Tasmota/tasmota/xsns_06_dht.ino

358 lines
11 KiB
C++

/*
xsns_06_dht.ino - DHTxx, AM23xx and SI7021 temperature and humidity sensor support for Tasmota
Copyright (C) 2020 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_DHT
/*********************************************************************************************\
* DHT11, AM2301 (DHT21, DHT22, AM2302, AM2321), SI7021 - Temperature and Humidy
*
* Reading temperature or humidity takes about 250 milliseconds!
* Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
* Source: Adafruit Industries https://github.com/adafruit/DHT-sensor-library
\*********************************************************************************************/
#define XSNS_06 6
#define DHT_MAX_SENSORS 4
#define DHT_MAX_RETRY 8
uint32_t dht_max_cycles;
uint8_t dht_data[5];
uint8_t dht_sensors = 0;
uint8_t dht_pin_out = 0; // Shelly GPIO00 output only
bool dht_active = true; // DHT configured
bool dht_dual_mode = false; // Single pin mode
struct DHTSTRUCT {
uint8_t pin;
uint8_t type;
char stype[12];
uint32_t lastreadtime;
uint8_t lastresult;
float t = NAN;
float h = NAN;
} Dht[DHT_MAX_SENSORS];
void DhtReadPrep(void)
{
for (uint32_t i = 0; i < dht_sensors; i++) {
if (!dht_dual_mode) {
digitalWrite(Dht[i].pin, HIGH);
} else {
digitalWrite(dht_pin_out, HIGH);
}
}
}
int32_t DhtExpectPulse(uint8_t sensor, bool level)
{
int32_t count = 0;
while (digitalRead(Dht[sensor].pin) == level) {
if (count++ >= (int32_t)dht_max_cycles) {
return -1; // Timeout
}
}
return count;
}
bool DhtRead(uint8_t sensor)
{
int32_t cycles[80];
uint8_t error = 0;
dht_data[0] = dht_data[1] = dht_data[2] = dht_data[3] = dht_data[4] = 0;
if (Dht[sensor].lastresult > DHT_MAX_RETRY) {
Dht[sensor].lastresult = 0;
if (!dht_dual_mode) {
digitalWrite(Dht[sensor].pin, HIGH); // Retry read prep
} else {
digitalWrite(dht_pin_out, HIGH);
}
delay(250);
}
// Activate sensor using its protocol
noInterrupts();
if (!dht_dual_mode) {
pinMode(Dht[sensor].pin, OUTPUT);
digitalWrite(Dht[sensor].pin, LOW);
} else {
digitalWrite(dht_pin_out, LOW);
}
switch (Dht[sensor].type) {
case GPIO_SI7021: // Start protocol for iTead SI7021
/*
Protocol:
Reverse-engineered on https://github.com/arendst/Tasmota/issues/735#issuecomment-348718383:
1. MCU PULLS LOW data bus for at 500us to activate sensor
2. MCU PULLS UP data bus for ~40us to ask sensor for response
3. SENSOR starts sending data (LOW 40us then HIGH ~25us for "0" or ~75us for "1")
4. SENSOR sends "1" start bit as a response
5. SENSOR sends 16 bits (2 bytes) of a humidity with one decimal (i.e. 35.6% is sent as 356)
6. SENSOR sends 16 bits (2 bytes) of a temperature with one decimal (i.e. 23.4C is sent as 234)
7. SENSOR sends 8 bits (1 byte) checksum of 4 data bytes
*/
// digitalWrite(Dht[sensor].pin, LOW);
delayMicroseconds(500);
if (!dht_dual_mode) {
digitalWrite(Dht[sensor].pin, HIGH);
} else {
digitalWrite(dht_pin_out, HIGH);
}
delayMicroseconds(40);
break;
case GPIO_DHT22: // Start protocol for DHT21, DHT22, AM2301, AM2302, AM2321
/*
Protocol:
1. MCU PULLS LOW data bus for 1 to 10ms to activate sensor
2. MCU PULLS UP data bus for 20-40us to ask sensor for response
3. SENSOR PULLS LOW data bus for 80us as a response
4. SENSOR PULLS UP data bus for 80us for data sending preparation
5. SENSOR starts sending data (LOW 50us then HIGH 26-28us for "0" or 70us for "1")
*/
// digitalWrite(Dht[sensor].pin, LOW);
