Saturday, March 26, 2016

Repurposing an old Android Phone

I had an old Samsung Galaxy Y (GT-S5360) which the previous user didn't particularly enjoy for its performance and replaced with a fancier, newer model. With no obvious use to give to the device, I decided to repurpose it for building some kind of a remote monitoring/observation station, and try to find out how it stands out against the harsh outside environment.

While not attempting to simply put the device outside, directly exposed to the sun, rain and extremes of temperature, I made several customizations to better prepare the smartphone turned into a monitoring station.

The first thing I wanted was to have it entirely self-sustainable. As such I bought a 10 watt photovoltaic panel to harvest the energy required by the device:

Thursday, April 2, 2015

Drone Recovery Parachute

Failure is a concern that is always present in the operation of a drone. Given the continued increase in acquisition and use of these devices by the general public, safety is of paramount importance. Even the smaller devices of about 2 kg of total weight, in case of total failure at altitude, will fall like a brick and cause damage to whatever is below.

Most configurations such as quadcopters, don't offer any intrinsic redundancy (in spite of having 4 motors). The failure of a single motor will prevent the quadcopter of maintaining level and yaw-locked flight. Some enhanced control algorithms are being developed to provide level and controlled descent in case of single motor failure. Naturally, yaw control is lost, but the on-board inertial sensors and magnetometer are capable of keeping track of the orientation, therefore knowing how to distribute throttle by the surviving motors.

Monday, March 30, 2015

More UV light photography

It is interesting to discover in everyday objects, the specific fluorescence of each one. The particular wavelength (i.e. color) of visible light which is irradiated depends on the characteristics of the substance illuminated by the ultraviolet light. As such a very interesting combination of colors can occur, depending on the varieties of materials the object has. The following dolls is an example: