Did a refresher course on HTML and CSS – in case I need it again.
I need to practice on positioning using CSS
Archive for March, 2014
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Opened up an electronic energy meter (single phase) to see what is inside. Unfortunately the meter had a protective circuit for tampering and it stopped working once its cover was opened.
Don’t have a camera to post the pics………..but will take pics and post tomorrow.
This is rendering of the design for the USB Tiny ISP programmer that I earlier made and tested manually. This design is for fabrication purpose. Hope to order it and get it checked soon. One of our first kits.
TOP VIEW
OpenHware USB Tiny ISP Programmer
BOTTOM VIEW
OpenHware UsbTiny ISP Programmer
LED is a PN junction diode. And a PN junction diode when inverted acts as a small capacitance. This property can be used to make LED also behave as a touch sensor – sensitive to human touch. All you need to do is invert the led – charge the capacitance – and measure how long does it take for the capacitance to discharge. Ordinarily it would take some time for the capacitance to discharge – but when you touch the negative lead (+ve end of the led as capacitor) of the LED, our body acts a charge sink and the capacitance discharges quickly. Here is the algorithm: 
//Discharge any capacitance remaining on the LED Set LeadA Output HIGH Set LeadB Ouptut LOW wait 1ms //Reverse Bias and charge Set LeadA Output LOW Set LeadB Output HIGH wait 1ms //Discharge the capacitance Set Lead B Input LOW Count how long it takes for the LeadB to read low
Attached is the arduino Code for this:
ledAsTouchSensor.ino
Man and the Machine 