Damaged IO pin on Spark Core; any chance of salvaging it?

I was doing some rewiring and didn’t realize my Core and the attached devices were powered up. Somehow, I managed to short the D1 pin to 12V and it remained that way for a few minutes before I found my Spark Core hot and completely nonfunctional.

I discovered by using a multimeter that GND, 3v3 and D1 are shorted together. I tried removing the 3v3 regulator first (because it was easy), but that was not the culprit.

I’m going to try disconnecting the D1 micro pin from the board to see if that makes a difference.

Originally, I was posting asking for advice as I hadn’t figured out which pin to cut. I dug into the STM32F103CB data sheet and figured out that D1 = PB6 = Pin 58. I’m firing up my microscope and trying to precisely cut the right pin. I decided to leave this post up since it might benefit someone else with the same issue.

I suspect that you’ll have to repurpose your Core as a high-tech paperweight (for small books only). Keep in mind that in almost all logic chips have blocking diodes that shunt excess voltage to the power rails, and I’m not aware of any zener circuitry in a LDO regulator to prevent the rail from flying high.

In my experience with Microchip PIC16s, shorting the pins to out-of-range voltages just blows them out–the processor keeps right on working, but you’ll never get any functionality out of that pin. In that D1 is shorted to the power rail(s), I’d say that the CPU is toast. Not to mention the CC3000…

If you manage to raise Lazarus from the dead, let us know :wink:

I’m starting to think you’re right. Cutting the connection between the pin and the processor wouldn’t do anything - it must be shorted internally. Not to mention that it’s impossibly tiny! And yes, it’s not even heavy enough to be a great paperweight!

I’m tempted to try replacing the micro, but then if the CC3000 is fried also then I’m really putting a lot of effort in for a questionable return. Probably should just order another Photon :slight_smile: .

I had a really good streak of not destroying my electronics; I guess it was bound to end sooner or later.

Sure, beat me to a Photon… :stuck_out_tongue_winking_eye:
Even if you replaced the micro, keep in mind that you’ll need a JTAG programmer to get the Particle firmware back in there, before it will even appear as a USB device on your computer.

We’ve all had smoke at some point or another. My personal favorite was plugging in an LM324 op-amp upside-down. It didn’t work quite right…and while I got the oscilloscope out, there was a “crack” from the breadboard. I’ve also experienced a 100µF 400v electrolytic capacitor explode…it was only getting 30v, forward biased. I didn’t consider the 120Hz ripple current at 8A, though. Consider yourself seasoned.

I spoke too soon… I think the post office lost my photon.

@zach, @christine: Next step for Particle: ship an Electron and GPS module with every order, giving each customer realtime live tracking for every shipment :stuck_out_tongue_winking_eye:. I’m not sure about the ROI, though…


I spoke just too soon- they just made a special evening delivery!

@WebDust21, I think that’s an awesome idea. Pair a custom GPS/Power shield up with Electron V2 and a bunch of batteries and you can watch your package fly across the country to your doorstep! I think I would pay for that, especially since you would be able to repurpose everything.

2017 probably would be a good release date though; I think the Particle team probably deserves some actual time off!

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@dome That was a 100% tongue-in-cheek joke. Only the millionaires would want to pay $150 for the Electron and a GPS module…

I suppose it’s not a great idea to post on the forums with a low-grade fever - all of my sense of subtlety goes out the window.

However, that setup sure would have come in useful earlier this week.