Add DHT22 support

CMakeLists.txt

@@ -0,0 +1,4 @@
+idf_component_register(SRCS "dht.c"
+                    INCLUDE_DIRS include
+                    REQUIRES driver
+                    PRIV_REQUIRES soc)

README.md

@@ -1,15 +1,15 @@
 # ESP32-DHT11
-Esp-idf driver for DHT11 temperature and humidity sensor
+Esp-idf driver for DHT11/22 temperature and humidity sensor
 
 ## Install
 Use Platformio to install this [link](https://platformio.org/lib/show/5817/ESP32-DHT11)<br/>
 or <br/>
 Clone this repo inside [esp]/esp-idf/components folder
 
 ## How to use
-Import dht11.h inside your program, initialize the device with DHT11_init(gpio_num) and then call DHT11_read() whenever you need to read from the DHT11 sensor.<br/>
+Import dht.h inside your program, initialize the device with DHT11_init(gpio_num) or DHT22_init(gpio_num) and then call DHT_read() whenever you need to read from the DHT11/22 sensor.<br/>
 DHT11_read() returns a struct with temperature and humidity and a status code of the operation for error checking.<br/>
 
 Check the examples folder for more information.
 
-<b>WARNING</b>: DHT11_read() is a blocking function.
+<b>WARNING</b>: DHT_read() is a blocking function.

dht11.c → dht.c

@@ -23,32 +23,48 @@
 */
 
 #include "esp_timer.h"
+#include <esp_log.h>
 #include "driver/gpio.h"
 #include "rom/ets_sys.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 
-#include "dht11.h"
+#include "dht.h"
+
+typedef enum{
+	MODE_DHT11,
+	MODE_DHT22
+}dht_mode_t;
+
+#define TAG "dht-drv"
 
 static gpio_num_t dht_gpio;
+static dht_mode_t dht_mode;
 static int64_t last_read_time = -2000000;
-static struct dht11_reading last_read;
+static struct dht_reading last_read;
 
 static int _waitOrTimeout(uint16_t microSeconds, int level) {
     int micros_ticks = 0;
     while(gpio_get_level(dht_gpio) == level) { 
         if(micros_ticks++ > microSeconds) 
-            return DHT11_TIMEOUT_ERROR;
+            return DHT_TIMEOUT_ERROR;
         ets_delay_us(1);
     }
     return micros_ticks;
 }
 
 static int _checkCRC(uint8_t data[]) {
-    if(data[4] == (data[0] + data[1] + data[2] + data[3]))
-        return DHT11_OK;
+    if(data[4] == ((data[0] + data[1] + data[2] + data[3])&0xFF))
+        return DHT_OK;
     else
-        return DHT11_CRC_ERROR;
+		ESP_LOGD(TAG,"Crc error: %02x != %02x+%02x+%02x+%02x"
+				,data[4]
+				,data[0]
+				,data[1]
+				,data[2]
+				,data[3]
+				);
+        return DHT_CRC_ERROR;
 }
 
 static void _sendStartSignal() {
@@ -62,34 +78,44 @@ static void _sendStartSignal() {
 
 static int _checkResponse() {
     /* Wait for next step ~80us*/
-    if(_waitOrTimeout(80, 0) == DHT11_TIMEOUT_ERROR)
-        return DHT11_TIMEOUT_ERROR;
+    if(_waitOrTimeout(80, 0) == DHT_TIMEOUT_ERROR)
+        return DHT_TIMEOUT_ERROR;
 
     /* Wait for next step ~80us*/
-    if(_waitOrTimeout(80, 1) == DHT11_TIMEOUT_ERROR) 
-        return DHT11_TIMEOUT_ERROR;
+    if(_waitOrTimeout(80, 1) == DHT_TIMEOUT_ERROR) 
+        return DHT_TIMEOUT_ERROR;
 
