In 2012, sadly my father in law passed away. He was a very good friend and fellow electronics enthusiast. Between the immense amount of electronics parts he left us, I found some ZM1000 Nixie tubes in perfect condition. In addition, there were classic 74141 Nixie drivers. This gave me the inspiration to build a Nixie tube clock, dedicated to him.

My friend Joep, whom I've known for almost my whole life, has always been a real music freak. He used to DJ at parties of friends and class mates using his own turntables, audio set, and disco lights. Since there were a lot of lights, it was always a heck of a job setting everything up. To solve this problem, we integrated all effects lighting he owned into two giant 'discobakken' (disco boxes, literally). When he got married, I gave him small scale exact models of these light effect units. Read on to see how they came out ...

Water activity? And why would I want to measure it? Food always contains a certain amount of 'free' or unbound water. The more unbound water is present, the easier it is for micro-organisms like fungi to grow. Hence, the shelf life of food products is shortened by the presence of unbound water. Water activity is a physical quantity that describes the amount of unbound water in a product. Therefore, by measuring the water activity, you can estimate the shelf life of food. Only problem is the incredible amount of money you have to pay for a commercial water activity meter. In this article I describe an easy and cheap water activity meter on the basis of a humidity sensor, an NTC, and an Arduino Pro Mini.

Recently, I managed to get my hands on an old Haake thermostat bath. My company decided to part with it after the heater had kicked the bucket. Fortunately, I discovered that only the heater control relay was broken, so salvaging the thermostat would be a piece of cake. So much for the thermostat, but what about the control unit? I could not get one from my employer, so I made one myself on the basis of an Arduino Pro Mini. In this article I explain how I did it.