Presentation of Scale Design

 

Overview of Approach

 

The scale interface for ScalePlus is designed for a 320x240 resolution LCD with 8 buttons for user input. To the left of the LCD are the Menu, Read, and Help buttons. The Menu button brings up the menu for all of the users’ and administrator’s tasks. The Read button reads the screen again in case the user missed something the first time. The Help button brings up a guide for interacting and using the current screen shown on the LCD. The B1 – B5 buttons at the bottom side of the LCD are used for data entry, selection and navigation in the context of the current screen being displayed. Though the functionalities of the B buttons change from screen to screen, it is important to give them names for the purposes of identification, documentation and guidance in the help screens and tutorials.

 

For the frequent task of taking weight readings, users do not have to press any button. Upon stepping on the scale registered users are automatically recognized and the readings are automatically recorded. The display highlights 2 pieces of important data – current weight and body fat. Because of the relatively large fonts those are easily seen at a distance of 4-6 feet. The next most useful data are the weight gain/lost statistics. Those are also highlighted but the font is not as large as the fonts for current weight and body fat. For infrequent tasks that involve going into the menu the text fonts on the 320x240 resolution LCD are viewable at 3-4 feet distance. Those tasks also involve button presses. Although some easy tasks could be done using the voice readout feature and using toes to press on the buttons, those tasks are meant to be done by hand. For maximum flexibility the actual build of ScalePlus should allow the option of detaching the interface panel for mounting it on the wall at eye level.

 

 

Transition Diagram

 

Figure 1: Scale interface transition diagram

 

 

Screenshots

 

Below are the key screens of the design. These figures have been scaled at 73% of the size of the actual screenshots.

 

Figure 2: A registered user on ScalePlus

 

 

This screen is what people see when the scale is turned on.  This is what people spend most of their time looking at when using the scale.

 

The LCD shows the current reading in large font size in the upper half of the screen.  To the right is the calculated body fat.  The bottom half shows the users’ registered name and also their most recent reading (if any).  The right-most column shows changes comparing to the current reading.  The main purpose is having the most recent reading displayed onscreen so users would know if they have gained or lost weight right away without having to remember what it was or spend extra time going into data review mode.

 

View the Help screen.

Figure 3: ScalePlus with no one on it

 

 

This is what the LCD looks like when ScalePlus is turned on and no one is standing on it or when users have stepped off the scale.

 

View the Help screen.

Figure 4: An unrecognized user on the scale

 

 

For an unrecognized user, the system does not show a name and the history. The user status is shown as “unknown” and the reading is not recorded in memory. Note that “unknown” is not a user account.  In this case ScalePlus behaves just like a typical bathroom scale.

 

View the Help screen.

Figure 5: Simulation of body measurements

 

 

Data retrieved from this form are used solely

to simulate the scale's job of measuring the weight

and calculating the body fat of the person standing

on the scale

 

For the prototype, feed in the following data:

·        User detected as - select one of the currently registered users, or select "unknown" to indicate an unrecognized user.

·        Date - select an incrementing date/time and pretend that this is a real time clock.

·        Weight – the weight that any real scale could measure.

·        Fat - the body fat measurement.

 

View the Help screen.

 

Figure 6: The menu

 

 

The menu allows access to the extra functionalities which the ScalePlus offers.  It is accessible by pressing the Menu button on the scale at any time.  Menu traversal and item selections are triggered by pressing the indicated B buttons.  The advantage to this design is that item selections are accomplished by one button.  The system does not use numeric values on menu item listings because sometimes menus/sub-menus expand multiple screens, therefore repetitions of numeric values could become confusing to the user.  To avoid confusion, menu items carry the full button codes (i.e B1, B2, B3 as opposed to 1, 2, 3).  The one-button-selection scheme and the labeling using full button codes go perfectly with the screen reader (voice readout feature).  The scale would read out the button name and the corresponding item or action.  The user then presses that one button and completes the selection process.

 

View the Help screen.

