Specifications

68
USB Vcc +5VDC
USB Data -
USB Data +
USB Ground
MSP430G2231IN14
1
2
3
4
5
6
7
9
10
11
12
13
14
2KΩ
4.6KΩ
8
Battery Positive
Battery Negative
2KΩ
723Ω
MSP430G2231IN14
1
2
3
4
5
6
7
9
10
11
12
13
14
8
Current/Voltage Sensor
Inputs
Display Output
Vcc Gnd
Voltage Sense
Current Sense 2
Current Sense 3
Current Sense 4
Current Sense 5
Output
Gnd
Input
Vcc
D1
D2
D3
D4
D5 D6
D7
E
Figure 56 - Planned Schematic of Microcontrollers on PCB
As you can see in the figure above, we plan to use one of the USB outputs of the power
inverter to power the microprocessors. This will integrate them into the power
calculations for the power inverter, so one less current sensor will be needed. As you
can see, the 5VDC input by the USB cable is reduced via a voltage divider circuit. This
is because the suggested max voltage at Vcc for the microcontrollers is 3.6V. Using the
circuit shown in the above schematic, the voltage is dropped to approximately 3.49V,
which will work perfectly as it is well within the acceptable range.
5.6.1 Power Usage Sensors
Power usage of the system will be determined by looking at all of the energy being
generated by our solar and wind sources and how much power is being consumed by
each of our applications. These numbers will let us know if the battery is taking in
enough energy to store or if the system is using more than it is taking in, depleting the
battery. This information, being relevant to the user, will be displayed on the LCD
screen.
The energy produced by the wind turbine will be quite simple to monitor. As the
Sunforce 45444 comes with its own built in MPPT charge controller, the power that is
being output to the battery will be easy to monitor. This information will also be fed into
a microcontroller whose task it will be to compute the power usage of the system.
The energy from the solar panels, though slightly more difficult, will still be relatively
easy to compute. They will not come with their own charge controller, requiring us to