-    return DHT11_OK;
+    return DHT_OK;
 }
 
-static struct dht11_reading _timeoutError() {
-    struct dht11_reading timeoutError = {DHT11_TIMEOUT_ERROR, -1, -1};
+static struct dht_reading _timeoutError() {
+    struct dht_reading timeoutError = {DHT_TIMEOUT_ERROR, -1, -1};
     return timeoutError;
 }
 
-static struct dht11_reading _crcError() {
-    struct dht11_reading crcError = {DHT11_CRC_ERROR, -1, -1};
+static struct dht_reading _crcError() {
+    struct dht_reading crcError = {DHT_CRC_ERROR, -1, -1};
     return crcError;
 }
 
-void DHT11_init(gpio_num_t gpio_num) {
+static void DHT_init(gpio_num_t gpio_num, dht_mode_t _dht_mode){
     /* Wait 1 seconds to make the device pass its initial unstable status */
     vTaskDelay(1000 / portTICK_PERIOD_MS);
     dht_gpio = gpio_num;
+	dht_mode = _dht_mode;
 }
 
-struct dht11_reading DHT11_read() {
-    /* Tried to sense too son since last read (dht11 needs ~2 seconds to make a new read) */
+void DHT11_init(gpio_num_t gpio_num) {
+	DHT_init(gpio_num, MODE_DHT11);
+}
+
+void DHT22_init(gpio_num_t gpio_num) {
+	DHT_init(gpio_num, MODE_DHT22);
+}
+
+
+struct dht_reading DHT_read() {
+    /* Tried to sense too son since last read (dht needs ~2 seconds to make a new read) */
     if(esp_timer_get_time() - 2000000 < last_read_time) {
         return last_read;
     }
@@ -100,13 +126,13 @@ struct dht11_reading DHT11_read() {
 
     _sendStartSignal();
 
-    if(_checkResponse() == DHT11_TIMEOUT_ERROR)
+    if(_checkResponse() == DHT_TIMEOUT_ERROR)
         return last_read = _timeoutError();
 
     /* Read response */
     for(int i = 0; i < 40; i++) {
         /* Initial data */
-        if(_waitOrTimeout(50, 0) == DHT11_TIMEOUT_ERROR)
+        if(_waitOrTimeout(50, 0) == DHT_TIMEOUT_ERROR)
             return last_read = _timeoutError();
 
         if(_waitOrTimeout(70, 1) > 28) {
@@ -115,10 +141,16 @@ struct dht11_reading DHT11_read() {
         }
     }
 
-    if(_checkCRC(data) != DHT11_CRC_ERROR) {
-        last_read.status = DHT11_OK;
-        last_read.temperature = data[2];
-        last_read.humidity = data[0];
+    if(_checkCRC(data) != DHT_CRC_ERROR) {
+        last_read.status = DHT_OK;
+		if (dht_mode == MODE_DHT11){
+	        last_read.temperature = data[2];
+		    last_read.humidity = data[0];
+		} else if (dht_mode == MODE_DHT22 ) {
+			last_read.temperature = ((data[2]<<8) + data[3])/10;
+			last_read.humidity = ((data[0]<<8) + data[1])/10;
+		} else {
+		};
         return last_read;
     } else {
         return last_read = _crcError();

include/dht11.h → include/dht.h

@@ -22,25 +22,27 @@
  * SOFTWARE.
 */
 
-#ifndef DHT11_H_
-#define DHT11_H_
+#ifndef DHT_H_
+#define DHT_H_
 
 #include "driver/gpio.h"
 
-enum dht11_status {
-    DHT11_CRC_ERROR = -2,
-    DHT11_TIMEOUT_ERROR,
-    DHT11_OK
+enum dht_status {
+    DHT_CRC_ERROR = -2,
+    DHT_TIMEOUT_ERROR,
+    DHT_OK
 };
 
-struct dht11_reading {
+struct dht_reading {
     int status;
-    int temperature;
-    int humidity;
+    float temperature;
+	float humidity;
 };
 
 void DHT11_init(gpio_num_t);
 
-struct dht11_reading DHT11_read();
+void DHT22_init(gpio_num_t);
 
-#endif
+struct dht_reading DHT_read();
+
+#endif