Tasmota/sonoff/xsns_htu21.ino

303 lines
7.5 KiB
C++

/*
xsns_htu21.ino - HTU21 temperature and humidity sensor support for Sonoff-Tasmota
Copyright (C) 2017 Heiko Krupp and Theo Arends
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef USE_I2C
#ifdef USE_HTU
/*********************************************************************************************\
* HTU21 - Temperature and Humidy
*
* Source: Heiko Krupp
\*********************************************************************************************/
#define HTU21_ADDR 0x40
#define SI7013_CHIPID 0x0D
#define SI7020_CHIPID 0x14
#define SI7021_CHIPID 0x15
#define HTU21_CHIPID 0x32
#define HTU21_READTEMP 0xE3
#define HTU21_READHUM 0xE5
#define HTU21_WRITEREG 0xE6
#define HTU21_READREG 0xE7
#define HTU21_RESET 0xFE
#define HTU21_HEATER_WRITE 0x51
#define HTU21_HEATER_READ 0x11
#define HTU21_SERIAL2_READ1 0xFC /* Read 3rd two Serial bytes */
#define HTU21_SERIAL2_READ2 0xC9 /* Read 4th two Serial bytes */
#define HTU21_HEATER_ON 0x04
#define HTU21_HEATER_OFF 0xFB
#define HTU21_RES_RH12_T14 0x00 // Default
#define HTU21_RES_RH8_T12 0x01
#define HTU21_RES_RH10_T13 0x80
#define HTU21_RES_RH11_T11 0x81
#define HTU21_CRC8_POLYNOM 0x13100
uint8_t htuaddr;
uint8_t htutype = 0;
uint8_t delayT;
uint8_t delayH = 50;
char htustype[7];
uint8_t check_crc8(uint16_t data)
{
for (uint8_t bit = 0; bit < 16; bit++) {
if (data & 0x8000) {
data = (data << 1) ^ HTU21_CRC8_POLYNOM;
} else {
data <<= 1;
}
}
return data >>= 8;
}
uint8_t htu21_readDeviceID(void)
{
uint16_t deviceID = 0;
uint8_t checksum = 0;
Wire.beginTransmission(HTU21_ADDR);
Wire.write(HTU21_SERIAL2_READ1);
Wire.write(HTU21_SERIAL2_READ2);
Wire.endTransmission();
Wire.requestFrom(HTU21_ADDR, 3);
deviceID = Wire.read() << 8;
deviceID |= Wire.read();
checksum = Wire.read();
if (check_crc8(deviceID) == checksum) {
deviceID = deviceID >> 8;
} else {
deviceID = 0;
}
return (uint8_t)deviceID;
}
void htu21_setRes(uint8_t resolution)
{
uint8_t current = i2c_read8(HTU21_ADDR, HTU21_READREG);
current &= 0x7E; // Replace current resolution bits with 0
current |= resolution; // Add new resolution bits to register
i2c_write8(HTU21_ADDR, HTU21_WRITEREG, current);
}
void htu21_reset(void)
{
Wire.beginTransmission(HTU21_ADDR);
Wire.write(HTU21_RESET);
Wire.endTransmission();
delay(15); // Reset takes 15ms
}
void htu21_heater(uint8_t heater)
{
uint8_t current = i2c_read8(HTU21_ADDR, HTU21_READREG);
switch(heater)
{
case HTU21_HEATER_ON : current |= heater;
break;
case HTU21_HEATER_OFF : current &= heater;
break;
default : current &= heater;
break;
}
i2c_write8(HTU21_ADDR, HTU21_WRITEREG, current);
}
boolean htu21_init()
{
htu21_reset();
htu21_heater(HTU21_HEATER_OFF);
htu21_setRes(HTU21_RES_RH12_T14);
return true;
}
float htu21_readHumidity(void)
{
uint8_t checksum = 0;
uint16_t sensorval = 0;
float humidity = 0.0;
Wire.beginTransmission(HTU21_ADDR);
Wire.write(HTU21_READHUM);
if (Wire.endTransmission() != 0) {
return 0.0; // In case of error
}
delay(delayH); // Sensor time at max resolution
Wire.requestFrom(HTU21_ADDR, 3);
if (3 <= Wire.available()) {
sensorval = Wire.read() << 8; // MSB
sensorval |= Wire.read(); // LSB
