diff options
Diffstat (limited to 'LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.c')
| -rw-r--r-- | LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.c b/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.c new file mode 100644 index 000000000..6028bbae9 --- /dev/null +++ b/LUFA/Drivers/Peripheral/AVRU4U6U7/TWI.c @@ -0,0 +1,54 @@ +/*
+ Copyright (C) Dean Camera, 2010.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.fourwalledcubicle.com
+*/
+
+#include "TWI.h"
+
+bool TWI_StartTransmission(uint8_t SlaveAddress)
+{
+ for (;;)
+ {
+ uint8_t IterationsRemaining = 50;
+ bool BusCaptured = false;
+
+ while (IterationsRemaining-- && !BusCaptured)
+ {
+ TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN));
+ while (!(TWCR & (1 << TWINT)));
+
+ switch (TWSR & TW_STATUS_MASK)
+ {
+ case TW_START:
+ case TW_REP_START:
+ BusCaptured = true;
+ break;
+ case TW_MT_ARB_LOST:
+ continue;
+ default:
+ return false;
+ }
+ }
+
+ if (!(BusCaptured))
+ return false;
+
+ TWDR = SlaveAddress;
+ TWCR = ((1 << TWINT) | (1 << TWEN));
+ while (!(TWCR & (1 << TWINT)));
+
+ GPIOR0 = (TWSR & TW_STATUS_MASK);
+
+ switch (TWSR & TW_STATUS_MASK)
+ {
+ case TW_MT_SLA_ACK:
+ case TW_MR_SLA_ACK:
+ return true;
+ default:
+ TWI_StopTransmission();
+ break;
+ }
+ }
+}
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