Arduino act as I/O switch on other circuit

Hi people!

I need some help here. I am currently trying to hack my RC car's remote with my Arduino to make it drivable thru the PC.

The remote's buttons are simple I/O switches same as reset button on Duemilanove. (Left, Right, Up & Down - 4 switches)

I want to remove these switches and make the Arduino act as switches to control it. This is to prevent screwing up the remote controller's circuit board.

If anyone has any tips or help on this subject, feel free!


a) read about optocouplers. That could work, if the voltagedrop on them is not to high....

b) Other possibility: Read out the remotes voltage on the switches. Hope, that it is 5V like your arduino. And give the 5V directly from the arduino. (And connect their grounds)

c) Get servos, and let them press the buttons ::)

Another possible solution is to use 5vdc low current relays. These relays can be driven directly from the Arduino output pins, however it's still a good idea to wire reverse biased diodes right across the relay coil terminals to suppress transisents. The relay's contact terminals can then wire directly across the existing switch contacts.