Electronics FAQ

I am an electronics engineer and I live in Mumbai. Atleast I used to, until I shifted to Pune, but since my parents live there, I visit Mumbai very often. Of the major cities I have been to - Mumbai, Delhi, Bengaluru, Chennai, Pune - I find Pune's climate among the most pleasant of them all. Bengaluru's would have been comparable had it not been for the pollution. Mumbai (and Chennai's) humidity levels are always unbearable to humans as well as machines. No matter how well you design a machine, it will always die out a lot earlier in Mumbai as compared to its exact same counterpart put to use in a dry city like Pune. No wonder cars used in Mumbai have a lesser resale value - who wants a second hand car which has been tortured by humidity for many years! I am a fan of mechanisms. The word mechanism has two definitions: A system of parts working together in a machine; a piece of machinery. A natural or established process by which something takes place or is brought about.   ...

NOTE: This method is not at all reliable. cron jobs work better than startup scripts. But it seems that the cron implementation in DD-WRT is broken. So I switched to using TP-LINK router which happily run the more sturdy OpenWRT. OpenWRT handles cron jobs very reliably, look at my newer blog post on how to configure a router running OpenWRT to login to your Reliance Broadband automatically - this new method using cron has proved to be quite successful for me. ---Introduction, skip this if you already know what you are here for You reach home after a long day at office and are looking forward to catch up with friends on facebook. You weren't able to do so at office 'coz the internet there is terribly restricted and you have recently cancelled the 3G data plan on your cell phone. You turn on the WiFi router and wake up your laptop from sleep mode and this message pops up!! So the first webpage you are forced to visit is your Internet Service Provider's to login to yo...

A Tutorial on various kind of Piezoelectric transducers from Open Music Labs: http://www.openmusiclabs.com/learning/sensors/piezos/

'Coz I keep forgetting the directions of the RS232 signals all the time.

This is what happens when you plug in a AC/DC adapter meant for mains input of 110VAC/60Hz (USA/Japan) into a 230VAC/50Hz (India). AC/DC adapter is a simple Stepdown Transformer > Bridge Rectifier > Capacitor type. You can see from the pictures that the windings on the primary side heated up and melted and shorted out. The heat also caused some insulation to melt and ooze out of the transformer.  It seems the wall wart (colloquial for AC/DC Adapters) has grown warts of its own! Hemorrhoids even!!

Here is a video of a PWM signals generated using a microcontroller. The two signals are in quadrature phase - i.e. their phase difference is 1/4 of their period (or you can say they are 90 degrees apart). The signals were generated using an ATmega32. Program was written in Assembly Language. AVRStudio4 and STK500 were used as development tools.

We have a Maruti Swift VXI which has a K series engine. Here's a photo of the  OBDII connector  located on the left inside of the dashboard panel under the steering wheel. Do not yet know what all one can do with it.