Hey folks, this is my first post here on the forum.
I have a arduino duemilanove and I must to do the following, basically I have to close a circuit remotely, and at the moment I have a Futaba RC system with a servo connected to the receiver that pushes a button that then powers a 12v relay. What I want to do now it eliminate the servo using the arduino.
In other words I want to connect the servo output on the receiver to the arduino and with the arduino, determine wich output port it must power, then connect a n-mosfet to that port to power the relay.
I am not very experienced with the arduino so if you guys could help me I will be very thankful
The output is easy. Use a resistor of 1k from the Arduino to the gate of a "logic level" power mosfet. It must be "logic level" so it will turn on with a voltage of 5V. Almost every "logic level" power mosfet on Ebay will do. You also need a protection diode over the relay: Arduino Forum
Yes, it has a normal output, (+5v, 0v, signal). In theory I think I only need the 0v and signal wires.
I want the receiver to read the incoming signal that would normally go to the servo and then decide what to do, i.e. above 1.7ms output to pin x, under 1.2ms output to pin y
Thanks Krodal, those links describe exactly what I need. Just one think though, the diode I am meant to use on the relay, is the ideia to connect it in parallel with the coil opossing the current so that when the relay turns off, the induction shorts itself through the diode? Is it worth connecting a capacitor to absorb the current?
Yes, that's exactly what the diode is for.
You cannot use a capacitor in parallel with the coil. Or do mean a 100nf + 100 ohm to reduce sparks (is that called a snubber circuit ?), but that is no good for a mosfet or transistor. Just use the diode for the coil and capacitors for the power supply.