 

Figure 7: User Selection

 

 

Choosing “Review User Data” or “Edit User Profile” requires users to log in.  This screen asks users to select their name from the list of registered users.

 

Users can cancel the whole process by pressing the Cancel button (B3).

 

To scroll through the list press the up and down arrows (B1 and B2).  To confirm the selection users would then press Select (B4).

 

View the Help screen.

Figure 8: User Authentication

 

 

Upon selecting a user, ScalePlus asks to key in the password code for the requested user.

 

The user could cancel the whole process by pressing the Cancel button (B4).

 

The password is a 4 digit code.  The cursor indicates the current digit to enter.  To move the cursor left or right, press B1 or B2, respectively.  To select a value for the current digit, the user scrolls through the list by pressing “ABC..” (B3).  When users pressed “confirm” (B5) the system validates the password and either rejects the password or proceeds onto Data Review or Profile Edit.

 

View the Help screen.

Figure 9: Data Review

 

 

Upon keying in the correct code the users see a listing of their previous readings, sorted on date starting from the most recent reading.  The list is scrollable using the B1 and B2 function buttons.  When done viewing the users would press Done (B5) to come back to the Menu screen.

 

A great function to add to DataReview is the ability to sort the entries by weight.  The buttons on the screen design was fixed up to account for the feature, though not actually implemented.

 

View the Help screen.

Figure 10: Profile Edit

 

 

This is where users can change their profile settings and preferences.  Weight unit and voice readout are also manipulated by the administrator/scale owner’s system settings.  If the system setting for voice read out is ON but users do not like having their screens read out, they may choose to turn it off.  Likewise, if the system setting for weight unit is kg but users want to switch to pound, they may change it for their profiles.

 

This screen also allows users to change their passwords to prevent people from viewing their profiles and recorded readings.

 

View the Help screen.

 

 

Figure 11: The scale setup screen

 

 

The Setup screen contains administrative tasks designed to give the owner of the scale control over system and networking settings and also the ability to add/remove users.

 

Setup spans over 2 screens.  Upon pressing the down arrow (B5) the system brings up the second setup screen with more system settings and options.

 

View the Help screen.

Figure 12: Setup screen #2

 

 

This setup screen allows the administrator to specify voice read out and weight unit preferences.

 

Pressing B1 would toggle voice read out ON and OFF. When it is in the ON state, users could specify their own sound setting (ie. keep it as ON, or set it to OFF).

When it is in the OFF state, ScalePlus would not read the screen even if the users turn it on in their profile preferences.

 

Pressing B2 would toggle the weight unit between pounds and kilograms.  This would be used as the default unit for all users.  Users could choose their own unit in their profile preferences.

 

Pressing B5 would bring up the first setup screen.

 

View the Help screen.

Figure 13: The administrator adds a new user

 

 

The scale interface does not enough have buttons for quick data entry.  So data are entered character by character using the B buttons.

 

To select a character for a slot, press the left & right arrows to move the cursor to the desired slot.  Then press “ABC..” (B3) to scroll through a list of valid characters.  The first 10 character slots (top line) are for the name field and the next 4 slots (bottom line) are for the height field.  When done, press Add (B5) to create a new profile under the desired username.

 

To abort the operation press Cancel (B4).

 

View the Help screen.

Figure 14: The administrator removes a user

 

 

This screen asks the administrator to select a name from the list of registered users to remove it from memory.

 

The admin scrolls through the list by pressing the up and down arrows (B1 and B2).  To confirm the selection the admin would then press Remove (B4).

 

To abort the operation press Cancel (B3).

 

View the Help screen.


 

 

Tutorial

 

§         Getting help on a screen

On any screen, press the Help button for instant help and more detailed explanation on the screen.

 

§         Taking a measurement.

1. At the standard screen (Measurement) mimic the act of stepping on this virtual scale by pressing “Simulate user stepping on ScalePlus”. 

