
index 64e03df0d..0c1d98f00 100644
--- a/Projects/TemperatureDataLogger/Lib/DS1307.c
+++ b/Projects/TemperatureDataLogger/Lib/DS1307.c
@@ -21,7 +21,7 @@ void DS1307_SetDate(uint8_t Day, uint8_t Month, uint8_t Year)
 	CurrentRTCDate.Byte3.TenYear  = (Year / 10);

 	CurrentRTCDate.Byte3.Year     = (Year % 10);

 

-	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE))

+	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE, 10))

 	{

 		TWI_SendByte(DS1307_DATEREG_START);

 		TWI_SendByte(CurrentRTCDate.Byte1.IntVal);

@@ -48,7 +48,7 @@ void DS1307_SetTime(uint8_t Hour, uint8_t Minute, uint8_t Second)
 	CurrentRTCTime.Byte3.Hour    = (Hour % 10);

 	CurrentRTCTime.Byte3.TwelveHourMode = false;

 	

-	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE))

+	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE, 10))

 	{

 		TWI_SendByte(DS1307_TIMEREG_START);

 		TWI_SendByte(CurrentRTCTime.Byte1.IntVal);

@@ -68,7 +68,7 @@ void DS1307_GetDate(uint8_t* Day, uint8_t* Month, uint8_t* Year)
 	return;

 #endif

 

-	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE))

+	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE, 10))

 	{

 		TWI_SendByte(DS1307_DATEREG_START);

 		

@@ -77,7 +77,7 @@ void DS1307_GetDate(uint8_t* Day, uint8_t* Month, uint8_t* Year)
 

 	DS1307_DateRegs_t CurrentRTCDate;

 

-	if (TWI_StartTransmission(DS1307_ADDRESS_READ))

+	if (TWI_StartTransmission(DS1307_ADDRESS_READ, 10))

 	{

 		TWI_ReceiveByte(&CurrentRTCDate.Byte1.IntVal, false);

 		TWI_ReceiveByte(&CurrentRTCDate.Byte2.IntVal, false);

@@ -100,7 +100,7 @@ void DS1307_GetTime(uint8_t* Hour, uint8_t* Minute, uint8_t* Second)
 	return;

 #endif

 

-	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE))

+	if (TWI_StartTransmission(DS1307_ADDRESS_WRITE, 10))

 	{

 		TWI_SendByte(DS1307_TIMEREG_START);

 		

@@ -109,7 +109,7 @@ void DS1307_GetTime(uint8_t* Hour, uint8_t* Minute, uint8_t* Second)
 	

 	DS1307_TimeRegs_t CurrentRTCTime;

 

-	if (TWI_StartTransmission(DS1307_ADDRESS_READ))

+	if (TWI_StartTransmission(DS1307_ADDRESS_READ, 10))

 	{

 		TWI_ReceiveByte(&CurrentRTCTime.Byte1.IntVal, false);

 		TWI_ReceiveByte(&CurrentRTCTime.Byte2.IntVal, false);

diff --git a/Projects/TemperatureDataLogger/makefile b/Projects/TemperatureDataLogger/makefile
index 8fd2c2941..f48e155b0 100644
--- a/Projects/TemperatureDataLogger/makefile
+++ b/Projects/TemperatureDataLogger/makefile
@@ -193,7 +193,7 @@ CSTANDARD = -std=gnu99
 

 # Place -D or -U options here for C sources

 CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD) $(LUFA_OPTS)

-CDEFS += -DDUMMY_RTC

+#CDEFS += -DDUMMY_RTC

 

 

 # Place -D or -U options here for ASM sources