In the design of the time and attendance system, the hardware design is compatible with the design requirements of the master card and the slave card, so that the same PCB board can be configured as both the master card and the slave card. Including the design of master card and slave card, it is a compatible design block diagram. The design difference between the master card and the slave card is that the master card is powered by an external power supply and does not require external triggering; the slave card is powered by a battery and does not require a serial port.
The power supply module adopts a compatible design, which can be powered not only by an external power supply, but also by a battery. The main card mainly uses an external power supply to power the system. Slave cards are usually powered by batteries and are therefore easy to carry, so low-power design must be considered. Because the volume requirement of the RFID card is as small as possible, it can only be powered by a button battery. This system uses the largest button battery CR2477 with a capacity of 950mAH.
The main working principle of this system is to control the radio frequency chip to send and receive through the single chip microcomputer, and carry out the corresponding low power consumption management in different working states. The single chip microcomputer configures the radio frequency chip through pins. By setting the high and low levels of these three pins, Tianjin Smit Precision Instrument Co., Ltd. can configure the chip to work mode, standby mode or sleep mode.
After the card is initialized, the radio frequency chip enters the sleep mode, at which time the power consumption is the lowest. When triggered externally, the MCU is activated by the external interrupt of the pin, and the RF chip is configured in the sending mode. The MCU transmits data to the chip through the SPI mode, and the chip sends the high-frequency signal to the main card in the Shockburst mode. When the RF chip of the main card receives the correct high-frequency signal, it will generate an interrupt to the MCU through the pin. The MCU that was originally in the sleep mode is interrupted and activated, and the data is transmitted to the computer through the serial chip.
✿Special Function
-High Current Micro Switch
-Light force Micro Switch
-High&Low Pressure Switch
-3mm Contact Clearence Micro Switch
-Tubular Motor Switch
✿ Material
Made of high quality plastic and metal, rust resistance and corrosion resistance, durable enough for you to hanging items, So the product appearance is exquisite, perfect workmanship.
✿ Rating
You can meet the different RATING daily needs. Please pay attention to the model of the switch before purchase, to ensure that you purchase the same as you need.
✿ Vairous Sizes
Actuator Action is momentary and Actuator Type is long straight hinge lever. Switch Body Size as shown in the picture.So different sizes can meet all your daily different needs.
✿ Wide Application
Home appliance: micro oven, electric cooker, washing machine, electric heater, warmer, water fountain and so on.
Commercial appliance: Vending machine, electric toy, electric tools, duplicating machine and so on.
Machinery: Transport machinery, printing machinery, textile machinery and so on.
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Ningbo Jialin Electronics Co.,Ltd , https://www.donghai-switch.com