I want to fire a camera with R/C. I know the switch w/relay works but wanted something smaller quieter. Would the R/C switch with digital output work it basically just needs to ground 2 leads coming from the camera. My electrical knowledge is limited so keep it simple I’m learning 
I cannot say which switch would be most appropriate without knowing more about what you are trying to switch and how much current you need to sink. The Pololu RC Switch with Digital Output would be appropriate if you just need to connect part of your circuit to a logical high or low voltage. For currents of 3A or less you could use our Pololu RC Switch with Small Low-Side MOSFET. If your current is between 3A and 15A you could use our Pololu RC Switch with Medium Low-Side MOSFET.
-Derrill
It’s pretty simple off the digital camera 2 leads need to be connected so I have used relays which work fine but perhaps overkill for the task. I’m sure there is some voltage running thru but it’s miniscule so the 10 amp relay is overkill. So basically I need a switch that will contact those wires together for a brief moment to fire the camera. So basically a simple switch normally open closed when activated. Will any of the other r/c switched do that?
Hello.
The Pololu RC Switch with Digital Output seems like it might not be appropriate for your application. The RC switches with low-side MOSFET referred to in my last post might work for you, but you will need to connect them in the correct direction. If you are having difficulty figuring out how to connect it after having read the product pages, please post a schematic of your setup, and I might be able to help you further.
-Derrill
Ok so if I understand correctly? since I’m not actually applying power to the device just need to short the wires from the shutter cord. I should jumper across the “load power supply” connections and attach my leads from the camera to the “load” contacts? 
That does not sound like the correct way to wire the switch. If you can post a schematic, I can try to help you make the proper connections.
-Derrill
I think this is getting made harder than it probably is. There is no schematic to show. There are 2 wires coming from the camera that measure 2.4 DC volts .22 milliamps. When they touch they fire the camera. I simply wish to connect them using a R/C switch. So I just need it to act as a R/C switch for the very low load in those wires.
Your mosfet “switches” seem to be designed around delivering power and if I understand represent something similar to a normally open dpdt relay. I don’t need to put power in the system it has it’s own I just need to connect 2 wires like a simple switch. This is why I thought jumping the load power supply terminals would make the Pololu RC Switch with Small Low-Side MOSFET act more like a basic switch??
The way the RC switch works is more complicated that just connecting two wires. One side of our switch is grounded, which will probably make a difference in how you connect it in your circuit. If you do not want to have to deal with these connection issues, I suggest sticking with the relay solution you have.
-Derrill
Different cameras have very different ways of tripping the shutter, some won’t allow the camera to take an image if it’s not in focus, though that can sometimes be turned off in the setup menu.
If it is just a case of switching close to 0V, and it usually is, a simple NPN transistor with a 22K to 47K resistor to the base and connected to a pin, the Collector wired to the +ve wire from the camera and the Emitter to 0V will work. Send the pin high, the transistor will conduct and the Collector to Emitter will go low resistance, it will still be 0.6V above 0V, but that is usually enough, in my experience as long as the Collector is below 1V when conducting it will trigger the camera, though it does depend on the camera. Panasonic cameras require a specific Voltage on the trigger circuit, too high and the camera will just auto focus, too low and the camera will do nothing for instance.
Any general purpose NPN transistor will work on most cameras, I use a 2N2222.
The circuit is, a 22K to 47K resistor connected to the Pin you want to use, the other end of the resistor to Base, the Emitter to 0V, the collector to the +ve wire from the camera. The 0V from the camera as well as the transistor Emitter will need connecting to 0V on the processor board too.