Arduino Touchless Sanitizer Prototype

I’m putting together a compact, battery-powered hand-sanitizer station driven by an Arduino UNO. An ultrasonic sensor will sit at the front and, as soon as it senses a hand at roughly 5–10 cm, it should fire a solenoid or small DC pump mounted on a regular pump-top bottle. Everything must run reliably from batteries so the unit can be installed without mains wiring.

Here’s what I need from you:

• A clear wiring schematic that shows the UNO, the ultrasonic sensor, a transistor-driven pump circuit (with diode protection), power regulation, and a low-battery indicator.
• An Arduino sketch that lets me adjust distance threshold and dispense time from code constants, debounces false triggers, and sleeps between uses to conserve power.
• A concise bill of materials with exact part numbers for everything, including a suitable battery pack and switch.
• Brief assembly notes or photos so I can replicate your prototype without guesswork.
•if possible .. also add a battery level indicator

The build should work with inexpensive, widely available components; I’m in a hurry and don’t want to hunt for rare parts. If you’ve already built something similar, links or short clips proving stable pumping action will speed up selection.