light sensor without microcontroller

Using Arduino General Electronics
#1

I am looking for a very cheap method into measuring the light in my room and send the data to the computer. Is it possible without a microcontoller ... is there any sensor i can connect directly to the serial port ? Thanks

#2

I’m not out to be a wiseguy, but what’s the market for a cheap light sensor that plugs into a serial port?
Would 1-bit “data” [1 = greater than Threshold] be sufficient?
If you ran a photoresistor to a comparator, and the comparator’s output (0/5V) to your serial port, you’d have your solution.

#3

Thanks for your reply i have very little experience with electronic devices so maybe you can post the actual components i must buy in other to achieve this functionality.

#4

http://home.cogeco.ca/~rpaisley4/Comparators.html

Half-way down the page, see "Photocell circuits"

#5

Note that a standalone AVR microcontroller is about $3, and already has a real serial interface. If the idea behind "no mcrocntroller" is to save money, you're giving up a lot to save very little. Note that a comparator would have to hook up to CTS or similar to be read by the computer, and you'd have to device-control the driver on the computer side to read that.

#6

How do i interface with an AVR microcontroller are there some tutorials

#7

There are lots of tutorials. Look on this web site for example!

You could try this as well: http://tronixstuff.wordpress.com/tutorials/

#8