Automated Coffee Machine

Group Members:Billy WhitehouseMatthew BittermanJamie Cochran

code.google.com/p/automated-coffee-machine/code.google.com/p/automated-coffee-machine/

Main Purpose

This is a SpecC implementation of a fully automated coffee machine. The main features include: built-in grinder, automatic water filler, auto-on clock, auto-off timer.

A creative component will investigate the use of Ethernet controller IP to add remote access to the coffee machine.

Project Status

Part A– Create Website: Completed– System Modeling: Completed– Refinement: Completed

Part B– Create SystemC Model: In-Progress– Creative Component: Completed

Top Level Diagram

Coffee Machine Components

Main Controller Clock Controller LCD Controller

Main Controller

The main controller contains:– The main state machine– The water flow control– The grinder control

Main Controller Chart

Main State Machine

Begin brewing when the “On” event is triggered in the clock controller

Initiate the brewing process (signals the grinder controller and water flow controller)

When the water flow and grinder are complete start the water heater

When the water heat process completes signal that the brewing is done (will start auto-off timer

Keep the coffee pot burner on until the “Off” event is triggered from the clock controller

Main State Machine Diagram

idle starting_brew

heat_water

heat_pot

finishing_brew

wait_water_grounds_done

Coffee Maker Main State Machine

auto_on

water_fill_done == 1&&

grinder_done == 1

water_level == 0

auto_off

reset

Water Flow and Grinder Control

The water flow controller uses the cups to brew and water level inputs to control the water flow mechanism. Once the water level equals the number of cups to brew the water flow mechanism is disabled.

The grinder uses the cups to brew, brew strength, and coffee grounds weight inputs to control the grinder. The formula to calculate coffee ground weight (in tenths of ounces) is as follows: cups_to_brew * 2 * brew_strengthwhere brew_strength is 1-weak, 2-regular, 3-strong

For example, to brew 6 cups at regular strength the amount of coffee grounds would be: 6*2*2 = 24 or 2.4oz (about 4.8 tablespoons)

Clock Controller

Handles all timing related functions– System Time (Clock)– Auto-On feature– Auto-Off safety feature

Triggers the LCD to update display information

Updating System Time

The main dial can be set to edit_time value to change the system time

When the update hour/minute event is triggered, the hour/minute is incremented with the minute being modulus 60 and hour modulus 24

Updating Auto-On Time

The main dial can be set to edit_auto_on value to change the auto-on time

When the update hour/minute event is triggered, the hour/minute is incremented with the minute being modulus 60 and hour modulus 24

Updating Auto-Off Time

The main dial can be se to edit_auto_off value to change the auto-off time

When the update minute event is triggered, the minute is incremented with the minute being modulus 60

When the update hour event is triggered the hour is incremented with the hour modulus 7 (this makes the auto-off time a maximum of 7 hours)

Clock Control Functionality

If the edit_time/auto_on/auto_off bit is asserted, go to the corresponding state and wait for the update_hour/minute signals to toggle

If the auto_on_en bit is set, go to the corresponding state and wait until system_time == auto_on_time

Once equivalent, notify auto_on

Clock Control Functionality (cont.)

Once in the run_state, wait until brew_done triggers or on_off deasserts

In the auto_off state, a down counter is loaded with the auto_off time in seconds shuts the machine off when the counter equals zero.

Return to the idle_state until more coffee is needed (approx. 30 min. for engineers)

Clock Control State Machine

LCD Control

Actual hardware would require an LCD display to present the 4 digit time. For the SpecC models we implemented a display driver which updates the terminal window with the user interface status.

Updates the display with the selected time (system time, auto-on time, or auto-off time)

Displays the selected cups to brew Displays the selected brew strength Displays the state of the coffee machine (brewing,

on, off)

Example Displays

Time: 12:30 PMSet Auto OnCups: 1Strength: RegularStatus LED: OffInput:hour 2

Time: 12:00 PM

Off

Cups: 1

Strength: Regular

Status LED: Off

Input:

Time: 12:13 PM

On

Cups: 12

Strength: Strong

Status LED: On

Brewing Status ------------- Grinder: On Water Flow: Off Water Heater: Off

Input:

Time: 12:16 PM

On

Cups: 12

Strength: Strong

Status LED: On

Brewing done. Warming coffee pot.

Input:main 4

Coffee Machine Testbench

The testbench has been created. It includes the models:

– grinder mechanism (coffee ground weight sensor)

– water flow mechanism (water level sensor)

– water heating mechanism– main dial control– cups dial control– strength dial control– hour/minute buttons

The testbench is controlled by commands in the terminal.

