Sensor arrangements for determining the position of a firing element in an end effector of a surgical instrument. In various forms, the sensor arrangement comprises a resistive element supported in the end effector. As the firing element translates within the end effector, it movingly contacts the resistive element to generate signals indicative of the firing element position. In other arrangements, the sensor can detect the status or presence of a staple cartridge in the end effector. The sensor arrangement can communicate with a memory device, processor and indicator.