Adding shiftIn() from Wiring (no count or delaytime though).

2 files changed, 19 insertions, 3 deletions

diff --git a/cores/arduino/wiring.h b/cores/arduino/wiring.h
index d0ce1c3..6f61293 100755
--- a/cores/arduino/wiring.h
+++ b/cores/arduino/wiring.h
@@ -117,7 +117,8 @@ void delay(unsigned long);
 void delayMicroseconds(unsigned int us);
 unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout);
 
-void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, byte val);
+void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val);
+uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder);
 
 void attachInterrupt(uint8_t, void (*)(void), int mode);
 void detachInterrupt(uint8_t);
diff --git a/cores/arduino/wiring_shift.c b/cores/arduino/wiring_shift.c
index 956f864..cfe7867 100755
--- a/cores/arduino/wiring_shift.c
+++ b/cores/arduino/wiring_shift.c
@@ -24,9 +24,24 @@
 
 #include "wiring_private.h"
 
-void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, byte val)
+uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) {
+	uint8_t value = 0;
+	uint8_t i;
+
+	for (i = 0; i < 8; ++i) {
+		digitalWrite(clockPin, HIGH);
+		if (bitOrder == LSBFIRST)
+			value |= digitalRead(dataPin) << i;
+		else
+			value |= digitalRead(dataPin) << (7 - i);
+		digitalWrite(clockPin, LOW);
+	}
+	return value;
+}
+
+void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
 {
-	int i;
+	uint8_t i;
 
 	for (i = 0; i < 8; i++)  {
 		if (bitOrder == LSBFIRST)