delayMicroseconds(1100); // data sheet says "at least 1ms to 10ms"
if (!dht_dual_mode) {
digitalWrite(Dht[sensor].pin, HIGH);
} else {
digitalWrite(dht_pin_out, HIGH);
}
delayMicroseconds(30); // data sheet says "20 to 40us"
break;
case GPIO_DHT11: // Start protocol for DHT11
/*
Protocol:
1. MCU PULLS LOW data bus for at least 18ms to activate sensor
2. MCU PULLS UP data bus for 20-40us to ask sensor for response
3. SENSOR PULLS LOW data bus for 80us as a response
4. SENSOR PULLS UP data bus for 80us for data sending preparation
5. SENSOR starts sending data (LOW 50us then HIGH 26-28us for "0" or 70 us for "1")
*/
default:
// digitalWrite(Dht[sensor].pin, LOW);
delay(20); // data sheet says at least 18ms, 20ms just to be safe
if (!dht_dual_mode) {
digitalWrite(Dht[sensor].pin, HIGH);
} else {
digitalWrite(dht_pin_out, HIGH);
}
delayMicroseconds(30); // data sheet says "20 to 40us"
break;
}
// Listen to the sensor response
pinMode(Dht[sensor].pin, INPUT_PULLUP);
if (-1 == DhtExpectPulse(sensor, LOW)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_START_SIGNAL_LOW " " D_PULSE));
error = 1;
}
else if (-1 == DhtExpectPulse(sensor, HIGH)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_START_SIGNAL_HIGH " " D_PULSE));
error = 1;
}
else {
for (uint32_t i = 0; i < 80; i += 2) {
cycles[i] = DhtExpectPulse(sensor, LOW);
cycles[i+1] = DhtExpectPulse(sensor, HIGH);
}
}
interrupts();
if (error) { return false; }
// Decode response
for (uint32_t i = 0; i < 40; ++i) {
int32_t lowCycles = cycles[2*i];
int32_t highCycles = cycles[2*i+1];
if ((-1 == lowCycles) || (-1 == highCycles)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_PULSE));
return false;
}
dht_data[i/8] <<= 1;
if (highCycles > lowCycles) {
dht_data[i / 8] |= 1;
}
}
// Check response
uint8_t checksum = (dht_data[0] + dht_data[1] + dht_data[2] + dht_data[3]) & 0xFF;
if (dht_data[4] != checksum) {
char hex_char[15];
AddLog_P2(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_CHECKSUM_FAILURE " %s =? %02X"),
ToHex_P(dht_data, 5, hex_char, sizeof(hex_char), ' '), checksum);
return false;
}
return true;
}
void DhtReadTempHum(uint8_t sensor)
{
if ((NAN == Dht[sensor].h) || (Dht[sensor].lastresult > DHT_MAX_RETRY)) { // Reset after 8 misses
Dht[sensor].t = NAN;
Dht[sensor].h = NAN;
}
if (DhtRead(sensor)) {
switch (Dht[sensor].type) {
case GPIO_DHT11:
Dht[sensor].h = dht_data[0];
Dht[sensor].t = dht_data[2] + ((float)dht_data[3] * 0.1f); // Issue #3164
break;
case GPIO_DHT22:
case GPIO_SI7021:
Dht[sensor].h = ((dht_data[0] << 8) | dht_data[1]) * 0.1;
Dht[sensor].t = (((dht_data[2] & 0x7F) << 8 ) | dht_data[3]) * 0.1;
if (dht_data[2] & 0x80) {
Dht[sensor].t *= -1;
}
break;
}
Dht[sensor].t = ConvertTemp(Dht[sensor].t);
Dht[sensor].h = ConvertHumidity(Dht[sensor].h);
Dht[sensor].lastresult = 0;
} else {
Dht[sensor].lastresult++;
}
}
/********************************************************************************************/
bool DhtPinState()
{
if ((XdrvMailbox.index >= GPIO_DHT11) && (XdrvMailbox.index <= GPIO_SI7021)) {
if (dht_sensors < DHT_MAX_SENSORS) {
Dht[dht_sensors].pin = XdrvMailbox.payload;
Dht[dht_sensors].type = XdrvMailbox.index;
dht_sensors++;
XdrvMailbox.index = GPIO_DHT11;
} else {
XdrvMailbox.index = 0;
}
return true;
}
return false;
}
void DhtInit(void)
{
if (dht_sensors) {
dht_max_cycles = microsecondsToClockCycles(1000); // 1 millisecond timeout for reading pulses from DHT sensor.
