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A Food Delivery Box with AudioSerial Modem Lock

Prototype for the AudioSerial Lock

AudioSerial Over the Air!

Jan 22, 2021

in: android, covid19

Robots Everywhere has once again partnered with Tarlow Design to help food deliveries reach their clients securely and safely, in the wake of COVID-19. We hope with the use of our technology, we can overcome some common problems small restaurants have with big delivery services. More interestingly, we've found a way to expand our AudioSerial technology to operate over the air - not just over the wire!

Mr. Tarlow’s client came to us with an interesting problem: use surplus Android phones, and your AudioSerial technology, to make a food delivery box that the intended recipient can unlock with their own phone. We wanted to avoid any pairing, peering, or otherwise making the two phones identify each other, so we looked at alternative means. Because we have some experience in alternative audio communications we thought “why not use AudioSerial both ways?”. AudioSerial to have the phone talk to the lock controller, and a variation of AudioSerial to have the recipient’s phone play an audio tone to unlock the box.

The process of using this locking mechanism is relatively simple. With the system unlocked, set the locking code using the Android app and the touchscreen, and lock the system. Then, from the terminal app, send the unlock code to the customer over SMS. This will give them a message with a clickable link. Then, wait for the box to be delivered to the customer - we recommend using one of our robots; for small businesses on a budget, our surplus truckbots is a great option. For other options, Contact Us.

Once the robot, or human, has completed the delivery, the customer can click the link on their personal phone, playing the audio tone. This is where the magic happens: the phone on the box will perform DTMF detection, decoding the DTMF signal into bytes, and transmitting it to the locking board as serial data, opening the box. While it is a relatively simplified means of transmitting serial data over the air, it allows for simple devices like this to be opened without physical contact, which has advantages such as when trying to avoid transmission of disease.