Extras/DHT improvements: makefile fix, replace DHT_TYPE macro by param (#252)

examples/dht_sensor/Makefile

@@ -1,4 +1,4 @@
-PROGRAM=dht_sensor
+PROGRAM = dht_sensor
 EXTRA_COMPONENTS = extras/dht
 include ../../common.mk
 

examples/dht_sensor/dht_sensor.c

@@ -8,7 +8,7 @@
 #include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
-#include "dht.h"
+#include <dht/dht.h>
 #include "esp8266.h"
 
 /* An example using the ubiquitous DHT** humidity sensors
@@ -16,6 +16,7 @@
  * from a sensor attached to GPIO pin 4.
  */
 uint8_t const dht_gpio = 4;
+const dht_sensor_type_t sensor_type = DHT_TYPE_DHT22;
 
 void dhtMeasurementTask(void *pvParameters)
 {
@@ -28,7 +29,7 @@ void dhtMeasurementTask(void *pvParameters)
     gpio_set_pullup(dht_gpio, false, false);
 
     while(1) {
-        if (dht_read_data(dht_gpio, &humidity, &temperature)) {
+        if (dht_read_data(sensor_type, dht_gpio, &humidity, &temperature)) {
             printf("Humidity: %d%% Temp: %dC\n", 
                     humidity / 10, 
                     temperature / 10);

extras/dht/component.mk

@@ -1,10 +1,10 @@
 # Component makefile for extras/dht
 
-INC_DIRS += $(ROOT)extras/dht
+# include it as 'dht/dht.h'
+INC_DIRS += $(dht_ROOT)..
 
 # args for passing into compile rule generation
-extras/dht_INC_DIR =  $(ROOT)extras/dht
+dht_SRC_DIR = $(dht_ROOT)
-extras/dht_SRC_DIR =  $(ROOT)extras/dht
 
-$(eval $(call component_compile_rules,extras/dht))
+$(eval $(call component_compile_rules,dht))
 

extras/dht/dht.c

@@ -18,7 +18,6 @@
 #define DHT_DATA_BITS 40
 
 // #define DEBUG_DHT
-
 #ifdef DEBUG_DHT
 #define debug(fmt, ...) printf("%s" fmt "\n", "dht: ", ## __VA_ARGS__);
 #else
@@ -116,7 +115,7 @@ static inline bool dht_fetch_data(uint8_t pin, bool bits[DHT_DATA_BITS])
             debug("LOW bit timeout\n");
             return false;
         }
-        if (!dht_await_pin_state(pin, 75, false, &high_duration)){
+        if (!dht_await_pin_state(pin, 75, false, &high_duration)) {
             debug("HIGHT bit timeout\n");
             return false;
         }
@@ -128,27 +127,26 @@ static inline bool dht_fetch_data(uint8_t pin, bool bits[DHT_DATA_BITS])
 /**
  * Pack two data bytes into single value and take into account sign bit.
  */
-static inline int16_t dht_convert_data(uint8_t msb, uint8_t lsb)
+static inline int16_t dht_convert_data(dht_sensor_type_t sensor_type, uint8_t msb, uint8_t lsb)
 {
     int16_t data;
 
-#if DHT_TYPE == DHT22
+    if (sensor_type == DHT_TYPE_DHT22) {
         data = msb & 0x7F;
         data <<= 8;
         data |= lsb;
         if (msb & BIT(7)) {
             data = 0 - data;       // convert it to negative
         }
-#elif DHT_TYPE == DHT11
+    }
+    else {
         data = msb * 10;
-#else
+    }
-#error "Unsupported DHT type"
-#endif
 
     return data;
 }
 
-bool dht_read_data(uint8_t pin, int16_t *humidity, int16_t *temperature)
+bool dht_read_data(dht_sensor_type_t sensor_type, uint8_t pin, int16_t *humidity, int16_t *temperature)
 {
     bool bits[DHT_DATA_BITS];
     uint8_t data[DHT_DATA_BITS/8] = {0};
@@ -175,19 +173,19 @@ bool dht_read_data(uint8_t pin, int16_t *humidity, int16_t *temperature)
         return false;
     }
 
-    *humidity = dht_convert_data(data[0], data[1]);
+    *humidity = dht_convert_data(sensor_type, data[0], data[1]);
-    *temperature = dht_convert_data(data[2], data[3]);
+    *temperature = dht_convert_data(sensor_type, data[2], data[3]);
 
     debug("Sensor data: humidity=%d, temp=%d\n", *humidity, *temperature);
 
     return true;
 }
 
-bool dht_read_float_data(uint8_t pin, float *humidity, float *temperature)
+bool dht_read_float_data(dht_sensor_type_t sensor_type, uint8_t pin, float *humidity, float *temperature)
 {
     int16_t i_humidity, i_temp;
 
-    if (dht_read_data(pin, &i_humidity, &i_temp)) {
+    if (dht_read_data(sensor_type, pin, &i_humidity, &i_temp)) {
         *humidity = (float)i_humidity / 10;
         *temperature = (float)i_temp / 10;
         return true;

extras/dht/dht.h

@@ -11,16 +11,19 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#define DHT11       11
-#define DHT22       22
-
-// Type of sensor to use
-#define DHT_TYPE    DHT22
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+ * Sensor type
+ */
+typedef enum
+{
+    DHT_TYPE_DHT11 = 0, //!< DHT11
+    DHT_TYPE_DHT22      //!< DHT22
+} dht_sensor_type_t;
+
 /**
  * Read data from sensor on specified pin.
  *
@@ -29,7 +32,7 @@ extern "C" {
  *              temperature=24.4 is 24.4 degrees Celsius
  *
  */
-bool dht_read_data(uint8_t pin, int16_t *humidity, int16_t *temperature);
+bool dht_read_data(dht_sensor_type_t sensor_type, uint8_t pin, int16_t *humidity, int16_t *temperature);
 
 
 /**
@@ -37,7 +40,7 @@ bool dht_read_data(uint8_t pin, int16_t *humidity, int16_t *temperature);
  *
  * Return values as floating point values.
  */
-bool dht_read_float_data(uint8_t pin, float *humidity, float *temperature);
+bool dht_read_float_data(dht_sensor_type_t sensor_type, uint8_t pin, float *humidity, float *temperature);
 
 #ifdef __cplusplus
 }