Tech insights

Recently BESCOM increased their tariff. But there is no improvement in reliability. This forced me to look for alternatives. Inverter was the obvious choice. But the engineer in me is worried about the electricity wastage. Inverter has around 90% cycle efficiency. There is wastage in charging the battery and converting it into AC power. What if the power supplied was free? That's where Solar power comes in. Components of a Solar system Photo-voltaic (PV) cells Charge controller/ Conditioning Unit/ CCU Battery Inverter There are numerous articles talking in depth about each of these. So I'll just list down the most important things to keep in mind. PV cells are available in mono and poly crystalline models. Mono crystalline is more efficient and hence costs a premium. One can start with a single panel and add more over time as necessary. Less number of panels or less power panel will only increase the charging time. Latest in CCU is Maximum Peak Power Tracking ...

Mahesh Murthy recently  tweeted : Now a proud owner of Audi R8, Tesla S & Ferrari 308. Found this from Google Play: my 2-yr old bought them on Asphalt 8 This might sound like a pardonable innocent act; some might find it cute too. But your HomeOS doing the same - analyzing a vacant parking space in your car, a certain amount of bank balance, based on car your neighbour recently bought, the car pic your cousin recently posted on FB or some darn algorithm that the developer in Google, Apple or MS came up with - can be a terrible nightmare, possibly even leading to a lawsuit. Companies are already shirking off their responsibility blaming the algorithm creating a scene of mistrust with customers. The recent issues with  Uber  is a case in point: We are not setting the price. The market is setting the price. We have algorithms to determine what that market is. My point is IoT is never going to be a master decision maker. At b...

Mood lighting or ambience lighting refers to using different colors of light to create an ambience reflecting a particular mood. With incandescent or CFL bulbs, mood lighting was very restrictive - color of the light would be restricted to the color of the enclosure of the bulb. However advent of RGB (Red Green Blue) LEDs has opened up a new dimension in mood lighting. A good example is Philips Hue (http://www2.meethue.com/en-xx/). Not only one is not restricted by the color of the enclosure, one gets a choice of colors not previously possible which can be dynamically changed too!! If you don't want to invest in a proprietary solution, here's one way to achieve the same using RGB LED strip and RPi. Hardware A typical RGB strip needs 12V. However, RPi provides only 3.3V at the GPIO pins. Hence we need a bridge between these two circuits. A ULN2803 chip acts as this bridge - it takes TTL input and allows one to drive a high voltage circuit. Software We ...