Hi: Is it safe to call xQueuePeek inside an ISR function? Dennis

that is an easy question, the answer is no. Only functions with FromISR in their name can be called from an interrupt.

If I want to peek an item from an ISR function, how could I do it?

You might have good luck by starting with the xQueueReceiveFromISR code and modifying it appropriately.  I just looked at that code for the first time, so this suggestion may miss a subtle and important point, but if you leave out  "–( pxQueue->uxMessagesWaiting )" and the subsequent "if(){}else{}" block, you should be pretty close.