基于ia4421分布式溫度和濕度采集系統(tǒng)(英語原文及翻譯)(編輯修改稿)
2025-07-04 18:08 本頁面
【文章內(nèi)容簡介】 TABLE3 IA4421 PINS Pin Name Type Function Pin1 SDI DIData input of the serial control interface Pin2 SCK DIClock input of the serial control interface Pin3 nSEL DIChip select input of the serial control interface (active low) Pin4 SDO DO Serial data output with bus holdPin5 NIRQ DO Interrupt request output (active low) Pin6 NFFS DI FIFO select input (active low） Pin7 FFIT DO FIFO interrupt (active high) Pin8 CLK DO Microcontroller clock outputIII. SYSTEM SOFTWARE OESIGN A. Software design of frontend monitoring unit The main function of the front end monitoring unit is to collect temperature and humidity parameters , and send to the information center , so its MCU software in addition to the main program , including temperature data acquisition and humidity data acquisition, the controlling of the wireless sending letter logic . In order to reduce power consumption, the microcontroller is always work in sleep mode [7] , it won39。t go into the collection and sending letter states until the wireless chip is woken up by the interrupt. In the system after the initialization is pleted, the MCU directly go into the sleep mode, then set flag B = 0 . When the wireless chip receives a wakeup signal, when external interrupt happens the interrupt request flag NIRQ output low to wake up the MCV . The external interrupt will set flag B=1, and then the system will collect data. The system flow chart is shown in Figure 3. Figure 3. Microcontroller controlling program flow chartPart of the main program of the frontend monitoring unit is shown below. void main() {ZHU_Init()。 IA_Init()。 While(1) {if(B==1) {WEN()。 SHI()。 CRC()。 FA()。 B=0。}}}In order to ensure the reliability of data transmission, design adds an 8bit CRC (cyclic redundancy check ) character, the CRC generator polynomial is : The generator polynomial of the logic circuit is shown in Figure 4. At the receiving end using the same CRC calculation in the data receiving, if the remainder is zero, then the checksum result is correct, or else it is the wrong data. Input MSB LSB Figure 4. logic circuitFront end monitoring units send five bytes each time to the monitoring center when sending data, its frame format is shown in Figure 5. AWDHWDLSHICRC Figure 5. The data frame format sending from frontend monitoring unit Figure 6. The flow chart monitoring center system Among them, the first byte A represents the serial numbers of frontend monitoring units, such as O1H, 02H and 03H. The second byte WDH is on behalf of 8 high bits of temperature data. The third byte WDL is on behalf of 8 low bits of temperature data. The fourth byte of SHI is converted humidity data . The fifth byte CRC is represented the remainder of the first four bytes of CRC which is encoded. B. Microcontroller software design of monitoring center The monitoring center39。s main function is to send polling signals, and to receive the collected temperature and humidity data . If the data is correct, the data will be sent to the host puter via RS232 . Monitoring center system flow chart is shown in Figure 6 .
教學(xué)教案相關(guān)推薦
鄂ICP備17016276號-1