Unusual, load-controlling barrier sensor

Using a cheap, widely used PIR Motion Module HC-SR501 sensor, you can make a barrier sensor that will control a load (one or two lamps or a fan, etc.) in a bipolar mode (when each subsequent sensor response switches the lamp to the opposite state). This is convenient because you do not need to constantly use the switches when moving from the hallway to the pantry or from the kitchen to the dining room, etc. At the same time, the movement of small children and pets will be ignored.
To make the sensor react to movement only in the desired zone, I used aluminum foil with a small hole in the center. This allowed me to greatly reduce the 110º angle of the sensor's field of view. The jumper in the sensor is set to position L, the timer is at minimum. Remember that it takes time to start the sensor after voltage is applied.
To control the output signal, I assembled a small circuit using a simple CD4013 chip. The second motion sensor (the top one in the diagram) is used here for contactless re