2. A dialog pops up. Fill out the form and press Submit. (See “Simulate user stepping on ScalePlus” for more info)

3. When done, press “Step off ScalePlus”

 

ScalePlus does not require users to be registered.  However, users who are not registered (aka “unknown”) do not have the benefit of storing and viewing records of their readings.  To such users, ScalePlus is no more special than the regular scale.

 

See “Registering a new user” to learn how to add a new user on ScalePlus.

 

§         Simulate user stepping on ScalePlus.

1. Fill out all four fields:

User detected as - select one of the registered users, or select "unknown" to indicate an unrecognized/undetected user.

Date - select a date/time and pretend that this is a real time clock. Thus it only makes sense to choose an incrementing date every time you pick a date.

Weight - feed in a weight

Fat - feed in the body fat (in percentage) measurement and pretend this is the scale's actual calculated value.

2. Press Submit to feed the above info into the virtual scale

 

§         Registering a new user.

1. Press the Menu button to bring up the menu screen.

2. Press the B3 button for “Setup”

3. Press the B1 button for “Add new user”

4. Fill out the name and height

*Note that these are not implemented yet.  The system already filled out the fields for the username Bob.

-Press the left & right arrows (B1 & B2) for cursor movement

-Press “ABC..” (B3) for character selection at the current cursor

5. Press B5 for “add”

 

§         Removing an existing user.

1. Press the Menu button to bring up the menu screen.

2. Press the B3 button for “Setup”

3. Press the B2 button for “Remove user”

4. Press the up & down arrows (B1 & B2) to scroll through the list of registered users

5. Press B4 for “remove”

 

§         Turning voice-readout On/Off.

            Global setting (for administrator)

1. Press the Menu button to bring up the menu screen.

2. Press the B3 button for “Setup”

3. Press the B5 to bring up more setup options

4. Press B1 to toggle voice-readout On/Off

5. When done, press B4 to exit Setup.

6. Press B4 to exit Menu

 

Individual setting

1. Press the Menu button to bring up the menu screen.

2. Press the B2 button for “Edit User Profile”

3. Select your user name. (See “User Select Screen”)

4. Key in your password. (See “Password Screen”)

5. Press B1 to toggle voice-readout On/Off

6. When done, press B4 to exit.

7. Press B4 to exit Menu

 

§         Specifying weight unit (pound or kilogram).

            Global setting (for administrator)

1. Press the Menu button to bring up the menu screen.

2. Press the B3 button for “Setup”

3. Press the B5 to bring up more setup options

4. Press B2 to toggle between “lb” and “kg”

5. When done, press B4 to exit Setup.

6. Press B4 to exit Menu

 

Individual setting

1. Press the Menu button to bring up the menu screen.

2. Press the B2 button for “Edit User Profile”

3. Select your user name. (See “User Select Screen”)

4. Key in your password. (See “Password Screen”)

5. Press B2 to toggle between “lb” and “kg”

6. When done, press B4 to exit.

7. Press B4 to exit Menu

 

§         User Select Screen

This screen is used in the process of logging in a user for data reviewing and for profile editing

 

- Press the up and down arrows (B1 & B2) to scroll through the list of users

- Press “select” (B4) to confirm the selection

- Press “cancel” (B3) to abort the operation

 

§         Password Screen

This screen is used in the process of logging in a user for data viewing and for profile editing.

 

- Press the left & right arrows (B1 & B2) for cursor movement *

- Press “ABC..” (B3) for character selection at the current cursor *

- Press “confirm” (B5) to confirm the selection.

- Press “cancel” (B4) to abort the operation at any time.

 

Note that password entry is not implemented yet. All four password digits are already filled out.  So only need to press B4 to confirm.

 

§         Viewing user recorded readings.

1. Press the Menu button to bring up the menu screen.

2. Press the B1 button for “Review User Data”

3. Select your user name. (See “User Select Screen”)

4. Key in your password. (See “Password Screen”)

5. Press the up and down arrows (B1 & B2) to scroll up and down the table.

6. When finished viewing, press “done” (B3) to go back to Menu

7. Press B4 to exit Menu

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