Electricity monitor control module

## Electricity monitor control module ## 16 commercial power monitoring module, input use optocoupler PC817 isolation and prevent city electrical interference into the acquisition system, 220V direct access, do not need to buck and saves the cost of the circuit. The use of two 74HC245 circuit work cycle, by a pin to control the 74HC245 chip microcontroller, control. MAX813 to achieve the watchdog control, to prevent the external environment to interfere with the microcontroller, microcontroller timing to the MAX813 pulse, in the microcontroller does not work or the emergence of the death cycle, MAX813 generates a reset signal, microcontroller reset. Collected data through the serial port, the use of the 485 communication mode. ![enter image description here][1] ![enter image description here][2] ## AT89S52 low power microcontroller ## AT89S52 is a low power, high performance CMOS 8 bit microcontroller, with 8K system programmable Flash memory. High density nonvolatile memory technology is manufactured using Atmel's high density, fully compatible with industrial 80C51 product instructions and pins. The on-chip Flash allows the program memory to be reprogrammed in system, also suitable for conventional programming. On one chip, 8 bit CPU and Flash are available in the system, which makes the AT89S52 widely used in many embedded control applications. AT89S52 has the function of the following criteria: 8K bytes of flash, 256 bytes of ram, 32 I / O lines, watchdog timer, two data pointers, three 16 bit timer / counter, a six vector two-level interrupt structure, a full duplex serial port, on-chip crystal oscillator, and a clock circuit. In addition, the AT89S52 can be reduced to 0Hz static logic operation, supports 2 software selectable power saving modes. In idle mode, the CPU stops working, allowing the RAM, timer / timer, serial port and interrupt to continue to work. Power down protection mode, the RAM content is saved, the oscillator is frozen, the microcontroller all work to stop, until the next interrupt or hardware reset. ![enter image description here][3] Serial communication parameter interface type RS-485 The baud rate is 9600 Data bit 8 Parity check None Stop bit 1 Flow control None Communication protocol RTU Modbus Serial port protection ESD 1.5KV Serial lightning protection 600W Over current, over voltage is less than 240V, less than 80mA Power supply parameters 9-24VDC (recommended 12VDC) Current 12VDC 100mA Surge protection 1.5kW Power over voltage, over current 500mA, 60V Power consumption is less than 2W **program** #include sbit CSCTL0 = P2^5; sbit CSCTL1 = P2^4; sbit CSCTL2 = P2^3; sbit CTL485 = P2^6; sbit WTCHDOG = P2^7; sbit LED = P1^2; #define send 1 #define recieve 0 unsigned char digitaldata0 = 0; unsigned char digitaldata1 = 0; unsigned char digitaldata = 0; /*void delay100(unsigned int time); void delay1000(unsigned int time); void serialcomm_init( void ); void time0_initial (); void send_char_com( unsigned char ch);*/ [1]: https://easyeda.com/normal/doc-iuoiAS93J.png [2]: https://easyeda.com/normal/doc-Dd7DVd7pG.png [3]: /editor/20151121/565069ab867a4.jpg