Monday, October 6, 2008

Hello again!

The door bell project is working in full swing! although not many people seem to ring project: detect bangs from people using the door knock.

On another note, I got my wife a small tablet (wacom bamboo) and it is really nice! to celebrate, I decided to make a handmade schematic of my circuit to read the electricity meter. So here it is on the right. On the bottom is the LDR which has a value of about 20K ohm when in the dark and goes down to 200 or less in bright light. So I get the little LDR, which is about 3mm in diameter right in front of the blinking led on my new digital electric meter and every time it blinks the input of the arduino goes down, signaling one watthour having been consumed. The Arduino then communicates that to the computer which dumps the time into a database, from which I can then generate graphics and check consumption.
On the next post, and to try to improve my tablet skills, I'll describe the circuit used to read the gas meter.

Furthermore, I just got a new Arduino today, the Diecimila, ordered by Joao, so I'll try to get the thermometer and other environment variables going.

1 comment:

João Silva said...

Nice schematic! I'm considering buying a tablet, it must be so much faster from idea to "computer screen"...