Standalone Arduino Serial Communication

Hello,

I am trying to design a remote control system, very basic on off stuff, using an arduino uno. The problem I am having is that I can easily send serial data out and receive serial data in when the arduino is connected to the computer, however if I power it with a batter pack instead of the computer I am no longer able to sense or transmit data with that arduino. I'm sure there is something simple I'm over looking. Any thoughts??

Thanks,
Zach Njus

It would be nice if you give us more details. To what device are you trying to communicate serially?

What are you talking to and how have you got them connected?

Do you have the grounds connected, it's possible that when using USB you are getting a de-facto ground through the computer.


Rob

Alright yea I was pretty vague in my first post, sorry about that.

How I want them connected is to have one arduino set in a seperate room of my apartment just running code looking for a particular set of data. The other will be connected to my computer for now and will transmit whatever I type into the serial monitor.

The one connected to the computer will be powered by the computer through the programming cable and the second one in the other room will be powered by a 9V battery pack, I don't have any special wiring going on here, just the battery pack plugged into the power port of the arduino.

Right now I have them hooked up as is shown in this tutorial http://www.sparkfun.com/datasheets/RF/KLP_Walkthrough.pdf

I hope this is a little clearer.

So that's two posts now and not once have you mentioned the small detail that you are using wireless, I still don't know for sure, I had to download a PDF that is about wireless and I'm now making that assumption.

So what else is there, when the Arduino is on the computer is that the same computer that the other Arduino is connected to?
When it's on batteries is it in the other room or are they next to each other? Have you tried both?
Have you tried the exact same setup (ie on batteries) but using wires instead of the modules?
What current do these modules draw? Are the batteries up to the job?

We are not clairvoyant.


Rob

You were very vague from the beginning. You didn't even tell us that you were using a wireless transmitter and receiver. I downloaded the pdf and understood what's going on. Now about your problem. Did you connect all the pins correctly? Are the receiver and transmitter in range. Try using an antenna and also place them beside each other and see if it works. If it works them it is range problem. If it still doesn't work then it is something wrong with the connection or the parts are not working. If it turns out to be problem with range then try using an antenna with the antenna pins. I also read something about tuning the parts. Also try powering the transmitter directly from the batteries instead of the ardino. This increases the singnal strength from what I read in the datasheet. Also try using 6 AA batteries instead of a 9 volt battery. 9 volt batteries are expensive and last less than 6 AA batteries. Hope this helps. Also try not to be so vague in your next posts.