TL;DR: check polarity before plugging your DIY circuits into others!!!

*goes off to watch some Lucky Star and drink some booze*
*notices phone battery dying after 3rd pint*

But my charging cable that Huawei delivered with this thing is way too short... Well that ain't no problem, I can make one of my own 😎

But I'm tipsy.. sound I really enter the workbench in this state?

*goes off to build a charging cable anyway*
But what was USB-A male connector's polarity again? Oh, there's the fan's USB connector that I've made in the past. Let's check on that one. So, left is positive and right is negative?

*solders the wires on*
Snip, strip, stick, done! Well that was easy. I guess that all those failed soldering attempts and lost pads in the past as a means of training did pay off in the end!

*plugs phone into Raspberry Pi media center through new charging cable*

Strange sounds coming from the speakers.. well that's odd. Reverse polarity or maybe the Pi can't handle a 1A load from my phone?

*plugs phone into the 5V 5A charging hub that I've made earlier*
That oughta do.. current limits should be no more in that thing.

*charging hub makes high-pitch noise similar to the Pi speakers*
Definitely a reverse polarity, isn't it :') let's check on the Gargler...
Oh shit! It is a reverse polarity mistake!!! Should've checked this earlier >_<

*resolders wires properly*
Alright, finally done.. as I'm writing this post, my phone's charging from the Raspberry Pi through my fixed charging cable now...

Lesson learned. Always check on the internet what the pinout is before soldering anything, don't solder while tipsy, and be fucking grateful that this phone has reverse polarity protection in it.

Nexus 6P with all its shortcomings regarding power delivery and battery management, luckily it's got reverse voltage protection features built-in. Otherwise it might've costed me my phone. Always double-check before plugging anything into something else!!!

  • 5
    I always triple check polarity.
    Thats why incidents like these are very rare for me :P

    PS. How could you not know which one is positivie?? On 100% they are color coded!
  • 7
    @Gregozor2121 I wouldnt know that, same reason that I will never be able to work with resistors unless somebody else labels it for me.
    That is one of the few reasons Im not working with electronics. Im mentally capable of taking the necessary steps but everything is color coded and Im colorblind.
  • 3
    Sorry to heat that you are colorblind...

    I dont use resistors color code, too much hassle. I just use multimeter to check their value.

    I dont trust colors, i always check voltages with multimeter because sometimes i manage to switch colors by accident 😥. (Thats how i fried my sdr dongle... , I used 2 usb female ports and one of them had inverted leads...)
  • 2
    @Gregozor2121 I was working with bare plugs, so only the USB-C side had these little markings on it saying V and G. The USB-A side didn't.. and I still haven't memorized the pinout on that one 😅
  • 4
    Well fucked a power bank in similar situation, made a led something one day and didn't finish, next day I looked at it and plugged it to a Chinese 4 lipo power bank....
    Open the stuff... Used a copper wire as sprint and didn't isolate it, shot circuited everything.
    Well... Got 4 new lipos for my collection. Lesson learned... Not just check but finish a project or scrap it in the same day.
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