An example electronic device that includes a computing device further including a display and a housing. The housing has a front side and a back side, and the display is disposed on the front side. In addition, the electronic device includes a receptacle disposed on the back side of the housing. The receptacle is to receive an accessory device. Further, the electronic device includes a sensor in the receptacle to communicate with the computing device. The sensor to sense the presence of the accessory device within the receptacle. In response to the sensor sensing the presence of the accessory device within the receptacle, the computing device is to change a power state of the accessory device.