Specifications

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They will be using a serial LCD made by Monochrome in our design. Some of the many
advantages of this LCD display is that it uses an onboard PIC tells the display to show
alphanumerical characters rather than printing to a seven segment display. It also uses
very low power which will be essential to this design since they are looking to optimize
energy stored in a battery. Some of the features that they will be using with this LCD is
the brightness display as well as the on/off feature. It also uses very low power and
features can be turned on and off where they see fit. This LCD display can store up to
80 characters on one single display. The backlight can handle up to 1 A current to light
the screen. It can be assumed that this will be at maximum brightness. It will also have
a splash screen, which will show some kind of logo, or lettering that we plan on
branding our design. In our design we will incorporate a 40% brightness. The less
power we use on the backlit screen we can save to run other features or save power
overall. The screen will be powered by a 5 volt serial connection connected to a
MSP430 which will be used to monitor the system. On the screen we will show items
that include but not limited to: Power consumption, Charge left in battery, time until
shutdown, recharge rate compared to discharge rate in percent.
The LCD screen will display to the user information about the system as well as
information of perceived events if the current usage/charging keeps up. It will display
the message "Power Consumption: XXXXX Watts" where XXXXX is the total power
usage at that particular moment. We will also be using buttons some of them will be
intended to save more power by turning off the display as well as turning it back on.
Charge on the battery will show how much battery is left before complete discharge in a
percentage, the message will read "Battery Percentage Remaining: XXX%", where XXX
is the percentage from 0 to 100. Another message that will be displayed is the time until
shutdown. There will be a algorithm used to calculate a future time by using the power
consumption and charging to calculate when the device will run out of power and shut
down. The message will read "Charge time remaining before discharge XX:XX" were
XX: is the hours remaining on the battery and :XX is the minutes remaining on the
battery. There will also be an incorporation of power in compared to power out. This
feature will let the user know if they are drawing more power that is coming in or vice
versa. If the user is drawing less power that what is coming in the message that will be
displayed is, “You are using no stored energy". If the user is using more power than
what is coming in the message will display, "You are using current and stored energy".
To control all of these features we will be using buttons to flip through the various
messages.
The buttons that we will be using will be used to interact with the LCD screen. One of
the buttons will be used to scroll through the options that have been previously
described. There will also be a timeout after a certain amount of time which will cause
the screen to go dark to save power. We estimate the power saved will be small but
when increasing efficiently saving power in small amounts all over the system will end
up being exponentially increased throughout the process. There will also be a button to
turn off and on the screen manually incase the user does not want to wait until time
timeout to save more energy. The screen will light back up and blink a sequence when