add a new DHT11_2022 type for 0.01 °C resolution devices

RIOT-OS · Jun 13, 2023 · e62c6b8 · e62c6b8
1 parent 44ebdad
commit e62c6b8
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Showing 3 changed files with 8 additions and 14 deletions.
diff --git a/drivers/dht/dht.c b/drivers/dht/dht.c
@@ -146,6 +146,7 @@ static int _parse_raw_values(dht_t *dev, uint8_t *data)
 
     switch (dev->params.type) {
     case DHT11:
+    case DHT11_2022:
         DEBUG_PUTS("[dht] parse raw values with DHT11 data format");
         dev->last_val.humidity = data[BYTEPOS_HUMIDITY_HIGH] * 10
                                + data[BYTEPOS_HUMIDITY_LOW];
@@ -155,13 +156,10 @@ static int _parse_raw_values(dht_t *dev, uint8_t *data)
         data[BYTEPOS_TEMPERATURE_LOW] &= ~0x80;
         /* 2022-12 aosong.com data sheet uses interprets low bits as
          * 0.01°C per LSB */
-        if (!dev->params.lsb_is_hundreds && data[BYTEPOS_TEMPERATURE_LOW] > 9) {
-            /* in case of miss configuration */
-            dev->params.lsb_is_hundreds = 1;
-        }
-        if (dev->params.lsb_is_hundreds) {
+        if (dev->params.type == DHT11_2022) {
             data[BYTEPOS_TEMPERATURE_LOW] /= 10;
         }
+        assert(data[BYTEPOS_TEMPERATURE_LOW] < 10);
         dev->last_val.temperature = data[BYTEPOS_TEMPERATURE_HIGH] * 10
                                   + data[BYTEPOS_TEMPERATURE_LOW];
         break;
@@ -198,7 +196,8 @@ int dht_init(dht_t *dev, const dht_params_t *params)
     /* check parameters and configuration */
     assert(dev && params);
     /* AM2301 == DHT21 == DHT22 (same value in enum) */
-    assert((params->type == DHT11) || (params->type == DHT22));
+    assert((params->type == DHT11) || (params->type == DHT11_2022)
+        || (params->type == DHT22));
 
     memset(dev, 0, sizeof(dht_t));
     dev->params = *params;

diff --git a/drivers/dht/include/dht_params.h b/drivers/dht/include/dht_params.h
@@ -37,17 +37,12 @@ extern "C" {
 #ifndef DHT_PARAM_TYPE
 #define DHT_PARAM_TYPE              (DHT11)
 #endif
-#ifndef DHT_PARAM_LSB_IS_HUNDREDS
-#define DHT_PARAM_LSB_IS_HUNDREDS   (0)
-#endif
 #ifndef DHT_PARAM_PULL
 #define DHT_PARAM_PULL              (GPIO_IN)
 #endif
 #ifndef DHT_PARAMS
 #define DHT_PARAMS                  { .pin     = DHT_PARAM_PIN,  \
                                       .type    = DHT_PARAM_TYPE, \
-                                      .lsb_is_hundreds = \
-                                      DHT_PARAM_LSB_IS_HUNDREDS, \
                                       .in_mode = DHT_PARAM_PULL }
 #endif
 #ifndef DHT_SAULINFO

diff --git a/drivers/include/dht.h b/drivers/include/dht.h
@@ -63,7 +63,9 @@ typedef struct {
  * @brief   Device type of the DHT device
  */
 typedef enum {
-    DHT11,                  /**< DHT11 device identifier */
+    DHT11,                  /**< Older DHT11 variants with either 1 °C or
+                              *  0.1 °C resolution */
+    DHT11_2022,             /**< New DHT11 variant with 0.01 °C resolution */
     DHT22,                  /**< DHT22 device identifier */
     DHT21 = DHT22,          /**< DHT21 device identifier */
     AM2301 = DHT22,         /**< AM2301 device identifier */
@@ -75,8 +77,6 @@ typedef enum {
 typedef struct {
     gpio_t pin;             /**< GPIO pin of the device's data pin */
     dht_type_t type;        /**< type of the DHT device */
-    bool lsb_is_hundreds;   /**< 2022-12 aosong.com data sheet uses interprets
-                             *   low bits as 0.01°C per LSB */
     gpio_mode_t in_mode;    /**< input pin configuration, with or without pull
                              *   resistor */
 } dht_params_t;