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Topic: Sudden unreliability with my network-enabled Arduino project (Read 8 times) previous topic - next topic


Florescent lights do emit a RF signal that could possibly be harmful. Does your networking cable run near these lights? I am a amateur radio operator and i know that the ballast in those lights can cause audible noise on certain frequencies.... but will also create unwanted "noise" in data cables.


Definitely run it off a battery, assuming you have one that will last several days. Clean power is important.

I haven't looked at your code but have you checked for memory leaks? If you use the String functions you might be leaking memory. There are sample code snippets out there that you can drop in to report free memory. That might help with debugging.

Connect it up to a serial monitor (eg laptop) and get it to send you diag info regularly. Make it print out the value of one of your variables at regular time intervals. Note what happens when you send it a failed command. Does the output pause? Does the value of that variable make sense?

Checking for humidity: if you can't measure humidity easily, package your board up into a plastic box, sealed as best you can, and put a packet of Do Not Eat in there to absorb as much moisture as possible.

Since you have apparently had it working in the garage for up to five days, the fact it seemed to work fine in your room is not to be trusted. The fault is so intermittent that you'd need to run it for several weeks before you can be reasonably sure it is ok.


Shown below is my device, installed in my permanent location, and circled in red. Also notice the 3 fluorescent lights, which I believe is on the same circuit.

This image shows where the Ethernet cable crosses the electrical cable for the lights. I've always understood that as long as they cross like this (are perpendicular), it's ok...you just never want to have them running in parallel.

I currently have it connected to an extension cord (orange, hanging down) which as I mentioned in a previous post, goes to inside my house, and it works fine when connected like this. However, when I have it plugged into the black power strip (where I want it to be plugged in long-term/permanently), I have the problem previously mentioned.

Anyway, in answer to your question, dswan75, the ethernet cable does run within a couple of feet of the middle lights, but I don't know if it's an 'air'/'airwave' problem...it seems to be inside the actual electrical lines themselves that's going into the power of my device wouldn't it? Because again, that ethernet cable never moves through my testing.

@Hugepedlar - I don't know if I have a battery that could power it for very long...a 9V wouldn't last very long, would it?

I don't know how to check for memory leaks yet. I still tend to think it's a hardware issue, but I will look into it. Yeah, I've been thinking of hooking it up to the Arduino serial monitor, but have been putting it off as I will have to modify the circuit in order to be able to do that I think.

I'll see if I can find something like that to put the project in.

Well when I had it in my room, it did work for weeks if I remember right. And when I have the device in the garage, and the power running to inside the house (in my room specifically), it worked for weeks also.

Thanks everyone so far...maybe the pictures will reveal something I'm missing...


See http://makeprojects.com/Project/Instant+AC+Power+Filtering/2922/1 for a quick way to filter your power supply. If it's a power problem, that should fix it.


Looking at the picture the screw heads that you used may be shorting traces on the circuit board. This would have taken time to wear through the silk screen . remove the screws and use a wire tie ( or plastic stand offs ) to hold the board and re-test. if it works reliably , you can use plastic standoffs to fasten the board securely. I use #4-40 standoffs with a small #4 lock washer and the screw heads don't touch any traces on the board.

Hope this helps !

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