Peanut - Dietary Restriction Elephant

What is a dietary restriction elephant?

Peanut is a robotic companion for children with dietary restrictions that is capable of helping these children learn what they can and can’t eat. Peanut is currently capable of the following four dietary restriction modes:

Peanut Allergy

Lactose Intolerance

Gluten Intolerance

Vegetarian

Children interact with peanut by feeding him play food in order to create delicious and nutritious meals.

How Peanut Works

Peanut successfully interacts with children to inform them on correct food choices. This is how he does it.

The Brain

Peanut uses an Arduino Mega for all the processing that he does for reading in a food item and his response to that food. An Arduino was originally decided on due to the support surrounding it and its ability to interface with many of the components we added for actuation and sound. Other processors, for example a Raspberry Pi, would have also been an appropriate choice, but only has two PWM pins and we were not sure how many servo motors we wished to incorporate initially on the design. The Mega provided plenty of script space and many of the various types of pins that were needed to incorporate more features as there were more design iterations.

The Sensor

Every food item has a white, circular RFID tag that stores information based on the food allergy. When the tag is placed near the RFID reader, the two communicate using an electromagnetic field. The information is then forwarded to the Arduino through SPI communication. The Arduino uses the Mifare MFRC522 library, which made it easier to write information to the tags and to read the tags when one was in range of the card reader. The RFID reader is located in Peanut's mouth, so the children feel like they are feeding Peanut.

Actuation

Upon reading an RFID tag, Peanut will inform the user if he can or cannot eat the food by nodding his trunk up and down for yes or shaking his head no. This is done by two servo motors located in his head that sit inside a custom laser cut piece and are controlled through PWM.

Sound

Peanut also informs the child on a correct or incorrect food choice by speaking. Since the Arduino cannot store files, an Adafruit Sound Board stores the sound files and the Arduino communicates through software serial to indicate when and which file should be played. In order to hear the sound, there is a speaker attached to an amplifer. Peanut also informs the child what mode he's in when he first turns on and when the mode is changed.

Modes

Buttons are located on Peanut's stomach so he can change between modes. When the child hits the button, Peanut will inform him or her what mode he is now in by speaking. The child can then continue feeding Peanut.

The Making of Peanut

Peanut's first iteration includes an Arduino Mega, RFID reader, and two servo motors which are sewn into his head.

Only the two servo motors are currently inside Peanut. The RFID reader is fashioned into a necklace and the rest of the electronics are placed into a handmade backpack. Finally a handkerchief is tied around his neck to further hide the electronics backpack and to hide the wires coming from the RFID reader and servos.

Peanut is ready for his first testing day! Currently he only has one mode, a peanut allergy, and the RFID tags on the food have been programmed accordingly. When a child holds up a food item, Peanut will either nod his trunk or shake his head.

More components are added - sound and more modes. A zipper has been added so the electronics can easily be placed inside Peanut. The RFID reader is sewn into Peanut's mouth so the kids feel like they are feeding him.

The mess of electronics are packed into a box to easily place inside Peanut and remove when changes need to be made. Buttons are also added that will be sewn into Peanut's stomach so the user can change his mode without having to manually do it in the program.

Peanut is complete! All the electronics are inside Peanut, and he has a tongue to easily locate his mouth. View the Future section to see what needs to be improved.