i want to drive some leds via parallel port of my computer.
Does anybody knows a got ic, where i can send via (eg hex commands) parallel prt commands to drive different leds. Each command drives another led
I am quite interested in your topic..Could you post the schematic? I have done microcontroller interfacing to 7-segment led display n control using assembly language...I feel like want to try control through my pc...how? Can teach me...Thanks
dears
i hope that all of you take this advise from me
i work to control adot matrix display
its consists at least 6400 led
and realy i succsed in controling it with agood lighting
but i used aver cheap and very high out put with very low input
is called the OPTOCOUPLER (4n25)
Yo dude,i've just registered to this site and i found lots of interesting stuff. May be i can help you for this problem
For a small number of LED maybe you can use the pin dedicated on parallel port. The port it itself can drive enough current for one led (approx. 20mA) current. But still you need series resistance to limit it (220Ω). But if you want to get a precise value try to calculate it with some of kirchoff laws, not forgetting the voltage for the LED and its forward current.
If you want more safety circuit for your computer, just use some of optoisolator/optocoupler (TLP524 series) and it will protect your PC from various voltage surge hazards.
if you want to control lots of LED just use some extension device (8255 PPI IC for example) or try to use a serial to parrarel converter (HEF4094) which can be cascaded for more parrale data needed and you just need 3 line control from your parrarel port (for Clock, Data, and strobe) Even you can use combination for the circuit to get faster data transfer.
if you want a circuit just hit me at jal_rule@yahoo.com and i'll try to hit you back. just tell me the circuit specification you need.