Today it seems that we’re making more of an effort than ever before to keep our hands clean. However, sinks and even hand sanitizer kiosks, generally suffer from the fact that they must be installed at one height. While this is great if you’re the average person, if you’ve very tall or very short, this can be inconvenient. The problem is exacerbated with children, whose heights can vary greatly, and may need help anyway.
To combat this problem, Jegatheesan Soundarapandian came up with a portable auto-height adjust stand. The system takes the form of a PVC pipe frame, to which is mounted a stepper motor, CNC driver, and Arduino Uno for control. When someone steps into position below its HC-SR04 ultrasonic sensor, the stepper moves a stand up or down, by rolling up or letting out string that supports the platform vertically.
In addition, Soundarapandian also outlines plans for an Arduino-less hand sanitizer dispenser in his write-up. This utilizes an IR sensor module and a relay to trigger the pump motor, and features a rechargeable 18650 battery that allows it to be implemented anywhere. Whether you're short or tall, these two elements, plus actual hand sanitizer, should provide all you need to keep your hands – and the hands of others – properly sanitized!