Outputs from the DUT control the mechanical testbench components which in turn report data from their sensors.

At the input prompt the valid commands are: main #

– 0: Set Clock – 1: Set Auto-On – 2: Set Auto-Off – 3: Off – 4: Auto-On Enabled – 5: On

cups # – 1-12

strength # – 1: Weak – 2: Regular – 3: Strong

hour # – will trigger the update_hour event the given # of times

minute # – Will trigger the update_minute event the given # of

times exit

– exit the simulation

Specification Model Connectivity

Specification Model Simulation

The specification model was simulated with stimulus that verifies the functionality of:

Setting the system clock, auto-on clock, and the auto-off time

Running with auto-on enabled

Waiting for auto-off time to be reached

Setting number of cups to brew and the brew strength

Initiating brew process with the On dial state

Turning off the machine with the Off dial state

Architectural Exploration

We chose to look at three processing elements for the architectural refinement:

Motorola 68HC12 Motorola DSP56600 Hardware Standard

Processing Element Allocation

Based on the computations, memory usage, and number of connections of each block we decided to allocate the HC12 processing element to the main controller block. The HC12 micro-controller is designed for automotive and home appliance electronics. This device will best fit the hardware needs for the main controller.

The clock controller and lcd controllers require much more processing power since they perform more computations and require much more memory. Therefore, the Motorola DSP56600 processing element will be allocated to those blocks.

Architectural Model

The behavioral and variable partitioning based on the architectural exploration resulted in the following architectural model

Waitfor statements were added to the SpecC behaviors to add computation timing.

Architectural Model Simulation

The architectural model was simulated with the same stimulus as the specification model.

The architectural model processing allocation looks like and design quality reports are shown below:

SystemC Model

A SystemC model will be created for the Automated Coffee Machine clock controller.

Creative Component

The Creative Component will investigate the use of Ethernet IP to add remote control to the automated coffee machine.

Requirements Provide a web interface which gives transparent access to the machine's controls The Ethernet IP must be able to communicate of the internet via the TCP/IP protocol with

at least 10Mbps (minimum speed since 100BASE-T is more the standard) data transfer rate

The packets will be decoded and the coffee machine commands will be extrapolated by the packet decoder. Such information includes:

– clock updating – coffee machine controls (cups to brew, strength, and main controls)

A packet encoder will generate packets to be sent across the internet to the remote user with the following information: Current time, auto-on time, auto-off time, cups to brew value, strength value, and current state.

Manufacturer provided MAC address

Ethernet Subcomponents

Ethernet Driver Ethernet Controller Packet Decoder Packet Generator

Ethernet Driver

The Ethernet driver is responsible for taking the data and transmitting it according to the Ethernet protocol. The means transmitting the data at the right frequency but also the bus voltage levels. The protocol would be handled between the Ethernet controller and the packet generator. The voltage levels for the bus could be integrated into the RJ-45 jack. If the right RJ-45 jack is included in the design, the transformers as well as transmit/receive or activity/link LED's are integrated and won't have to be designed into the circuit.

Ethernet Controller

The ethernet controller would be a specialized piece of hardware, such as Microchip's ENC28J60. There are many devices like this on the market with either a parallel or serial interface. They typically have an interrupt or wake-on-LAN (WOL) pin that alerts the microcontroller that activity has occurred. They also contain some on-chip memory for data coming or going out across the ethernet bus.

Packet Decoder

The packet decoding would have to be a very specialized behavior or module that would monitor the ethernet controller. Once the ethernet controller interrupted the packet decoder, it would read the data out of the buffer on the ethernet controller and decode the data packets and make the necessary changes to the coffee machine's setup. Since the ethernet controller would strip off all parts of the frame except the payload, the decoder would need to just parse the payload from the ethernet frame and write the new data to the variables.

Packet Generator

The packet generator is what would be running the web interface. This would send the sensor data or current setup to the user's web browser where they would be able to click buttons or make their selection to what they want the machine to do. Once the user clicks the submit button or something of the like, the data would get sent back to the ethernet controller which would then alert the packet decoder via interrupt or WOL. Since the current setup has very minimal variables, the payload would have to utilize data padding to meet the 46-byte minimum payload transmission specified by 802.3.

Tasks to Complete

Simulate the SystemC clock controller model.

Questions/Resources

Please email wdwhiteh@gmail.com with any questions

Visit the project webpage at:http://code.google.com/p/automated-coffee-machine/or through WebCT