Design of intelligent desk lamp based on BISS0001

0 Preface

At present, desk lamps have become a necessity for thousands of households. However, they often waste a lot of energy because people forget to turn off the lights. 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, making it more convenient for people to use and achieving energy-saving effects.

1 BISS000l and its features

BISS0001 is a high-performance sensor signal processing integrated circuit. It can be 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, automatic wash basins and other devices. It is particularly suitable for sensitive areas such as corridors in enterprises, hotels, shopping malls, warehouses and homes, or for automatic lighting, illumination and alarm systems in safe areas. The main functions of BISS001 are as follows:

It is a CMOS digital-analog hybrid application-specific integrated circuit;

It has an independent high input impedance operational amplifier that can match a variety of sensors for signal processing;

Equipped with a bidirectional amplitude detector, it can effectively suppress interference;

Built-in delay timer and blocking time timer;

Novel structure, stable and reliable, wide adjustment range;

Built-in reference voltage, operating voltage range is 2 ~ 6V.

The pin distribution of the BISS0001 chip is shown in Figure 1.

2 System composition

The system block diagram of the intelligent desk lamp is shown in Figure 2. As can be seen from the figure, the system mainly consists of a power supply, a sensor, a signal processing unit, a BISS0001 chip, an MCU unit, a buzzer, a switch control unit and a lamp. The power supply 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 consists of a pyroelectric infrared sensor, a photoresistor, a signal processing unit and a BISS0001 chip; the function of the sensor is to sense whether there is someone, so a pyroelectric infrared sensor is used. The sensor is only sensitive to infrared radiation with a wavelength of about 10 μm (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, in which the pyroelectric infrared sensor is RE200B.

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 lamp after the control signal is amplified by the amplifier LM324.

The buzzer reminder circuit in the system is shown in Figure 6.

4 Software Design

Here are some source codes of the intelligent desk lamp software:

5 Conclusion

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