A control unit includes a non-volatile memory and a CPU. The non-volatile memory stores activation interval information indicating an activation interval of mixed processing of transmission processing and non-transmission processing. The transmission processing executes a signal transmission through a bus and the non-transmission processing executes no signal transmission through the bus. The CPU determines an execution start time of the mixed processing based on the activation interval information stored in the non-volatile memory and executes the mixed processing from a determined execution start time. An interval of execution of the signal transmission processing executed in the mixed processing by changing the activation interval information stored in the non-volatile memory. It is thus possible to protect wireless communication from interference by changing the activation interval of the mixed processing so that a frequency determined in correspondence to the activation interval of the mixed processing does not match a frequency of a communication channel of the wireless communication.