Something wrong with the home adapater


So something is going on with my 2.5 ROV. I had everything working, and then I put the internal electronics into the Etube, and everything stopped working.

I checked all connections, and everything looked fine. When I plugged the ethernet and usb on the topside adapter, only the green power light on the cape would work. I pulled off the BBB and hooked it up to my computer with a patch cord and 5v power supply. I was able to open up the cockpit, and view the camera working.

I figured something was wrong with the home adapter on the ROV, and when I pulled it off, all of a sudden the orange light on the cape turned on. At this point, I put the BBB back on the cape (Without the home adapter) and connected the BBB directly to my computer. When I plugged in the USB on the topside (But without an ethernet cord), the cape and BBB powered up, and I had full control in the cockpit.

I'm thinking that there is something wrong with the home adapter - the interesting thing is that the home adapter on the ROV gets quite hot when its plugged in, even though nothing is working. Any thoughts as to what might be happening?



Hi Jesse:

The Homeplug adapters run kind of warm, so that may or may not be an issue. But I'm glad that you seem to have been able to isolate things to the adapters, as this narrows things down considerably.

You can test the adapters step-by-step by looking at the lights on the adapter. There's a power light, an ethernet connect light, and a homeplug connect light- see the plastic shell that you removed the adapter from, or the adapter instructions, if you need clarification.

So what I would try is to take each adapter and test it in series- apply power, apply an Ethernet connection, then attach it to another homeplug adapter- and see that the responses of the LEDs are correct each step of the way.

For your topside box, does the power light come on when you have the USB cable hooked to it? Does the ethernet light come on when you attach an Ethernet patch cord between the topside box and a laptop?

Similarly, pull the BBB off of the Controller board, and attach the homeplug adapter. Hook up the DB-25 connector to the Controller Board so it has a power and tether connection, and then plug your topside box into a USB connection to turn on the ROV. Does the power light turn on on the ROV homeplug adapter? Now turn off power temporarily, install the BBB and attach the small ethernet patch cord between the BBB and the homeplug adapter. Turn power back on via the topside box USB connection. Can you see what happens with the LED lights on the ROV adapter (I don't have one in front of me now, so I don't know what it takes to peek through and get a glimpse of the adapter LEDs)?

Anyway, try these tests and let us know what you find.



So I've been troubleshooting some more, and still I cannot get the home adapter to work.

I've removed the BBB, and it works just fine with a 5v attached. I can log into the cockpit and see the camera. For awhile, if I timed it properly with the cape, I could get control of the servo.

Now however, the cape is not working. Even with the topside adapter not plugged in, the cape power light stays on and makes a buzzing noise. Turning on the topside adapter does nothing on the cape. I'm worried that there is a hardware problem on the cape, and that troubleshooting will not solve the problem, and that I'm better to either fix it, or get a new one. Frustrating to say the least, and I had everything working and ready to go, and now I'm totally stuck.

Any ideas what could be going on? Also, and I imagine it is related, it looks like part Q1 may be fried.


Okay, this is pretty mysterious. Maybe you can post a photo of Q1, but given your symptom that the controller board stays on all the time, it would appear that Q1 is shorted out and allowing battery power to get to the +5V power supply. The thing I can't figure out is how it would happen- Q1 should be pretty bulletproof unless it gets shorted out in some weird way.

Here's one idea that I had- when you put the Homeplug adapter and the BBB onto the controller board, is there clearance between the Homeplug adapter and the BBB? Maybe if the homeplug adapter wasn't pushed in all the way, something shorted out between the adapter and the BBB. We've never had this happen in the lab before, but I suppose it could happen.

Even so, I can't figure out how this would cause a problem with Q1. The input of the +5V switcher is protected by polyfuse F1, so it can't draw enough current to do anything bad to Q1. Similarly, the gate of Q1 is protected by diode D4 from overvoltage conditions. So how can it go bad? I'm scratching my head on this one.

Can you take some close-up photographs of your controller board and post them, or perhaps look around it to see if there are any other components that seem to be burned? I would say just get another controller board, but if we can't figure out what happened to the first one, then there's no guarantee that this wouldn't happen with the second one as well.

Also, I think we're totally out of controller boards until the next production batch arrives in mid-January.

You might also use this opportunity to look around for accidental shorts in the wiring, solder bridges, or anything like that.

You definitely have me stumped on this one.



Hi Walt, Ive gone through everything I can think of. I think what may have happened, is that I shorted something out when I put the electronics into the Etube for the first time.

I'll wait for the Jan. production arrival. Who should I talk to about ordering another one? I can also send mine back, just to see if you guys have better luck. If it ends up working, it could be used for destructive depth testing or something.

Thanks so much for help though,



Hi Jesse:

Send David an E-mail ( I believe), and reference this thread. When the next production lot comes in it will be listed in the store, but if you need a replacement before then maybe David can find a used one kicking around in the lab somewhere. But definitely send back the non-working one. We learn a little something every time something breaks, and perhaps we'll be able to learn something from your board and improve the design or the build instructions in some way.