tests/driver_dht: adapted to driver changes

tests/driver_dht/Makefile

@@ -2,6 +2,7 @@ APPLICATION = driver_dht
 include ../Makefile.tests_common
 
 USEMODULE += dht
+USEMODULE += fmt
 USEMODULE += xtimer
 
 include $(RIOTBASE)/Makefile.include

tests/driver_dht/main.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2015 Ludwig Knüpfer, Christian Mehlis
- *               2016 Freie Universität Berlin
+ *               2016-2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
@@ -24,41 +24,48 @@
 #include <stdio.h>
 
 #include "xtimer.h"
+#include "timex.h"
+#include "fmt.h"
 #include "dht.h"
 #include "dht_params.h"
 
-extern dht_t dht_devs[];
+#define DELAY           (2 * US_PER_SEC)
 
 int main(void)
 {
+    dht_t dev;
+    int16_t temp, hum;
+    char temp_s[10];
+    char hum_s[10];
+
     puts("DHT temperature and humidity sensor test application\n");
 
+    /* initialize first configured sensor */
+    printf("Initializing DHT sensor...\t");
+    if (dht_init(&dev, &dht_params[0]) == DHT_OK) {
+        puts("[OK]\n");
+    }
+    else {
+        puts("[Failed]");
+        return 1;
+    }
+
     /* periodically read temp and humidity values */
     while (1) {
-        for (unsigned i = 0; i < DHT_NUMOF; i++) {
-            dht_t *dev = &dht_devs[i];
-            int16_t temp, hum;
-            int16_t dec_temp, dec_hum, int_temp, int_hum;
-
-            if (dht_read(dev, &temp, &hum) == -1) {
-                puts("error reading data");
-                continue;
-            }
+        if (dht_read(&dev, &temp, &hum) != DHT_OK) {
+            puts("Error reading values");
+            continue;
+        }
 
-            /* split up values into integral and fractional parts for nicer
-             * printing
-             * TODO: this should be done in some kind of library... */
-            int_temp = temp / 10;
-            dec_temp = temp  - (int_temp * 10);
-            int_hum = hum / 10;
-            dec_hum = hum - (int_hum * 10);
+        size_t n = fmt_s16_dfp(temp_s, temp, 1);
+        temp_s[n] = '\0';
+        n = fmt_s16_dfp(hum_s, hum, 1);
+        hum_s[n] = '\0';
 
-            printf("DHT device #%u - ", i);
-            printf("temp: %i.%i°C, ", int_temp, dec_temp);
-            printf("relative humidity: %i.%i%%\n", int_hum, dec_hum);
+        printf("DHT values - temp: %s°C - relative humidity: %s%%\n",
+                temp_s, hum_s);
 
-            xtimer_usleep(2000 * US_PER_MS);
-        }
+        xtimer_usleep(DELAY);
     }
 
     return 0;