Group Members

• Eric Wong
• Reuben Juste
• Azim Ali
• Taylor Powell

Project Description

The goal of iCoffee is to have an automated coffee maker that could set the time and temperature of brew from the internet. Unfortunately, due to time constraints, we implemented a serial controlled system instead. Users can set the time to brew the coffee and the mBed Microcontroller will receive the information and act accordingly. iCoffee also features a range finder sensor that will detect if there is a cup to brew into.

Block Diagram

Parts Used

• mBed Microcontroller
• LV-MaxSonar - EZ1 High Performance Ultrasonic Range Finder
• Ethernet Interface
• Mr. Coffee DRX5 4-cup Programmable Coffee Maker
• JZC-11F Relay
• 2N3904 Transistor
• Diodes
• Wires

Hardware

Two digital out pins were tied to power transistors that each drive relays bridging across the push-buttons for on and off. Power transistors are needed as the mbed alone does not have enough current output to directly drive the relays with its digital output pins. The diodes bridging across the relay are for the reverse current that peaks when the relay is turned off. The relay circuit is as follows for both the on and off buttons:

Libraries

• http://developer.mbed.org/users/mbed_official/code/EthernetInterface/
• http://developer.mbed.org/users/donatien/code/NTPClient/

Source Code

Video Demo

Future Work

• Implement web based server to receive brew information via internet.
• Add a temperature sensor to control the temperature the user wants.
• Robotic arm that will pour coffee into individual cups.