This is a device that makes and mixes different combinations of EANABs to make your favorite drink! You start by filling in your drink prefereces on our EANAB WebApp™ hosted on our Concierge™ and swiping your Stanford ID card to store your preferences in our database. Then, walk over to our DrinkMaker™ station and swipe your Stanford ID card to retrieve your preferences, which have been magically transmitted over Wi-Fi. Put a cup on top of the conveyor belt and press a blue button when you're ready to be breathalyzed. Our device is an EANAB maker that makes EANABs and EANABs only, so our breathalyzer will make sure you've only had EANABs today! Then, once the breathalyzer confirms you're good to go, the conveyor belt will move your cup to our valve station, where our specially configured valves will dispense the correct combination of components for your EANABs. Finally, our conveyor belt will return your drink to you, with a fresh cup of EANABs.
This is an online interface to enter in your preferences by first adjusting the amount of each ingredient you want through our draggable pie chart or adjusting the numbers, and then swiping your ID card to store your preferences.
Both our concierge and our maker use a PS/2 protocol magstripe to read your Stanford ID card to store and receive your drink preferences.
We use an ESP-32 on both the concierge and the maker to communicate drink preferences from one to another, so the maker can retrieve the appropriate drink when you swipe the card.
The fittingly-named TAJ (Theo, Ankush, Jainil) protocol is used to communicate preferences from the ESP32 to the Raspberry Pi. It's not just typical UART! We use our own modified protocol (based on PS/2) that can run over two aribitrary GPIO pins so that computer<->pi UART can run concurrently.
We use a pretty simple pull-up resistor and button to register when you're ready to be breathalyzed.
An arduino breathalyzer helps us make sure that you're good to drink our EANABs. We've calibrated the breathalyzer to get your BAC and reject you if you're over the legal limit of 0.08.
We use a stepper motor to drive our conveyor belt, with a pretty sick library of different angles, settings, directions, and things it can do.
How do we stop our conveyor belt? We use a photoresistor to register the presence of a laser that emits directly across from it; if the laser is blocked by a cup, the photoresistor tells the conveyor belt to stop moving and the program moves to drink filling.
We use an MCP3008 ADC to convert analog signals from the breathalyzer and the photoresistor to be used by the Raspberry Pi.
Our valves are solenoids that open when a 12V current is wired to them. We use a relay and GPIO pins to control when and for how long that current is present for, so that we can give you a nice drink with all of your desired components.
Our config didn't look cool enough as is, so we decided to give it some flair with some sick lighting.
Configure your development environment as specified here: http://cs107e.github.io/guides/mac_toolchain/
For the concierge: run 'make install-c'
For the maker: run 'make install-m'
Once both Pis are up and running, connect any external computer to the WiFi network "EANABMaker" to send in your drink preferences. Then, swipe your ID card to brew it up.
We worked on a lot of the project together, but to break down some of the responsibilities.
Theo: ESP32, TAJ protocol, magstripe, communication and storage of drink preferences
Ankush: valve control, breathalyzer control, rand library, construction
Jainil: stepper, photoresistor and laser, rand library, construction
We made this project for Stanford's computer systems class CS107E, and a lot of the code used in this project was made over the quarter when we started with barebones ARM assembly and slowly wrote higher level abstractions. Big thanks to our professors Pat Hanrahan and Julie Zelenski for being such awesome people and guiding us through this––and our incredible TAs too! <3
