Design of intelligent desk lamp based on BISS0001

Abstract: This paper introduces the main functional characteristics of the BISS0001 sensor signal processor chip, and gives a specific method of designing and making an intelligent desk lamp by using BISS0001 and the single-chip computer 89C51 to form a pyroelectric infrared sensor control circuit. The characteristic of this intelligent desk lamp is that the controller can automatically control the desk lamp on and off according to whether there is someone next to the desk lamp and the intensity of the light, so it is convenient to use and can achieve energy-saving effects.
Keywords: BISS0001; microcontroller; sensor; controller; energy saving

O Introduction
At present, desk lamps have become a necessity for thousands of households. However, they often waste a lot of energy due to forgetting to turn off the lights during use; when using them at night, they have to turn on the lights in the dark, which is very inconvenient. Most of the users of desk lamps are underage students. If they use desk lamps for a long time and sit in the wrong posture, their eyesight will be affected. This paper presents a design method for making an intelligent desk lamp based on a pyroelectric infrared sensor control circuit composed of BISS0001 and a single-chip computer 89C51. The controller of this method can automatically control the turning on and off of the desk lamp according to whether there is someone next to the desk lamp and the intensity of the light, so that people can use it more conveniently and achieve energy-saving effects.

1 BISS0001 and its characteristics
BISS0001 is a high-performance sensor signal processing integrated circuit. It is equipped with a pyroelectric infrared sensor and a small number of external components to form a passive pyroelectric infrared switch, so it can automatically and quickly turn on various incandescent lamps, fluorescent lamps, buzzers, automatic doors, electric fans, dryers and automatic wash basins. It is particularly suitable for sensitive areas such as corridors in enterprises, hotels, shopping malls, warehouses and families, or for automatic lighting, lighting and alarm systems in safe areas. The main functions of BISS001 are as follows:
it is a CMOS digital-analog hybrid special integrated circuit;
it has an independent high input impedance operational amplifier that can match a variety of sensors for signal processing;
it has a bidirectional amplitude detector that can effectively suppress interference;
it has a built-in delay timer and a blocking timer;
it has a novel structure, is stable and reliable, and has a wide adjustment range;
it has a built-in reference voltage, and the operating voltage range is 2 to 6V.
The pin distribution of the BISS0001 chip is shown in Figure 1.

2 System composition
The system composition block diagram of the intelligent desk lamp is shown in Figure 2. As can be seen from the figure, this system is mainly composed of power supply, sensor, signal processing unit, BISS0001 chip, MCU unit, buzzer, switch control unit and lamp. The power supply part outputs 12 V and 5 V voltages through 7812 and 7805 respectively. 12 V supplies power to LM324, and 5 V supplies power to the rest. The signal detection and processing part is composed of pyroelectric infrared sensor, photoresistor, signal processing unit and BISS0001 chip; the function of the sensor is to sense whether there is someone, so the pyroelectric infrared sensor is used. The sensor is only sensitive to infrared radiation with a wavelength of about 10μm (the wavelength of infrared radiation from the human body), and will not trigger the probe action for other objects except the human body; the function of the photoresistor is to sense the light intensity of the surrounding environment of the desk lamp; the MCU part uses the 89C5l single-chip microcomputer produced by ATMEL, which has the advantages of low price, simple development, convenient operation and encryption, so it has a very large market share. The function of the single chip is to process the signal sent by BISS0001 and send commands to the switch control unit and the buzzer; the buzzer unit mainly gives a warning signal according to the command issued by the MCU unit; the switch control unit is implemented by the digital-to-analog conversion chip DAC0832, and its task is to control the opening or closing of the desk lamp according to the command given by 89C51, thereby realizing the automatic control operation of the desk lamp.

3 Hardware circuit design
The power supply circuit of this system is shown in Figure 3. This part mainly uses integrated circuit modules 7805 and 7812 to provide 5 V and 12 V voltages.

Figure 4 shows the signal detection and processing unit circuit of this system. The pyroelectric infrared sensor is RE200B.
The MCU and control circuit are shown in Figure 5.

This part of the circuit consists of a single-chip microcomputer AT89C51, a decoder 74LS138, a digital-to-analog conversion chip DAC0832 and an amplifier LM324. The main task is to drive the light after amplifying the control signal through the amplifier LM324.
The buzzer reminder circuit in the system is shown in Figure 6.

4 Software Design
The following is part of the source code of the smart desk lamp software:

5 Conclusion
The popularity of desk lamps in households is very high. The smart desk lamp designed in this paper will definitely bring more convenience to family life and will definitely play a certain role in reducing students' myopia.