Grocery Guard. Paul Santos. Senior Project Description. Western Washington University Electronics Engineering Technology

Transcription

1 Grocery Guard Senior Project Description Western Washington University Electronics Engineering Technology Paul Santos

2 Table of Contents 1) Introduction Page 2 2) Description & Sketch of Hardware Page 2 3) Functional Description Page 4 4) Development Plan Page 10 5) Electrical Specifications Page 11 6) Preliminary Parts List Page 11 Page 1

3 I. Introduction Grocery Guard is an integrated food saving solution designed to be used anywhere with a refrigerator. It has the ability to scan your items, store them in a digital database and be able to inform the user of when their items may expire. The main objective is to help people fight the problem of unnecessarily throwing out expired foods. The system uses a barcode scanner and a keyboard in order to input barcodes and expiration dates of the foods. With the use of a graphic LCD, the user then can look through the inventory and see what items they have and when they expire. II. Description & Sketch of Hardware The Grocery Guard system will be enclosed in a rectangular case that will be able to easily fit into a pre designed outlet in a fridge door or on a counter top. At a total depth of 50 mm, it will fit comfortably in any space. The contents of the box will include the microcontroller, a keyboard, barcode scanner, a rotary encoder, graphic LCD, PS/2 adapter and socket and 4 user interface buttons. A sketch can be seen in Figure 1 below. Additional sketches with dimensions can be seen in figures on the following page. Figure 1 Grocery Guard sketch Page 2

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5 III. Functional Description The Grocery Guard will utilize the Stellaris LM4F120 in order to control its functions. The block diagram shown in figure 3 illustrates all of the modules of the project and how they connect. Figure 3 Grocery Guard system block diagram Microcontroller This microprocessor has been selected due to its popularity in industry, product availability, and large memory capacity. The LM4F120H5QR Stellaris chip is a 32 bit ARM M4F based microcontroller with 256 KB Flash memory, 32 KB SRAM and 2KB of EEPROM with 80 MHz operation frequency. Power Supply The system will be powered by a 5 volt supply that is taken from a wall wart or power supply in the lab for development purposes. In the technical demo, the 5v will be taken from a 5v bus line that is located in the refrigerator. If the specific fridge used for demoing does not have a 5v line then the device will be powered through a 5v wall ac/dc adapter. Graphic LCD A graphic LCD has been chosen for this project because of its ability to produce varying text sizes and its capacity for displaying large amounts of text thus being more visually appealing to the user. The LCD will be used to display the main menu, functions for the buttons, and the list of items the user currently has in their grocery inventory. Page 4

6 Keyboard A full keyboard is required for this project. This was decided based on the potential condition of when there is no barcode to scan; the user will have to then enter the description of the item themselves as well as the expiration date. Specifically, a PS/2 connection mini keyboard was chosen for the ease of interfacing with the microcontroller as well as for the size requirements of the Grocery Guard System. Barcode Scanner For this project the barcode scanner will be used to scan barcodes of the user s groceries in order to speed up the adding of items into the inventory database. A Unitech MS 210 PG provides a reliable, low cost barcode reader suitable for house hold applications. Most importantly, it comes supported with a keyboard wedge interface which can be interjected between the keyboard and the PS/2 socket wired to the microcontroller. With this interface, the barcode scanner can act like a keyboard that will quickly transmit a string of numbers to the microprocessor. Buttons The four buttons chosen for this project will be used to navigate the various states and menus in the Grocery Guard system. The actions of the buttons will change depending of which state they are in. So in order to see what action each button will produce, the action will be displayed above each button on the LCD screen. The buttons will be simple tactile on/off momentary push buttons. These buttons will also need to have debouncing code written in order for them to not pre maturely activate states. Rotary Encoder A rotary encoder will be used mostly to scroll through the inventory database that the user will eventually populate. The encoder will be a mechanical encoder with detent so the user can feel each scroll making it more user friendly. Software The Grocery Guard software will be written in C using Code Composer Studio. The main program will control the user interface, handling the user input data, and output the inventory list to the LCD. Pressing the appropriate buttons will move the program to the next or previous menu. When viewing the inventory, the user can rotate clockwise or counter clockwise on the encoder to scroll up or down respectively. When adding an item the user will be able to either use the keyboard or barcode scanner in order to type in the appropriate UPC or the user can press a button to add an item by name. When the user is removing an item they can either scroll through the inventory by use of the encoder or scanning an item to select an item to delete from the inventory. In order to keep an accurate real time clock, a real time slice kernel will be used. User Interface When booted, the program will sit at the system setup menu waiting for the user to enter a time and date. Once this has been entered, the program will move to the main menu that can be seen in figure 4. From the main menu, there are four actions the user can choose from. The first option is pressing button 1 which will direct the user to the inventory screen. The second option is pressing button 2 which will allow the user to be able to remove an item from the inventory. The third option is Page 5

7 pressing button 3 which will add an item that doesn t have a barcode. The last option is to enter the Universal Product Code (UPC) number by either scanning the UPC on the item or by entering it by hand on the keyboard. Another option is shown for button 4 but it may or may not be implemented in this project due to time restraints. B2 B4 Figure 4 Main Menu screen When viewing the inventory, the user can use the scroll wheel (the rotary encoder) to scroll up and down through the inventory list. An example of the inventory screen can be seen in figure 5. Once the user is done looking through the list, they can press button 1 again to go back to the main menu. B2 B4 Figure 5 Viewing Inventory screen When removing an item, the user will be prompted to either enter a UPC or manually search the inventory to remove the item. The user also has an option to exit to the main menu at any time. All of these options can be seen in figure 6.1 on the following page. Page 6

