119 lines
No EOL
2.8 KiB
C++
119 lines
No EOL
2.8 KiB
C++
/*!
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*@file DFRobot_DHT20.cpp
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*@brief Define the basic structure of class DFRobot_DHT20, the implementation of the basic methods
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*@copyright Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
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*@licence The MIT License (MIT)
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*@author [fengli](li.feng@dfrobot.com)
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*@version V1.0
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*@date 2021-6-24
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*@get from https://www.dfrobot.com
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*@https://github.com/DFRobot/DFRobot_DHT20
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*/
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#include <DFRobot_DHT20.h>
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DFRobot_DHT20::DFRobot_DHT20(TwoWire * pWire,uint8_t address)
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: _pWire(pWire) {
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_address = address;
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}
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int DFRobot_DHT20::begin() {
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uint8_t readCMD[3]={0x71};
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uint8_t data;
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delay(100);
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_pWire->begin();
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//check if the IIC communication works
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writeCommand(readCMD,1);
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readData(&data, 1);
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//Serial.println(data);
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if((data | 0x8) == 0){
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return 1;
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}
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if(data == 255) return 1;
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return 0;
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}
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float DFRobot_DHT20::getTemperature() {
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uint8_t readCMD[3]={0xac,0x33,0x00};
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uint8_t data[6] = {0};
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int retries = 10;
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float temperature;
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// when the returned data is wrong, request to get data again until the data is correct.
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writeCommand(readCMD, 3);
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while(retries--) {
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delay(10);
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readData(data,6);
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if((data[0] >> 7) == 0){
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DBG("bus not busy");
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break;
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}
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}
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uint32_t temp = data[3] & 0xff;
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uint32_t temp1 = data[4] & 0xff;
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uint32_t rawData = 0;
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rawData = ((temp&0xf)<<16)+(temp1<<8)+(data[5]);
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DBG(rawData);
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DBG((temp&0xf)<<16);
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temperature = (float)rawData/5242 -50;
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DBG(temperature)
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return temperature;
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}
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float DFRobot_DHT20::getHumidity() {
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uint8_t readCMD[3]={0xac,0x33,0x00};
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uint8_t data[6] = {0};
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int retries = 10;
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float humidity;
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// when the returned data is wrong, request to get data again until the data is correct.
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writeCommand(readCMD, 3);
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while(retries--) {
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delay(10);
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readData(data,6);
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if((data[0] >> 7) == 0){
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DBG("bus not busy");
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break;
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}
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}
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uint32_t temp = data[1] & 0xff;
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uint32_t temp1 = data[2] & 0xff;
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uint32_t rawData = 0;
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rawData = (temp<<12)+(temp1<<4)+((data[3]&0xf0)>>4);
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DBG(rawData);
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DBG(temp<<12);
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humidity = (float)rawData/0x100000;
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DBG(humidity)
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return humidity;
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}
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void DFRobot_DHT20::writeCommand(const void *pBuf, size_t size) {
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if (pBuf == NULL) {
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DBG("pBuf ERROR!! : null pointer");
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}
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uint8_t * _pBuf = (uint8_t *)pBuf;
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_pWire->beginTransmission(_address);
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for (uint8_t i = 0; i < size; i++) {
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_pWire->write(_pBuf[i]);
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}
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_pWire->endTransmission();
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}
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uint8_t DFRobot_DHT20::readData(void *pBuf, size_t size) {
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delay(10);
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if (pBuf == NULL) {
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DBG("pBuf ERROR!! : null pointer");
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}
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uint8_t * _pBuf = (uint8_t *)pBuf;
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//read the data returned by the chip
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_pWire->requestFrom(_address, size);
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uint8_t i = 0;
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for (uint8_t i = 0 ; i < size; i++) {
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_pBuf[i] = _pWire->read();
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DBG(_pBuf[i]);
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}
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return 1;
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} |