light sensor device

Hey i was playing splintercell and i saw the light detector display i thought of how to make one but got no ideas.
does anyone know how to make a sensor so that there are three leds red orange and green.in darkness the green will be on when it gets brighter it will turn to orange and wheneven brighter like infront of a flashlight it will turnt to red. thanks.

colin886 said:

Hey i was playing splintercell and i saw the light detector display i thought of how to make one but got no ideas.
does anyone know how to make a sensor so that there are three leds red orange and green.in darkness the green will be on when it gets brighter it will turn to orange and wheneven brighter like infront of a flashlight it will turnt to red. thanks.

Click to expand...

A site called "All About Electronics" (correct the name if it is wrong) has a section on ADC circuits that contained a DAC in them.

Make yourself one, and add some logic gates at the output of the count.

For example, a dark light could produce a digital output of 0000, and a bright light could produce a 1110, and medium light could produce a 1001.

Take the output and pass it through a decoder. If you only need a 3-bit resolution, you can use a 74xx138 decoder.

The higher the resolution, the better chances a particular brightness can be detected, but more resistors will be required. 8-bit is common.

Try using national's LM3914-LM3916 dot/bar graph display ICs. Set for dot display.

does anyone have a schematic im not very good with creating/desining stuff
:?

colin886 said:

does anyone have a schematic im not very good with creating/desining stuff
:?

Click to expand...

download the datasheet @
**broken link removed**
it has example ckts given