checksum = Wire.read();
}
if (check_crc8(sensorval) != checksum) {
return 0.0; // Checksum mismatch
}
sensorval ^= 0x02; // clear status bits
humidity = 0.001907 * (float)sensorval - 6;
if (humidity > 100) {
return 100.0;
}
if (humidity < 0) {
return 0.01;
}
return humidity;
}
float htu21_readTemperature()
{
uint8_t checksum=0;
uint16_t sensorval=0;
float t;
Wire.beginTransmission(HTU21_ADDR);
Wire.write(HTU21_READTEMP);
if (Wire.endTransmission() != 0) {
return 0.0; // In case of error
}
delay(delayT); // Sensor time at max resolution
Wire.requestFrom(HTU21_ADDR, 3);
if (3 == Wire.available()) {
sensorval = Wire.read() << 8; // MSB
sensorval |= Wire.read(); // LSB
checksum = Wire.read();
}
if (check_crc8(sensorval) != checksum) {
return 0.0; // Checksum mismatch
}
t = convertTemp(0.002681 * (float)sensorval - 46.85);
return t;
}
float htu21_compensatedHumidity(float humidity, float temperature)
{
if(humidity == 0.00 && temperature == 0.00) {
return 0.0;
}
if(temperature > 0.00 && temperature < 80.00) {
return (-0.15)*(25-temperature)+humidity;
}
}
uint8_t htu_detect()
{
if (htutype) {
return true;
}
boolean success = false;
htuaddr = HTU21_ADDR;
htutype = htu21_readDeviceID();
success = htu21_init();
switch (htutype) {
case HTU21_CHIPID:
strcpy_P(htustype, PSTR("HTU21"));
delayT=50;
delayH=16;
break;
case SI7013_CHIPID:
strcpy_P(htustype, PSTR("SI7013"));
delayT=12;
delayH=23;
break;
case SI7020_CHIPID:
strcpy_P(htustype, PSTR("SI7020"));
delayT=12;
delayH=23;
break;
case SI7021_CHIPID:
strcpy_P(htustype, PSTR("SI7021"));
delayT=12;
delayH=23;
break;
default:
strcpy_P(htustype, PSTR("T/RH?"));
delayT=50;
delayH=23;
}
if (success) {
snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_I2C "%s " D_FOUND_AT " 0x%x"), htustype, htuaddr);
addLog(LOG_LEVEL_DEBUG);
} else {
htutype = 0;
}
return success;
}
/*********************************************************************************************\
* Presentation
\*********************************************************************************************/
void htu_mqttPresent(uint8_t* djson)
{
if (!htutype) {
return;
}
char stemp1[10];
char stemp2[10];
float t = htu21_readTemperature();
float h = htu21_readHumidity();
h = htu21_compensatedHumidity(h, t);
dtostrfd(t, sysCfg.flag.temperature_resolution, stemp1);
dtostrfd(h, sysCfg.flag.humidity_resolution, stemp2);
snprintf_P(mqtt_data, sizeof(mqtt_data), JSON_SNS_TEMPHUM, mqtt_data, htustype, stemp1, stemp2);
*djson = 1;
#ifdef USE_DOMOTICZ
domoticz_sensor2(stemp1, stemp2);
#endif // USE_DOMOTICZ
}
#ifdef USE_WEBSERVER
String htu_webPresent()
{
String page = "";
if (htutype) {
char stemp[10];
char sensor[80];
float t_htu21 = htu21_readTemperature();
float h_htu21 = htu21_readHumidity();
h_htu21 = htu21_compensatedHumidity(h_htu21, t_htu21);
dtostrfi(t_htu21, sysCfg.flag.temperature_resolution, stemp);
snprintf_P(sensor, sizeof(sensor), HTTP_SNS_TEMP, htustype, stemp, tempUnit());
page += sensor;
dtostrfi(h_htu21, sysCfg.flag.humidity_resolution, stemp);
snprintf_P(sensor, sizeof(sensor), HTTP_SNS_HUM, htustype, stemp);
page += sensor;
}
return page;
}
#endif // USE_WEBSERVER
#endif // USE_HTU
#endif // USE_I2C