diff options
Diffstat (limited to 'LUFA/Drivers/Peripheral/TWI.c')
| -rw-r--r-- | LUFA/Drivers/Peripheral/TWI.c | 61 |
1 files changed, 40 insertions, 21 deletions
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;
- }
+ }
}
}
|