Design Requirements Specification
Software
Abstract
The energy-harvesting module will include a small
microprocessor to handle power management. The main responsibility
Mice are ubiquitous in today’s technology-driven world. However, it is a of this unit will be to monitor the charge remaining in the battery,
problem for those with the wireless variety to constantly change the batteries calculate the average operating time this will provide for the mouse,
in it. The solution is to modify a mouse such that it can power itself through its and inform the user when one of several conditions is met.
environment and user interaction. This will be implemented using a
The processor will read the charge remaining on the battery (in
combination of energy harvesting techniques, creating a mouse that is
mA / hours) and use it to calculate the mouse’s remaining runtime
functional and self-powering.
according to the equation
• Self-contained
•Self-charging
• Reliable
where T is the remaining time in hours, B is the remaining power in
mA / hours, and U is the average power consumption of the mouse in
mA. With this value, the processor will check for three conditions:
1. Self charging
• The user has requested the remaining life
2. Low to moderate cost
• The battery is full
3. Good quality of materials
• The operating time remaining is less than 1 hour.
4. Reliable
If one of these conditions is met, the microprocessor sends the
5. Self-contained
appropriate control signal to the notification hardware, a set of LEDs
6. Withstands the heat from sunlight
indicating how much operating time the mouse has before needing to
7. Flexible charging methods
be charged.
8. Long usage time from a full charge
The power management microprocessor will also be responsible
9. Includes battery meter and low battery alert
for switching the solar panels on and off based on their current output.
10. Comfortable use
Every minute, the microprocessor will turn on the solar panel, check
how much current the solar panels are producing, and turn them off if
they are producing less than their required operating current. This will
prevent the solar panels from slowly draining current at times when they
The power source for the mouse will come from four energy
are not in use, such as when the user is actively using the mouse.
harvesting methods, solar cells, piezoelectric, electromagnetic and a
mini dynamo. These will, in total, create enough stored energy to run
all of the wireless mouse’s electronics. Piezoelectric and
electromagnetic methods will operate passively, with just normal
usage. While the dynamo method will require user movement as an
input for power harvesting. The solar cells will assist in charging the
mouse when it is not in use. Each of the above mentioned methods
will require their own voltage regulation circuit to properly charge the
battery. The charge remaining will be available upon user request
through use of the user interface.
Marketing Requirements
Hardware
Hardware
Design Team 05
Amy Hicks – Computer Engineer – Archivist
Joel Howard – Computer Engineer – Software Manager
Cody Johnson – Electrical Engineer – Hardware Manager
Tara McCarthy – Electrical Engineer – Project Leader
Software
• 2011-2012 Senior Design Capstone Project • Dr. Nathan Ida and Dr. Hamid Bahrami, Faculty Advisors • Gregory A. Lewis, Senior Design Coordinator • Department of Electrical and Computer Engineering • College of Engineering • University of Akron •