if (pin[GPIO_DHT11_OUT] < 99) {
dht_pin_out = pin[GPIO_DHT11_OUT];
dht_dual_mode = true; // Dual pins mode as used by Shelly
dht_sensors = 1; // We only support one sensor in pseudo mode
pinMode(dht_pin_out, OUTPUT);
}
for (uint32_t i = 0; i < dht_sensors; i++) {
pinMode(Dht[i].pin, INPUT_PULLUP);
Dht[i].lastreadtime = 0;
Dht[i].lastresult = 0;
GetTextIndexed(Dht[i].stype, sizeof(Dht[i].stype), Dht[i].type, kSensorNames);
if (dht_sensors > 1) {
snprintf_P(Dht[i].stype, sizeof(Dht[i].stype), PSTR("%s%c%02d"), Dht[i].stype, IndexSeparator(), Dht[i].pin);
}
}
AddLog_P2(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_SENSORS_FOUND " %d"), dht_sensors);
} else {
dht_active = false;
}
}
void DhtEverySecond(void)
{
if (uptime &1) {
// <1mS
DhtReadPrep();
} else {
for (uint32_t i = 0; i < dht_sensors; i++) {
// DHT11 and AM2301 25mS per sensor, SI7021 5mS per sensor
DhtReadTempHum(i);
}
}
}
void DhtShow(bool json)
{
for (uint32_t i = 0; i < dht_sensors; i++) {
char temperature[33];
dtostrfd(Dht[i].t, Settings.flag2.temperature_resolution, temperature);
char humidity[33];
dtostrfd(Dht[i].h, Settings.flag2.humidity_resolution, humidity);
if (json) {
ResponseAppend_P(JSON_SNS_TEMPHUM, Dht[i].stype, temperature, humidity);
#ifdef USE_DOMOTICZ
if ((0 == tele_period) && (0 == i)) {
DomoticzTempHumSensor(temperature, humidity);
}
#endif // USE_DOMOTICZ
#ifdef USE_KNX
if ((0 == tele_period) && (0 == i)) {
KnxSensor(KNX_TEMPERATURE, Dht[i].t);
KnxSensor(KNX_HUMIDITY, Dht[i].h);
}
#endif // USE_KNX
#ifdef USE_WEBSERVER
} else {
WSContentSend_PD(HTTP_SNS_TEMP, Dht[i].stype, temperature, TempUnit());
WSContentSend_PD(HTTP_SNS_HUM, Dht[i].stype, humidity);
#endif // USE_WEBSERVER
}
}
}
/*********************************************************************************************\
* Interface
\*********************************************************************************************/
bool Xsns06(uint8_t function)
{
bool result = false;
if (dht_active) {
switch (function) {
case FUNC_EVERY_SECOND:
DhtEverySecond();
break;
case FUNC_JSON_APPEND:
DhtShow(1);
break;
#ifdef USE_WEBSERVER
case FUNC_WEB_SENSOR:
DhtShow(0);
break;
#endif // USE_WEBSERVER
case FUNC_INIT:
DhtInit();
break;
case FUNC_PIN_STATE:
result = DhtPinState();
break;
}
}
return result;
}
#endif // USE_DHT