Tasmota/sonoff/xsns_dht.ino

266 lines
7.0 KiB
C++

/*
xsns_dht.ino - DHTxx and AM23xx temperature and humidity sensor support for Sonoff-Tasmota
Copyright (C) 2017 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, DHT21 (AM2301), DHT22 (AM2302, AM2321) - 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 DHT_MAX_SENSORS 3
#define MIN_INTERVAL 2000
uint32_t dht_max_cycles;
uint8_t dht_data[5];
byte dht_sensors = 0;
struct DHTSTRUCT {
byte pin;
byte type;
char stype[10];
uint32_t lastreadtime;
uint16_t lastresult;
float t;
float h = 0;
} dht[DHT_MAX_SENSORS];
void DhtReadPrep()
{
for (byte i = 0; i < dht_sensors; i++) {
digitalWrite(dht[i].pin, HIGH);
}
}
uint32_t DhtExpectPulse(byte sensor, bool level)
{
uint32_t count = 0;
while (digitalRead(dht[sensor].pin) == level) {
if (count++ >= dht_max_cycles) {
return 0;
}
}
return count;
}
void DhtRead(byte sensor)
{
uint32_t cycles[80];
uint32_t currenttime = millis();
if ((currenttime - dht[sensor].lastreadtime) < 2000) {
return;
}
dht[sensor].lastreadtime = currenttime;
dht_data[0] = dht_data[1] = dht_data[2] = dht_data[3] = dht_data[4] = 0;
// digitalWrite(dht[sensor].pin, HIGH);
// delay(250);
pinMode(dht[sensor].pin, OUTPUT);
digitalWrite(dht[sensor].pin, LOW);
delay(20);
noInterrupts();
digitalWrite(dht[sensor].pin, HIGH);
delayMicroseconds(40);
pinMode(dht[sensor].pin, INPUT_PULLUP);
delayMicroseconds(10);
if (0 == DhtExpectPulse(sensor, LOW)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_START_SIGNAL_LOW " " D_PULSE));
dht[sensor].lastresult++;
return;
}
if (0 == DhtExpectPulse(sensor, HIGH)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_START_SIGNAL_HIGH " " D_PULSE));
dht[sensor].lastresult++;
return;
}
for (int i = 0; i < 80; i += 2) {
cycles[i] = DhtExpectPulse(sensor, LOW);
cycles[i+1] = DhtExpectPulse(sensor, HIGH);
}
interrupts();
for (int i=0; i<40; ++i) {
uint32_t lowCycles = cycles[2*i];
uint32_t highCycles = cycles[2*i+1];
if ((0 == lowCycles) || (0 == highCycles)) {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_TIMEOUT_WAITING_FOR " " D_PULSE));
dht[sensor].lastresult++;
return;
}
dht_data[i/8] <<= 1;
if (highCycles > lowCycles) {
dht_data[i/8] |= 1;
}
}
snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DHT D_RECEIVED " %02X, %02X, %02X, %02X, %02X =? %02X"),
dht_data[0], dht_data[1], dht_data[2], dht_data[3], dht_data[4], (dht_data[0] + dht_data[1] + dht_data[2] + dht_data[3]) & 0xFF);
AddLog(LOG_LEVEL_DEBUG);
if (dht_data[4] == ((dht_data[0] + dht_data[1] + dht_data[2] + dht_data[3]) & 0xFF)) {
dht[sensor].lastresult = 0;
} else {
AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_DHT D_CHECKSUM_FAILURE));
dht[sensor].lastresult++;
}
}
boolean DhtReadTempHum(byte sensor, float &t, float &h)
{
if (!dht[sensor].h) {
t = NAN;
h = NAN;
} else {
if (dht[sensor].lastresult > 8) { // Reset after 8 misses
dht[sensor].t = NAN;
dht[sensor].h = NAN;
}
t = dht[sensor].t;
h = dht[sensor].h;
}
DhtRead(sensor);
if (!dht[sensor].lastresult) {
switch (dht[sensor].type) {
case GPIO_DHT11:
h = dht_data[0];
t = ConvertTemp(dht_data[2]);
break;
case GPIO_DHT22:
case GPIO_DHT21:
h = dht_data[0];
h *= 256;
h += dht_data[1];
h *= 0.1;
t = dht_data[2] & 0x7F;
t *= 256;
t += dht_data[3];
t *= 0.1;
if (dht_data[2] & 0x80) {
t *= -1;
}
t = ConvertTemp(t);
break;
}
if (!isnan(t)) {
dht[sensor].t = t;
}
if (!isnan(h)) {
dht[sensor].h = h;
}
}
return (!isnan(t) && !isnan(h));
}
boolean DhtSetup(byte pin, byte type)
{
boolean success = false;
if (dht_sensors < DHT_MAX_SENSORS) {
dht[dht_sensors].pin = pin;
dht[dht_sensors].type = type;
dht_sensors++;
success = true;
}
return success;
}
void DhtInit()
{
dht_max_cycles = microsecondsToClockCycles(1000); // 1 millisecond timeout for reading pulses from DHT sensor.
for (byte i = 0; i < dht_sensors; i++) {
pinMode(dht[i].pin, INPUT_PULLUP);
dht[i].lastreadtime = 0;
dht[i].lastresult = 0;
switch (dht[i].type) {
case GPIO_DHT11:
strcpy_P(dht[i].stype, PSTR("DHT11"));
break;
case GPIO_DHT21:
strcpy_P(dht[i].stype, PSTR("AM2301"));
break;
case GPIO_DHT22:
strcpy_P(dht[i].stype, PSTR("DHT22"));
}
if (dht_sensors > 1) {
snprintf_P(dht[i].stype, sizeof(dht[i].stype), PSTR("%s-%02d"), dht[i].stype, dht[i].pin);
}
}
}
/*********************************************************************************************\
* Presentation
\*********************************************************************************************/
void MqttShowDht(uint8_t* djson)
{
char stemp1[10];
char stemp2[10];
float t;
float h;
byte dsxflg = 0;
for (byte i = 0; i < dht_sensors; i++) {
if (DhtReadTempHum(i, t, h)) { // Read temperature
dtostrfd(t, Settings.flag.temperature_resolution, stemp1);
dtostrfd(h, Settings.flag.humidity_resolution, stemp2);
snprintf_P(mqtt_data, sizeof(mqtt_data), JSON_SNS_TEMPHUM, mqtt_data, dht[i].stype, stemp1, stemp2);
*djson = 1;
#ifdef USE_DOMOTICZ
if (!dsxflg) {
DomoticzTempHumSensor(stemp1, stemp2);
dsxflg++;
}
#endif // USE_DOMOTICZ
}
}
}
#ifdef USE_WEBSERVER
String WebShowDht()
{
String page = "";
char stemp[10];
char sensor[80];
float t;
float h;
for (byte i = 0; i < dht_sensors; i++) {
if (DhtReadTempHum(i, t, h)) {
dtostrfi(t, Settings.flag.temperature_resolution, stemp);
snprintf_P(sensor, sizeof(sensor), HTTP_SNS_TEMP, dht[i].stype, stemp, TempUnit());
page += sensor;
dtostrfi(h, Settings.flag.humidity_resolution, stemp);
snprintf_P(sensor, sizeof(sensor), HTTP_SNS_HUM, dht[i].stype, stemp);
page += sensor;
}
}
return page;
}
#endif // USE_WEBSERVER
#endif // USE_DHT