interfacing with micro

[Eng.Mina]

hiii
what's types which can interface N led's to one pin of micro controller (atmega xx) or (picxxx) ?
thx.

 

[alexan_e]

Your question is not very clear , what do you mean?
What is a N led and what do you mean by types?

 

[Eng.Mina]

i need for example to connect 8 leds in parallel and are controled from 1 pin from micro controller

 

[alexan_e]

Use a NPN transistor, drive the base with a resistor , emitter to ground, led cathodes to the collector and the anodes through resistors to the positive supply.

Alex

 

[paulfjujo]

hello
it will be difficult with only one pin of microcontroller !

Maybe you can search on the web One Wire bus system ..

but with 2 pins, you can use I2C interface (2 pins: SDA SCL) or SPI interface mode
with one MSP23017 to drive 8 or 16 outputs .. and add a buffer like ULN2083 for more current in leds.

 

[Eng.Mina]

thx Alex ur circuit is easy
but the number of transistor (npn) and it's current .



paulfjujo thx 4 ur replay but need to explain ur idea more
if can put some circuit's

 

[alexan_e]

I think I misunderstood what you asked.
You can use shift resisters like 74HC595, take a look at
https://mbed.org/cookbook/1-wire-shifting-2x16-LCD
www.romanblack.com/shift1.htm