PC to control LED brightness

[BS]

Hi,

Anyone know how to use PC to control LED brightness? Example, the PC can control the LED brightness from 100% (most brightness) to 0% (off)!

If anyone know pls reply me!

Thanks!!

 

[drwho78]

You can always use the PC's printer port to drive the LED. Use a current limiting resistor on each of the 8 data bits and sum the output to drive the LED. Then the brightness of the LED is set by the 8-bit word that you write out. At 00H, the LED is off, and at FFH, the LED is at full brightness.

 

[Bluechem]

you can use pwm with a microcontroller connected to computer serial port, see
https://www.iguanalabs.com/pwm.htm

 

[aamiralikhoja]

use paralel port to lit led's
visit the following page for more information
http://www.linuxfocus.org/common/src/article258/ref/
thanks aamir

 

[dunn]

Use the PC port to pulse the led.

Control the mark:space ratio to control the brightness

OR

Use the PC port with a D to A converter (but check that the converter can source/sink the required current first).

 

[TRUNGDPHAN]

you can combine Microcontroller & DAC to control LED through LPT/COM port.

 

[electro]

Hi BS,

Take a look at: h**p://www.electronics-lab.com/projects/pc/021/index.html

* -> t

"8 Channel software controlled fanbus with PWM"

Regards,

 

[aryajur]

The best and most robust way would be to use a DAC, which can be assembled using an opamp and a handful of resistors, that will give you 256 levels of brightness. Also if you want to drive a higher load say 2 or more LEDs and the opamp cannot support it you can use a power transistor to supply the LED current.
I have attached the opamp DAC schematic.