These are fun projects mostly in the physical world that counterbalance my econometric research. They are mostly related to programming Arduinos or things that go boom or ffffffsssssht.

Flax crackers - Gluten free and low carb

This recipe is for gluten-free and low-carb flax crackers. They are also free from lactose, so you may be wondering if there are any ingredients at all. Yes: ground flax seed, ground almonds, egg, rosemary, salt, water. The difficulty with crackers is how to spread the dough, so read on for a solution. Add some … Read More

Night launch with new launch pad

We improved our previous Gardena-based launch pad by switching to a launch tube design.┬áSince there was plenty of wind, we did not bother flying with a parachute but made a nose cone from a piece of foam which we wrapped in cling film, plus a small piece of play doh at the tip. This worked … Read More

Adventures in etching

This is my very first attempt at etching my own PCBs. My goal was to design a two-sided board to hold four 256K serial EEPROMs (24LC256 Serial I2C EEPROM). The PCB is about 5cm long as you can see from the 0.1″ pitch. The lesson I learned was about using the correct paper to transfer … Read More

Water rocket

Building a water rocket is a great family activity. We used the DLR’s excellent instructions for a water rocket [pdf], a launch pad [pdf] and flight evaluation [pdf] to build and launch our first 1.5L water rocket. We pressurised the rocket to 5 bar and achieved vertical distances of about 40-50m (guesstimated, since all our … Read More

MPL3115A2 Altitude Sensor One Shot Mode

The good people at hobbytronics sell a neat altimeter based on the MPL3115A2 pressure sensor. Its datasheet mentions a one shot mode, which can be a practical solution if one needs a high data acquisition frequency. For some reasons, I did not get the FIFO polling mode to produce new readings at intervals shorter than … Read More

USB-OTG cable for Arduino Uno

Wouldn’t it be nice if you could hook up your Arduino to your Android tablet and use it as a command/debugging interface like ArduinoCommander does? If you want a USB connection instead of bluetooth, however, you will need to find a USB-OTG cable. This is because Android devices usually come with cables that treat those … Read More