Solar LED intelligent street lamp lighting system based on single chip microcomputer

The rapid development of China's economy is accompanied by a large number of energy consumption, conserve resources and protect the environment is a basic policy of the government to the current national advocate environmental protection and renewable energy (hydropower, wind power, solar power and so on) development, especially the use of solar energy. Based on this, a solar LED street lamp controller design based on single chip, the battery charging and LED lighting using solar energy, and with over charge, over discharge protection function, can according to the street lighting system during the day and night brightness automatic startup and shutdown LED lights intelligent function.

1 system architecture

Figure 1 is the structure of the system, which is composed of 7 modules, namely, the main control module, data acquisition module, display module, overcharge protection module, over discharge protection module, light control module and remote control module. 1) the main control module is mainly responsible for data processing and external circuit control; 2) the data acquisition module is mainly used for collecting the voltage across the battery and convert it into digital output; 3) display module is mainly used to display the current voltage and time; 4) overcharge protection module is mainly used to avoid excessive charging the battery is damaged; 5) discharge module is mainly used to avoid excessive battery discharge and damage; 6) photoelectric module is mainly used to start and shut down LLED lights automatically according to the brightness of day and night; 7) remote control module is mainly used for the artificial control of LED lights.

2 system hardware design

2.1 master and data acquisition module

The main control and data acquisition circuit as shown in Figure 2, including the smallest single-chip system and A / D0809 chip, the microcontroller P1 port to send digital tube display data; P0 port A / D0809 chip data output terminal, for receiving the ADC data; ALE (30 pin) connected to the A / D0809 CLOCK terminal. For providing a clock signal to the A / D0809; P2.7, P2.6 are used for the control over charge and discharge circuit, through the change of the level of the 2 end of the circuit, overcharge and overdischarge protection and the indicator lights off control; P2.5 connection A / D0809 OE terminal, is used to control the A / D0809 conversion output allow P2.4 to connect to the A / D0809 conversion; the starting end of the START, used to control the AD conversion start signal; P2.3 connected to the A / D0809 address latch end ALE, used to control the address latch signal; P2.0, P2.1, P2.2 connected to the A / D0809 analog channel Address ADDA, ADDB, ADDC, for analog channel selection. The main control circuit functions: microcontroller through P2.0, P2.1, P2.2 A / D0809 ADDA, ADDB, ADDC, A / D0809 analog IN0 input terminal as the analog signal input, A / D0809 through internal AD conversion, the analog voltage signal into digital signal and transmitted to the microcontroller through the data port of the microcontroller through the a series of process control digital tube display and charge discharge control terminal.

2.2 over charge and discharge control module

Charge control is in the battery is charging state is disconnected from the charging circuit, over discharge control is put in the battery is broken open circuit state. Over charge and over discharge control is to protect the battery and prolong the service life of the battery. Overcharge and over discharge judgment is based on the battery voltage. Its functions: the switch control circuit, overcharge relay J1 Series in the charging circuit, when in the normal state of charge during the day when the sun, the solar panel by the endothermic relay switch normally closed to the battery when the battery voltage is higher than 26 V, that the battery is charging state, the circuit to the P2.6 send a low level, so that the relay coil J1 is energized, the relay is normally closed off, normally open closed, disconnect the charging circuit, charging indicator light, stop to the battery charging, overcharge protection function to achieve. The switch of the relay J2 is connected in series with the discharge circuit in the over discharge control circuit. In the evening by the battery power to the load, when the battery voltage is lower than 10.3 V, that the battery is placed at the state, the circuit to the P2.7 send a low level, so that the relay coil J2 is energized by the relay switch normally closed to open, the discharge circuit is disconnected, put the light stop, to supply the load to over discharge protection function, the module circuit is shown in figure 3.

2.3 display circuit module

Figure 4 shows the digital control circuit, the circuit uses a parallel port display, the 741s373 as a digital tube drive and bit selection circuit, digital tube used to display the current time, as well as the current voltage. 741s373 selected LE2, LE3, LE1, LE4 are respectively connected with the microcontroller P3.4, P3.5, P3.6, P3.7 port, 741s373 MCU through each a choice, choose the digital tube display to display the current encoding, and then select another choice, encoding into the display, in order to realize the digital control of static class push. Display.

2.4 photosensitive resistance control module

The use of single-chip normally low level should be lower than 0.8 V features, combined with the characteristics of photosensitive resistance by the light sensitive impact resistance changes, through the photosensitive resistor and a fixed resistor series, namely by detecting the fixed resistor divider value to detect the day and the night. When the night when the design of fixed resistance value of pressure is less than 0.8 V, the microcontroller pin low level range, this time through the microcontroller to send P2.7 high level, the discharge circuit, LED, or LED out.

3 system software design

Figure 5 shows the program flow chart of the system,