implement Wire.end() for AVR core

2 files changed, 17 insertions, 0 deletions

diff --git a/libraries/Wire/utility/twi.c b/libraries/Wire/utility/twi.c
index 201d7d1..d7d72bc 100644
--- a/libraries/Wire/utility/twi.c
+++ b/libraries/Wire/utility/twi.c
@@ -91,6 +91,22 @@ void twi_init(void)
 }
 
 /* 
+ * Function twi_disable
+ * Desc     disables twi pins
+ * Input    none
+ * Output   none
+ */
+void twi_disable(void)
+{
+  // disable twi module, acks, and twi interrupt
+  TWCR &= ~(_BV(TWEN) | _BV(TWIE) | _BV(TWEA));
+
+  // deactivate internal pullups for twi.
+  digitalWrite(SDA, 0);
+  digitalWrite(SCL, 0);
+}
+
+/* 
  * Function twi_slaveInit
  * Desc     sets slave address and enables interrupt
  * Input    none
diff --git a/libraries/Wire/utility/twi.h b/libraries/Wire/utility/twi.h
index 6526593..4c52bc5 100644
--- a/libraries/Wire/utility/twi.h
+++ b/libraries/Wire/utility/twi.h
@@ -39,6 +39,7 @@
   #define TWI_STX   4
   
   void twi_init(void);
+  void twi_disable(void);
   void twi_setAddress(uint8_t);
   uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t, uint8_t);
   uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t, uint8_t);