Hi,
I have hit a bit of a roadblock with my arduino project and am seeking some advice.
Here is what need help with:
I have two wires that need joining programatically. Any suggestions?
The way I thought it would work is with a 3904 transistor used as a switch....
Any suggestions?
I have two wires that need joining programatically. Any suggestions?
Without knowing more about the wires to be joined (voltage, AC or DC, how high a voltage, current flowing, etc) the only fool proof suggestion is to use a small 5vdc relay and use it's contacts to join your two wires. There are small 5vdc reed relays that can be wired directly to an Arduino output pin. It is generally recommended to wire a reverse biased diode across the relay's coil terminals to protect the Arduino from switching transisents.
So if you have more information avalible on your wires to be joined I'm sure there are other methods.
http://www.allelectronics.com/make-a-store/item/RLY-527/5VDC-DPDT-DIP-RELAY/1.html
Lefty
Retrolefty, thanks for the response.
Here are a couple additional details:
-The device I attempting to interface the Arduino with is a remote. Essentially what I want to do is press a button programatically when specific conditions are met.
-The remote operates on 5v
-The Arduino I am using is a Duemilanove (ATMega328)
Please feel free to ask should you need any additional details!
Well without a wiring diagram of the remote it's kind of hard to recommend anything other then the relay solution I already posted.
Lefty
A remote what??? 
A Bluetooth Playstation 3 remote.
I have determined the following:
There is a 4.40kohm resistance between the two wires. When the micro controller detects =< 110ohm resistance between the two, it interprets it as a press. (I hope that made SOME sense :P)
Even more interesting would be to measure the voltage on one wire relative to the other when pressed and not pressed.
If you measured resistance while the remote was on, you're kinda fooling yourself as it doesn't mean anything. If you measured resistance while the remote was off...it still doesn't really mean anything.
Measure the voltages.
Unpressed: 44.7 mV
Pressed: 1.5 mV
Sounds unlikely.
Was the remote on?
Yep, the remote was powered on and paired to a PS3. I checked the voltages multiple times to make sure as they looked a bit strange...
Here is another tidbit of information:
One of the wires is a common between two buttons. So, there are three points total: right, common and left. I need the common and right to connect programmatically.
Really strange.
What normally connects those wires together? Just a mechanical button?
Which wire has the higher potential, the center or the right/left? In other words, where was your "black lead" and where was your "red lead" when you took your voltage measurements?
My positive lead (red) was on the common, with the negative lead (black) on the right. When I reverse them, I get the same result on the negatives :-?.
In addition, the two wires are not just connected to a normal mechanical button, but rather to a force sensor.
Do you by any chance have your DMM set to measure AC voltage instead of DC voltage? (please say yes please say yes please say yes....)
Haha. Nope, its on DC voltage.
By the time I edited my reply, you had already posted yours;
The object to which the two points are connected to is a force sensor.
I think I got it:
The force sensor returns a result between 1.5mV and 44.7mV proportional to the amount of force applied....does that seem correct?
Oh!!!! Well then I'm going to guess that your measurement of resistance (with the power OFF) is a good model for what's going on.
A small reed relay in series with a 110 ohm resistor would be a good way to simulate the force sensor.
Sweet! Thanks for all your help!
And yes, the power was OFF when I took those readings.
Now, how would I use a reed relay with an Arduino, and is there any specific one I should use...?
This would be my recommendation, using a Hamlin 5V reed relay (HE3621A0510):
Nice! Thanks a bunch!
These are the ones
right?
Right.