8 B2 B4 Figure 6.1 Removing an item screen Once an item has been selected, the user will be moved to a confirmation screen that will ask if they are sure if they want to delete the item. The user can exit to the main menu without saving any changes, say no and go back to choosing an item to remove or confirm the deletion as shown in figure 6.2. B2 B4 Figure 6.2 Confirmation of removal screen When adding an item, the user has the option of either entering the name of the item or entering the UPC number. When adding a product by name, the user will enter the name of the item as seen in figure 7.1 on the following page. Page 7

9 B2 B4 Figure 7.1 Enter name screen Once entered, the program will move to prompt the user for an expiration date as seen in figure 7.2. The user can enter the expiration date of the item via the keyboard then press enter. If an expiration date is not available, the user then will enter 0 or N/A. Also the user can at anytime cancel the adding process and exit to the main menu. B2 B4 Figure 7.2 Entering expiration date screen If the user decides to scan or enter a UPC number from the main menu, the program will go to an error/ database check state. This state will check to see if the user actually entered a UPC number (i.e. correct length for a UPC number) and whether it matches anything in the database. If it matches something in the database it will continue to the enter expiration date state mentioned above. If there is a problem with the input or a match was not found, the user will be prompted to either enter the UPC again by keyboard or barcode scanner which will return to the error/ database check state. However, if the user decides to add the UPC number to the database they will be moved to the enter name state. An example of this menu can be seen in figure 7.3. Page 8

10 B2 B4 Figure 7.3 Error/ UPC not found screen A sketch of the user interface can be seen in Figure 4 7 and the state diagram of the user interface can be seen on the next page in Figure 8. Reset Button 1 = Button 2 = B2 Button 3 = Keboard/Barcode scanner input = KB Scroll Clockwise = S1 Scroll Counter Clockwise = S2 S1 S2 Search Inv Confirm KB B2 Remove Item B2 System Setup Main Menu View Inventory S1 S2 KB Enter Expiration Date Good Error/ Database check Bad Invalid format or not in database Enter name of item Figure 8 State Diagram of the User Interface Page 9

11 Sustainability To address the increasing importance and demand of environmental impact and power consumption, this system will spend most of its life cycle in a hibernation mode and be only assembled using RoHS compliant parts. Also due to the nature of this system, it is believe that if used properly, it will be able to reduce the food and energy loss associated with throwing away expired food. IV. Development Plan This project is split in to two main sections. The first stage is the planning stage to where the project will be planned out to what may be needed and a rough timeline is completed. The second stage is the research phase which will take more time to concretely pin down what materials exactly are needed. The majority of the project will be spent during Hardware and Software Implementation. During this time the display, barcode scanner, keyboard and the software will all be worked on and combined together into a working prototype. A visual representation of the timeline can be seen below in table 1. Date Tasks # 12/31/12 1 Order any remaining parts 01/07/13 2 Get Familiar with Stellaris architecture 01/14/13 3 Research and Develop code to interface with LCD 01/21/13 4 Research and Develop code to interface with LCD 01/28/13 5 Research and wire PS/2 connections to MCU 02/04/13 6 Develop code to take inputs from PS/2 Keyboard 02/11/13 7 Develop code to take inputs from PS/2 Keyboard 02/18/13 8 Test PS/2 interface with barcode scanner 02/25/13 9 Assemble and test buttons and rotary encoder 03/04/13 10 Get real time clock to display to LCD 03/11/13 11 Finals 03/18/13 Spring Break 03/25/13 1 Program viewing inventory 04/01/13 2 Program viewing inventory 04/08/13 3 Program adding items to inventory 04/15/13 4 Program adding items to inventory 04/22/13 5 Program removing items from inventory 04/29/13 6 Program removing items from inventory 05/06/13 7 Make PCB and build case for Grocery Guard 05/13/13 8 Test and review all hardware and software 05/20/13 9 Code Review 05/27/13 10 Final Test and build 06/03/13 11 Finals/Demo Table 1 Grocery Guard Development Schedule Page 10

12 Demonstration In order to properly demonstrate the Grocery Guard system, a demonstration box that can be mounted onto a mini fridge will be constructed. This case will be built out of a preexisting case that will be cut and sanded to fit all of the components included in the project. It will be powered with a wall connection wall wart, and be ready sitting at the main menu. A small assortment of items will be placed next to the display in order for users to interact with adding items via the keyboard or barcode scanner. V. Electrical Specifications Operating Temperature: 5 V Supply 5 v Stellaris LM4F120 XL 21.6 mw(max) Keyboard 42.5 mw(max) Barcode Scanner 575 mw(max) Rotary Encoder 50 mw(max) Graphic LCD 165 mw(max) Worst case power dissipation mw(max) Table 2 Electrical Specifications VI. Preliminary Parts List Part # Description Price Qty Price Distributor Lead Time EK LM4F120XL Stellaris Micro Controller $ $ 4.99 Texas Instruments 1 GDM12864H Graphic LCD 128x64 $ $ Adafruit 1 PS/2 and USB $ $ Adafruit 1 Keyboard PS/2 Wired Connector $ $ 3.95 Adafruit 1 Rotary Encoder $ $ 1.40 DigiKey 1 Unitech MS210 1 Barcode Scanner $ $ Ebay 1 Push Button $ $ 3.12 Digikey 1 Power Dissipation 21.6 mw 165 mw 42.5 mw 50 mw 575 mw Total $ Table 3 Preliminary Parts List Page 11