Commit c0c982df authored by Dean Camera's avatar Dean Camera
Browse files

Added a timeout value to the TWI_StartTransmission() function, within which...

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.
parent 14a5a940
......@@ -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)
......
......@@ -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;
}
}
}
}
......@@ -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
*
......
......@@ -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,
......
......@@ -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);
......
......@@ -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
......
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