Exponential smoothing in Python

The problem

While measuring temperature using my Arduino and a TMP36, I found that the temperature reading fluctuated wildly. After reading up a little, it became clear that since the Arduino’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.

Networking monitoring with a RaspberryPI

A while back my house mates and I found that our internet connection was terribly slow in the evenings.

I decided to use my newly arrived Raspberry Pi to write some monitoring tools to see what the pattern was and how bad it was. This way we would also have something to give to Virgin Media to show there was a problem. At the same time, I had been wanting to write some software to push data into the graphing system Graphite, so this seemed like a good time to do that.