diff --git a/io-helper.c b/io-helper.c
index d9e8fe1..25eb2e1 100644
--- a/io-helper.c
+++ b/io-helper.c
@@ -4,7 +4,20 @@
 volatile uint8_t outStates[]={0,0,0,0};
 volatile uint8_t inStatesRaw[] = {0,0,0,0};
 volatile uint8_t inStates[] = {0,0,0,0};
+
 volatile uint8_t oldInstates[] = {0,0,0,0};
+volatile uint8_t inStatesBothEdges[] = {0,0,0,0};
+volatile uint8_t inStatesRisingEdge[] = {0,0,0,0};
+volatile uint8_t inStatesFallingEdge[] = {0,0,0,0};
+
+void ioHelperEdgeDetector(void){
+    for (uint8_t i = 0; i < 4; i++){
+        inStatesBothEdges[i] = oldInstates[i] ^ inStates[i];
+        inStatesRisingEdge[i] = inStatesBothEdges[i] & inStates[i];
+        inStatesFallingEdge[i] = inStatesBothEdges[i] & oldInstates[i];
+        oldInstates[i] = inStates[i];
+    }
+}
 
 
 /* @brief: copies a single bit from one char to another char (or arrays thereof)
diff --git a/io-helper.h b/io-helper.h
index 779f8ae..8f9edc9 100644
--- a/io-helper.h
+++ b/io-helper.h
@@ -6,6 +6,10 @@
 extern volatile uint8_t outStates[4]; 
 extern volatile uint8_t inStates[4];
 extern volatile uint8_t ioHelperDebounceTable[32];
+extern volatile uint8_t oldInstates[4];
+extern volatile uint8_t inStatesBothEdges[4];
+extern volatile uint8_t inStatesRisingEdge[4];
+extern volatile uint8_t inStatesFallingEdge[4];
 
 void ioHelperSetOuts(void);
 void ioHelperReadPins(void);
@@ -13,7 +17,7 @@ void ioHelperIoConf(void);
 void ioHelperSetBit(volatile uint8_t *list, uint8_t nr, uint8_t state);
 unsigned char ioHelperReadBit(volatile uint8_t *list, uint8_t nr);
 void ioHelperDebounce(void);
-
+void ioHelperEdgeDetector(void);
 
 //Outputs
 //Pin | Bit in outStates