AsyncLabs Forums

[Flipo]

I probably did something really stupid. I tried powering the YelloJacket using a 12v source on the RAW and GND pins. At first the leds seemed to light up but the board would reset shortly after the wifi led would light up. Then for some reason, not sure if I made a false contact or something, but something burned and I saw a lot of smoke. The strange thing is that the YellowJacket still seems to work fine when I power it over USB.

So I'm a bit worried, should I continue using it ? I assume if I saw smoke then something must be seriously damaged, but it still works...

Also, is it safe to power it from a 12v source (on the RAW and GND pins) or is this why it blew ?

Thanks !

[John_Ryan]

The RAW pin should be able to handle 12v fine if it's the same deal as the Arduino Pro Mini.

I accidentally connected 24 volts to an Arduino BT once and got sparks, bang, and blue smoke, but the reason was obvious. Your symptoms sound the same except for the sparks and bang.

I've had my yellowjacket for months but I haven't fired it up yet because the max input voltage and which pin to use is a a bit unclear, and now I know to steer away from 12 volts but I'm sorry if thats new information thats arrived at your expense.

Here's a copy of that part of the schematic, mic5219 is rated up to 20v and SOT-23-5 only 9 volts - so I too would like to know the maximum input of the RAW pin.

1-raw.jpg (37.04 KiB) Viewed 168 times

[Flipo]

So if I understand correctly I probably blew the voltage regulator, meaning I can still use the board using vcc at 5v but I can't use the raw port anymore ?

[Flipo]

I just did another test, with a voltmeter I checked the 5v and 3.3v pins, they both output 3.3v, is this normal ? I assume not... In this case, should I still be using the YellowJacket, is it safe ?

Edit : I tested some digital pins and they output 5v so I assume all is fine...

[GregEigsti]

Ouch! Sorry to here that. Sounds like you have fried the +5v "section" of your YJ. You said it works with USB power - does it work in the later scenario where you are getting +3.3v out of the +5v pin?

I have noticed... there are many new cheap electronic devices that utilize a USB connection for charging/etc. - the upside to this is that they tend to ship with a wall wart that has a standard USB connector which outputs a regulated +5v (they are becoming ubiquitous). Potentially you could use one of these "USB power wall warts" and USB cable to power your YJ? But then this would mean leaving the FTDI programmer board permanently attached. But if you found a way to make it work without the programmer board then that is probably a better solution (+3.3v out of the +5v pin scenario). I wonder if the USB power skips the YJ's +5v regulator because it is already regulated? This would (potentially) shed some light on why it works for you with USB power.

As far as danger goes... What is the intended installation/purpose of this YJ? If it is to install in a remote/sensitive place then I would think (maybe) about replacing it. If it is meant for a "home project" (where you can monitor it) or a project which will only be powered on when you are present (e.g. RC car) then I would not worry too much. I would think that it is safe to continue development on (where you are right there uploading code and testing it). You are probably OK but this is from a non EE and just a guess - kind of up to you and your comfort level.

I will probably be launching into playing with my "stockpiled" YJ soon. Have always been interested in EEGs (brain wave measurement) and got intrigued by some of the new toys that use a simple headband to monitor brain activity and utilize that for game control (Force Trainer and Mindflex). I ordered a Mindflex based upon its ability to provide more datapoints than the Force Trainer and figure that the YJ is a perfect addition to the headband to capture and make the data available on the net. (Listening to the kids beg for one while I was researching did not hurt either!) I figure the YJ's small form factor lends it well to installing into the headset and using the output (serial data transmitted via the YJ) to program the VCR would be fun.

Mindflex
http://www.mindflexgames.com/
Force Trainer
http://www.toysrus.com/product/index.jsp?productId=3531167
Inspiring Mindflex hack
http://ericmika.com/itp/brain-hack

Greg

[Flipo]

After some further testing the board seems to work normally, I assume only the power regulator blew meaning all should work except the RAW pin. I guess I can power it using the vcc pin on the FTDI header using a 5v source...