Merge pull request #55 from PsuFan/master

Turn off Interrupt Triggers and Pull Up Resistors on begin()

Author: ladyada

Adafruit_MCP23017.cpp

@@ -128,6 +128,14 @@ void Adafruit_MCP23017::begin(uint8_t addr, TwoWire *theWire) {
   // all inputs on port A and B
   writeRegister(MCP23017_IODIRA, 0xff);
   writeRegister(MCP23017_IODIRB, 0xff);
+
+  // Turn off interrupt triggers
+  writeRegister(MCP23017_GPINTENA, 0x00);
+  writeRegister(MCP23017_GPINTENB, 0x00);
+
+  // Turn off pull up resistors
+  writeRegister(MCP23017_GPPUA, 0x00);
+  writeRegister(MCP23017_GPPUB, 0x00);
 }
 
 /**

examples/interrupt/interrupt.ino

@@ -103,6 +103,11 @@ void cleanInterrupts(){
  * and you can wait for interrupts while waiting.
  */
 void loop(){
+  // Clear Previous Interrupts
+  if (digitalRead(arduinoIntPin) == LOW) {
+    mcp.digitalRead(0);
+    mcp.digitalRead(7);
+  }
 
   // enable interrupts before going to sleep/wait
   // And we setup a callback for the arduino INT handler.