Did I damage my little Arduino flight controller? :( - Page 1
Forum section: electronics / beginners

author: niblnabl
author_rank: Newbie
timestamp: April 12, 2015, 06:25:45 pm
content: I'm not sure if I should be asking you guys or an RC community, but I think I'll get the right answer (hopefully!) here.The device is an AlienWii, a hard to get experimental brushed Arduino flight controller board for a micro quadcopter that runs off of a 1S LiPo battery, and I can't get my mind off of this because I take very good care of my things.A link to the board:http://micro-motor-warehouse.com/products/alien-fcConnected to it are:four 7x20mm brushed coreless motorshttp://micro-motor-warehouse.com/collections/7mm-custom-builds/products/cl-0720-14+Lemon Rx DSM2 satellite receiverhttp://www.lemon-rx.com/shop/index.php?route=product/product&product_id=98So here's the mistake I made: I had the quadcopter plugged into a USB 3.0 port on my PC but not the battery, and while it was connected to the PC via micro USB, I armed the board and gave the motors throttle (for tuning purposes). I don't recall if the board had any hiccups the first time I did it. I have since used it many times and had no issues. However today I did it again, I had it running for about 3-4 seconds on about 30% throttle and it froze the "MultiWiiConf" program that is used to configure it via a PC. Stupid me, I went and did it AGAIN, and it froze a second time, and one of the LEDs on the board dimmed for a moment. That is when I did some digging and found that I shouldn't be doing this.So my worry comes from the fact that the board and motors are designed to run off of a 1S (3.7v nominal) LiPo battery, and is to be configured via the 5v micro USB port, but is not (according to the guy who distributes these boards, but does not assemble or design them) to be powering these motors off of the USB port. I wish there was a warning somewhere. So with my very limited understanding of these components, I think I may have damaged the Mosfets or some other components? The board still works so far, but I'm not even getting close to pushing it like the 8.5mm motors I want to put on it in the future. Also, I'm not worried about damage to my computer, and I understand that those freezes could have been from the drop in voltage due to the USB port being unable to deliver enough amps.Thanks to anyone who helps me find peace of mind, this is just one of those things that sits in the back of my mind. I love the cute little thing.Pictures for fun or reference:

author: Simon
author_rank: Unknown
timestamp: April 12, 2015, 06:29:59 pm
content: does it still work on the battery ? does sound like short circuit protection went into action on the pc

author: niblnabl
author_rank: Newbie
timestamp: April 12, 2015, 06:38:32 pm
content: Quote from: Simon on April 12, 2015, 06:29:59 pmIndeed, it appears to be fully functional but I can't take it outside and really push it at the moment because of the weather.

author: Simon
author_rank: Unknown
timestamp: April 12, 2015, 06:49:22 pm
content: Well it sounds like the port throttled the current back which would have cause the voltage to sag and so probably cause communication problems with the PC due to fluctuating voltages so it's probably ok.

author: niblnabl
author_rank: Newbie
timestamp: April 12, 2015, 06:57:14 pm
content: That makes me feel a bit better, so those little SMD components likely wouldn't have taken any damage from extra volt or so? I don't have much understanding of circuitry and what not yet, for all I know the components driving the motors are always getting 5v when it's connected via USB. When you're configuring this board, doing what I did is as simple as flipping a switch and giving throttle, because you already have your controller bound and communicating with the software for tuning purposes. It would kind of surprise me that it could be that simple to damage it.Heres one of the posts that scared me:http://www.rcgroups.com/forums/showpost.php?p=30390380&postcount=135Either way I think I'll take a deep breath now, thanks Simon! I'm sure this is just the first of many goofy mistakes I'll be making on projects in the future.

author: Simon
author_rank: Unknown
timestamp: April 12, 2015, 07:00:14 pm
content: The motors won't mind extra voltage for a bit, mosfets are likely rated at more than 5V and the main uC will probably be a 5V version.

author: Zero999
author_rank: Super Contributor
timestamp: April 12, 2015, 07:02:38 pm
content: Quote from: Simon on April 12, 2015, 07:00:14 pmThe only problem I can see is the extra current drawn by the motors at 5V could cause the MOSFETs to overheat but if it's not for very long or operated at full power then it's unlikely any damage will be done.

author: Simon
author_rank: Unknown
timestamp: April 12, 2015, 07:04:38 pm
content: The port will have throttled that fairly quickly so I'd guess not.

author: niblnabl
author_rank: Newbie
timestamp: April 12, 2015, 07:06:01 pm
content: Alright, you guys and this community are amazing. Thanks the both of you, completely cleared my worry now. Gonna go have fun on my day off thanks to you two.

author: mikerj
author_rank: Super Contributor
timestamp: April 12, 2015, 07:42:05 pm
content: Quote from: Hero999 on April 12, 2015, 07:02:38 pmThe reason it glitched is (most likely) because the USB port simply couldn't supply sufficient current to power the motors, so the voltage dropped. Ergo no damage to the MOSFETs or motors.Even a fairly small Lipo battery will be able to supply significantly more current than a computer USB port can.

author: niblnabl
author_rank: Newbie
timestamp: April 12, 2015, 07:47:54 pm
content: Gotcha, my biggest worry was that it was at 5 volts, and in my limited knowledge I was worried about overvolting some component driving the motors that shouldn't get 5v. Now I understand it would be current that would do the damage.Thanks Mike!