diff --git a/IODevice.cpp b/IODevice.cpp
index 63a6d8b..b61ecf8 100644
--- a/IODevice.cpp
+++ b/IODevice.cpp
@@ -305,18 +305,16 @@ bool IODevice::owns(VPIN id) {
 // Minimal implementations of public HAL interface, to support Arduino pin I/O and nothing more.
 
 void IODevice::begin() { DIAG(F("NO HAL CONFIGURED!")); }
-bool IODevice::configure(VPIN pin, ConfigTypeEnum, int, int p[]) {
+bool IODevice::configure(VPIN pin, ConfigTypeEnum configType, int nParams, int p[]) {
+  if (configType!=CONFIGURE_INPUT || nParams!=1 || pin >= NUM_DIGITAL_PINS) return false;
   #ifdef DIAG_IO
   DIAG(F("Arduino _configurePullup Pin:%d Val:%d"), pin, p[0]);
   #endif
-  if (p[0]) {
-    pinMode(pin, INPUT_PULLUP);
-  } else {
-    pinMode(pin, INPUT);
-  }
+  pinMode(pin, p[0] ? INPUT_PULLUP : INPUT);
   return true;
 }
 void IODevice::write(VPIN vpin, int value) {
+  if (vpin >= NUM_DIGITAL_PINS) return;
   digitalWrite(vpin, value);
   pinMode(vpin, OUTPUT);
 }
@@ -324,6 +322,7 @@ void IODevice::writeAnalogue(VPIN, int, uint8_t, uint16_t) {}
 bool IODevice::isBusy(VPIN) { return false; }
 bool IODevice::hasCallback(VPIN) { return false; }
 int IODevice::read(VPIN vpin) { 
+  if (vpin >= NUM_DIGITAL_PINS) return 0;
   return !digitalRead(vpin);  // Return inverted state (5v=0, 0v=1)
 }
 int IODevice::readAnalogue(VPIN vpin) {