arduino/libraries/Crowbits_DHT20/Crowbits_DHT20.cpp
2026-09-27 17:21:39 +02:00

109 lines
No EOL
2.5 KiB
C++

#include <Crowbits_DHT20.h>
Crowbits_DHT20::Crowbits_DHT20(TwoWire * pWire,uint8_t address)
: _pWire(pWire) {
_address = address;
}
int Crowbits_DHT20::begin() {
uint8_t readCMD[3]={0x71};
uint8_t data;
delay(100);
//_pWire->begin(14, 12);
//check if the IIC communication works
writeCommand(readCMD,1);
readData(&data, 1);
//Serial.println(data);
if((data | 0x8) == 0){
return 1;
}
if(data == 255) return 1;
return 0;
}
int Crowbits_DHT20::getTemperature() {
uint8_t readCMD[3]={0xac,0x33,0x00};
uint8_t data[6] = {0};
int retries = 10;
int temperature;
// when the returned data is wrong, request to get data again until the data is correct.
writeCommand(readCMD, 3);
while(retries--) {
delay(10);
readData(data,6);
if((data[0] >> 7) == 0){
// DBG("bus not busy");
break;
}
}
uint32_t temp = data[3] & 0xff;
uint32_t temp1 = data[4] & 0xff;
uint32_t rawData = 0;
rawData = ((temp&0xf)<<16)+(temp1<<8)+(data[5]);
//DBG(rawData);
//DBG((temp&0xf)<<16);
temperature = (int)rawData/5242 -50;
//DBG(temperature)
return temperature;
}
int Crowbits_DHT20::getHumidity() {
uint8_t readCMD[3]={0xac,0x33,0x00};
uint8_t data[6] = {0};
int retries = 10;
float humidity_f;
int humidity_i;
// when the returned data is wrong, request to get data again until the data is correct.
writeCommand(readCMD, 3);
while(retries--) {
delay(10);
readData(data,6);
if((data[0] >> 7) == 0){
//DBG("bus not busy");
break;
}
}
uint32_t temp = data[1] & 0xff;
uint32_t temp1 = data[2] & 0xff;
uint32_t rawData = 0;
rawData = (temp<<12)+(temp1<<4)+((data[3]&0xf0)>>4);
//DBG(rawData);
//DBG(temp<<12);
humidity_f = (float)rawData/0x100000;
humidity_i = (int)(humidity_f*100);
//DBG(humidity)
return humidity_i;
}
void Crowbits_DHT20::writeCommand(const void *pBuf, size_t size) {
if (pBuf == NULL) {
// DBG("pBuf ERROR!! : null pointer");
}
uint8_t * _pBuf = (uint8_t *)pBuf;
_pWire->beginTransmission(_address);
for (uint8_t i = 0; i < size; i++) {
_pWire->write(_pBuf[i]);
}
_pWire->endTransmission();
}
uint8_t Crowbits_DHT20::readData(void *pBuf, size_t size) {
delay(10);
if (pBuf == NULL) {
// DBG("pBuf ERROR!! : null pointer");
}
uint8_t * _pBuf = (uint8_t *)pBuf;
//read the data returned by the chip
_pWire->requestFrom(_address, size);
//uint8_t i = 0;
for (uint8_t i = 0 ; i < size; i++) {
_pBuf[i] = _pWire->read();
// DBG(_pBuf[i]);
}
return 1;
}