parking is a condition when you leave your vehicle temporarily in a place, whether is a parking space or just a space. at this moment in a big city, looking for a parking space is getting harder because there is a lot of vehicles in town. with this device the parking space will automatically stop open the portal when there is no more space in the parking area.
to gather all parking space data it's need ultrasonic sensors hc-sr04 in every parking space. so if there are 20 parking space it needs 20 ultrasonic sensors and sent all the data to wemos d1 mini.