Deliver me through Covid

Motivation

When people must be in quarantine, whether at home or in hotel quarantine (as mandated by many countries), they still need supplies, which must be delivered in a completely non-contact way.

People in quarantine are advised to wait at least 20 seconds between a knock on the door and opening it to allow the delivery person to move away from the area. This does not always happen when you are hungry and you know that there is hot food outside your door!

Solution

We need a touch-free, time-delay doorbell. It is activated by a simple wave of the hand, and the time delay ensures the delivery person can move well away before chiming. If visitor entry is required (e.g. health care worker), there is an option to avoid the delay and chime the doorbell immediately.

Using the doorbell

Mount the sensor box (containing the arduino and battery) on the outside your door. The speaker box is mounted inside.

For deliveries, leave item(s) near door and wave hand slowly in front of sensor in a left-right-left motion until the yellow light turns on and then depart. After 20s, the doorbell will play a short melody.

For immediate entry, wave hand in front of the sensor in an up-down motion until the doorbell chimes.

The Build

This fairly simple circuit can easily be built on a breadboard, but for robustness I soldered it using a matrix board (we don't want things falling apart if the door slams). To save space I mounted the components in the space underneath the arduino.

Use about 1m of speaker wire between the 2 boxes. Solder the capacitor near the speaker terminals for better sound quality.

Here is how it looks before putting everything into their boxes.

Select 2 small boxes to mount everything inside. You'll need to make holes:

• In front of the gesture sensor

• In front of the yellow LED

• For cable routing

• To allow the sound to come out

Connect the battery, run the speaker cable over the top of the door and mount both boxes in place using double sided tape. I used a label printer to make some instructions which I attached to the sensor box, but a small card beside the unit works too.

Finally, it's time to put the doorbell to use - start ordering parts for your next project!