https://www.rawmeat.org/tags/observability/ Recent content in Observability on rawmeat.org Hugo en-us Wed, 12 Feb 2014 20:38:00 +0000 https://www.rawmeat.org/code/python-exponential-smoothing/ Wed, 12 Feb 2014 20:38:00 +0000 https://www.rawmeat.org/code/python-exponential-smoothing/ <h2 id="the-problem">The problem</h2> <p>While measuring temperature using my Arduino and a <a href="https://www.sparkfun.com/products/10988">TMP36</a>, I found that the temperature reading fluctuated wildly. After reading up a little, it became clear that since the Arduino&rsquo;s analog pin measures discrete values of 0-1023, and the voltage varies between 0-5V, the smallest difference that can be detected is ca. 4.9mV. For the TMP36, a temperature change of 1°C triggers a voltage change of 10mV, so the smallest temperature increment that can be registered is ±0.5°C. For additional fun, the sensor is only accurate to ±2°C, so plenty of opportunities for sensor fluctuations.</p>