diff --git a/I2CManager.cpp b/I2CManager.cpp
index 94c4baf..a3ea611 100644
--- a/I2CManager.cpp
+++ b/I2CManager.cpp
@@ -179,7 +179,7 @@ I2CManagerClass I2CManager = I2CManagerClass();
 /***************************************************************************
  *  Block waiting for request block to complete, and return completion status.
  *  Since such a loop could potentially last for ever if the RB status doesn't
- *  change, we set a high limit (0.1sec, 100ms) on the wait time and, if it
+ *  change, we set a high limit (1sec, 1000ms) on the wait time and, if it
  *  hasn't changed by that time we assume it's not going to, and just return
  *  a timeout status.  This means that CS will not lock up.
  ***************************************************************************/
@@ -187,8 +187,8 @@ uint8_t I2CRB::wait() {
   unsigned long waitStart = millis();
   do {
     I2CManager.loop();
-    // Rather than looping indefinitely, let's set a very high timeout (100ms).
-    if ((millis() - waitStart) > 100UL) { 
+    // Rather than looping indefinitely, let's set a very high timeout (1s).
+    if ((millis() - waitStart) > 1000UL) { 
       DIAG(F("I2C TIMEOUT I2C:x%x I2CRB:x%x"), i2cAddress, this);
       status = I2C_STATUS_TIMEOUT;
       // Note that, although the timeout is posted, the request may yet complete.
diff --git a/I2CManager_AVR.h b/I2CManager_AVR.h
index 310afa2..6492e00 100644
--- a/I2CManager_AVR.h
+++ b/I2CManager_AVR.h
@@ -62,7 +62,18 @@
  *  Set I2C clock speed register.
  ***************************************************************************/
 void I2CManagerClass::I2C_setClock(unsigned long i2cClockSpeed) {
-  TWBR = ((F_CPU / i2cClockSpeed) - 16) / 2;
+  unsigned long temp = ((F_CPU / i2cClockSpeed) - 16) / 2;
+  for (uint8_t preScaler = 0; preScaler<=3; preScaler++) {
+    if (temp <= 255) {
+      TWBR = temp;
+      TWSR = (TWSR & 0xfc) | preScaler;
+      return;
+    } else 
+      temp /= 4;
+  }
+  // Set slowest speed ~= 500 bits/sec
+  TWBR = 255;
+  TWSR |= 0x03;
 }
 
 /***************************************************************************