DVDdoug:
You can use a transistor or MOSFET to "boost" the current. [u]Here is an example[/u] of a MOSFET driving a motor. (You'd need a current-limiting resistor and you can use your existing 5V power supply, and since you're not driving a motor you can leave-out the "protection diode" D1 .)
[u]Here's and example[/u] using a transistor to drive a solenoid.
Do you know how to calculate the current limiting resistor? You might try it at 30 or 40mA first. That might be enough. And during project development, it would be a good idea to try it at low power and short distance anyway.
It's just like sending serial data (RS-232, etc.). You should be able to find some examples, but depending on what you're controlling you may have to capture/record transmissions from the existing transmitter in order to figure-out the codes.
DVDdoug:
You can use a transistor or MOSFET to "boost" the current. [u]Here is an example[/u] of a MOSFET driving a motor. (You'd need a current-limiting resistor and you can use your existing 5V power supply, and since you're not driving a motor you can leave-out the "protection diode" D1 .)
[u]Here's and example[/u] using a transistor to drive a solenoid.
Do you know how to calculate the current limiting resistor? You might try it at 30 or 40mA first. That might be enough. And during project development, it would be a good idea to try it at low power and short distance anyway.
It's just like sending serial data (RS-232, etc.). You should be able to find some examples, but depending on what you're controlling you may have to capture/record transmissions from the existing transmitter in order to figure-out the codes.
Wow, this MOSFET thing is really confusing, I looked for it in google, I'm still confuse... And about sending IR codes, that's ok, I'm already sending codes to my TV (It's working fine but I want more power on led !!!)
The thing what I was thinking was: Use a 9v 2A supply to supply arduino and 2 rows ( + and - ) of breadboard, the arduino only consumes 1A, the excess would go to my breadboard which should supply a LCD (90mA) which have a simple conection (positive,negative, rx, tx pins) [positive and negative should direcly to external power [with resistors to get 5v]) and supply 4 IR LEDs (0,4A total) but the problem is how to do this LED power supply, the question is, MOSFET, I can only use it with Arduino 5v pin or can I use with an external power supply?
INTP:
If that is all you are doing, you can still use just the Arduino.
Use an NPN transistor as a switch. LED will have access to more current from the 5v line, and you will still control it just the same with the IO pin.
The problem is: I'll have a tons of sensors connected into my arduino, light sensor, rf emissor, rf receptor, presence sensor.................. They will use a good current, that's why I wanna supply the LED with an external supply