Programming – ettis.at

2019-07-202019-11-09

Programming a spiral

As I wrote in my previous post, I decided to program a Custom Shape Generator in Tinkercad in order to be able to generate every detail of my bowl feeder just as I want it to be. I spent my two weeks summer vacation in Italy thinking about sine and cosine, vectors and loops. I implemented the JavaScript code on my cellphone, although characters such as the square brackets [] were a challenge and I needed to install a special Android keyboard app for these. When coming back from Italy it was almost finished, only a few minor details needed to be fixed.

2019-06-192019-11-09

A new project idea!

As chance would have it, I find myself with a lot of spare time over the summer. This screams for a new project! Recently, I have made a list of skills I already possess and skills I would like to learn. So the project that I choose should help me learn a few of these.

After a lot of thinking I came up with the following: I want to make a machine that sorts my perler beads for me!

2018-09-062018-09-07

Predicting periodic events with FFT

Problem description

We have embedded devices periodically sending us data. We want to be alerted as early as possible when a device stops sending data.

A very simple approach is to take the time difference of the last few times a device sent data and calculate the average. When we know a device sends data roughly every 15 minutes, we can easily trigger an alarm if no data arrived for that time.

The above approach assumes devices send data with the same period always. However, that is unfortunately not true for all. We have found devices which never send data during the night. Or devices which stop sending every afternoon, presumably because their GSM internet connection becomes disturbed. Continue reading “Predicting periodic events with FFT”

2013-03-272018-02-18

Weather monitor

The basic idea of the weathermon project is to obtain, record and monitor the weather at my home. All weather data is sent from wireless sensors and then stored in a database, from which different graphs are generated that can be viewed on a PC, over the Internet and on a smartphone. Continue reading “Weather monitor”