title: Wrong temperature/humidity results using SHT11 ZIG001
body: <p>I have an issue in contiki2.7 (I use InstantContiki) using Z1 motes and ZIGLET Z001 (temperature &amp; humidity).
  I tried the code “test-sht11.c” in the directory examples/z1 to get the temperature and the humidity but I have wrong results:</p>
  
  <pre><code>Rime started with address 227.15
  MAC e3:0f:00:00:00:00:00:00 Contiki 2.7 started. Node id is set to 4067.
  CSMA ContikiMAC, channel check rate 8 Hz, radio channel 26
  Starting 'SHT11 test'
  Temperature:   615 degrees Celsius
  Rel. humidity: 2650%
  Temperature:   615 degrees Celsius
  Rel. humidity: 2650%
  </code></pre>
  
  <p>I saw that the I2c drivers had to be disabled (<a href="http://sourceforge.net/p/contiki/mailman/message/29682840/" rel="nofollow">http://sourceforge.net/p/contiki/mailman/message/29682840/</a>) but it still doesn’t work, I have the same results.</p>
  
  <p>Code :</p>
  
  <hr>
  
  <pre><code>#include "contiki.h"
  #include "dev/sht11.h"
  #include &lt;stdio.h&gt;
  
  PROCESS(test_sht11_process, "SHT11 test");
  AUTOSTART_PROCESSES(&amp;test_sht11_process);
  
  PROCESS_THREAD(test_sht11_process, ev, data)
  {
    static struct etimer et;
    static unsigned rh;
  
    PROCESS_BEGIN();
    i2c_disable();
    sht11_init();
  
    for (etimer_set(&amp;et, CLOCK_SECOND);; etimer_reset(&amp;et)) {
      PROCESS_YIELD();
      printf("Temperature:   %u degrees Celsius\n",
      (unsigned) (-39.60 + 0.01 * sht11_temp()));
      rh = sht11_humidity();
      printf("Rel. humidity: %u%%\n",
      (unsigned) (-4 + 0.0405*rh - 2.8e-6*(rh*rh)));
    }
  
    PROCESS_END();
  }
  </code></pre>
  
  <hr>
  
  <p>I'm quite sure it’s not a hardware problem (I tried with different ZIG001 and different Z1 motes).
  Thank you for your help, I'm  desperate…
  Jibus.</p>