太阳能邮箱项目电路,Solar Mailbox project

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太阳能邮箱项目电路,Solar Mailbox project
Final external Realization
The purpose of this project is to develop a self sufficient Mailbox (real one) that will be powered only by the sun and that will display the number of the house, but only in accordance with the battery level. The system must work autonomously when there is or not enough light to charge the battery.
At night: Central Digit On, other one in PWM Modes
The Mailbox is powered by a 5V/80mA Polysilicon solar cell. The sun energy is used to charge a 3 AA NiMH battery.
At night, when there is no light, the PIC is driving the 3 Digit according with a sequence which is defined in its program given in Annex.
Schematic Explanation



Behavioral Explanations
Apart when the Battery is totally low, the PIC is running and infinity loop which period is approximately 1 second, the red led is blinking accordingly.
During day light the SunSense signal is high and the PIC is not performing any operation (than the 1 second blinking loop). The Green led is on. If the battery voltage is low enough, the Solar cell is charging it. If the Battery voltage is above 4.6V (3 times 1.3V), then the DZ6 is drawing the current to ground protecting the battery cells. In the future Vbat_sense and Stop_Charge should be used.
During night the SunSense signal get low and the PIC is programmed t
- Generate a PWM signal (100Hz, Duty Cycle of 5%) on the PWM pin
- Generate a "blinking" sequence on the 3 separate control signals (1 minute period)
PIC Source code