From 6d0545837c1792d8b5c363c600de79169ebe678a Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Fri, 13 Oct 2017 13:39:09 +0200
Subject: [PATCH] SHT3x driver - small changes

---
 .../sht3x/sht3x_one_sensor/sht3x_one_sensor.c | 35 +++++++++----------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/examples/sht3x/sht3x_one_sensor/sht3x_one_sensor.c b/examples/sht3x/sht3x_one_sensor/sht3x_one_sensor.c
index e906f1d..17fe6ba 100644
--- a/examples/sht3x/sht3x_one_sensor/sht3x_one_sensor.c
+++ b/examples/sht3x/sht3x_one_sensor/sht3x_one_sensor.c
@@ -16,6 +16,8 @@
  *   |          GPIO 4 (SDA)  ------- SDA      |
  *   +------------------------+     +----------+
  */
+
+// #define SINGLE_SHOT_MODE
  
 #include "espressif/esp_common.h"
 #include "esp/uart.h"
@@ -33,13 +35,11 @@
 
 static sht3x_sensor_t* sensor;    // sensor device data structure
 
-// #define SINGLE_SHOT_MODE
-
 #ifdef SINGLE_SHOT_MODE
 /*
- * User task that triggers measurements of sensor every 5 seconds. Due to
- * power efficiency reasons, it uses the SHT3x *single_shot* and *vTaskDelay*
- * to wait for measurement results.
+ * User task that triggers a measurement every 5 seconds. Due to
+ * power efficiency reasons, it uses the SHT3x *single_shot* and
+ * *vTaskDelay* to wait for measurement results.
  */
 void user_task (void *pvParameters)
 {
@@ -78,23 +78,23 @@ void user_task (void *pvParameters)
 {
     sht3x_values_t values;
 
-    // start periodic measurement mode
+    // start periodic measurements with 1 measurement per second
     sht3x_start_measurement (sensor, periodic_1mps);
 
-    // busy waiting until measurement results are available
+    // busy waiting until first measurement results are available
     while (sht3x_is_measuring (sensor) > 0) ;
 
     TickType_t last_wakeup = xTaskGetTickCount();
     
     while (1) 
     {
-        // retrieve the values and do something with them
+        // get the values and do something with them
         if (sht3x_get_results (sensor, &values))
             printf("%.3f SHT3x Sensor: %.2f °C, %.2f %%\n", 
                    (double)sdk_system_get_time()*1e-3,  
                    values.temperature, values.humidity);
-
-        // passive waiting until 2 seconds are over
+                   
+        // passive waiting until 2 seconds (cycle time) are over
         vTaskDelayUntil(&last_wakeup, 2000 / portTICK_PERIOD_MS);
     }
 }
@@ -102,10 +102,6 @@ void user_task (void *pvParameters)
 
 void user_init(void)
 {
-    // Please note: Return values are not considered in this example for 
-    // readability reasons. All functions return boolean and set an error
-    // code that allows effective error handling.
-    
     // Set UART Parameter
     uart_set_baud(0, 115200);
 
@@ -117,10 +113,11 @@ void user_init(void)
     i2c_init(I2C_BUS, I2C_SCL_PIN, I2C_SDA_PIN, I2C_FREQ_100K);
     
     // Create sensors
-    sensor = sht3x_init_sensor (I2C_BUS, SHT3x_ADDR_2);
-    
-    // Create a user task that uses the sensor
-    xTaskCreate(user_task, "user_task", 256, NULL, 2, 0);
-        
+    if ((sensor = sht3x_init_sensor (I2C_BUS, SHT3x_ADDR_2)))
+    {
+        // Create a user task that uses the sensor
+        xTaskCreate(user_task, "user_task", 256, NULL, 2, 0);
+    }
+
     // That's it.
 }