Hello all! Thank you very much for taking the time to check out my post. This may end up being a bit of a noob problem, but after hours of internet searches, I am stumped and am resorting to asking for the collective mind of this forum to help me out.
Basically, I connected a Promini and an audio amp to a battery in parallel. When I turned on the amp, I saw a black cloud of smoke rising from the Promini! I was under the impression that when connected in parallel, current (for the most part) shouldn't be an issue. So I'm stumped as to why it blew it out in the first place. I'll go into some more detail and provide a schematic. Also, please be aware that the speaker and motor were not connected at the time, but I'll include them in my explanation for the sake of thoroughness.
I'm new to drawing schematics, so I hope that this one is drawn properly. Please let me know if I made any major mistakes in the drawing process! Also, I just added a picture of the amp since one wasn't available in the fritzing schematics.
I have a 12V power supply connected to a 5v Arduino Promini (via the RAW pin which accepts up to 12v), a 20W audio amplifier, and a motor (via a TIP120 transistor). This circuit is supposed to play a sound and run the motor after I push a button. Nothing too complicated. At the time of the burnout, I disconnected the motor and speaker, hoping not to pull too much current until I verified everything was in working order. I turned on the Amp just to make sure it was receiving power and I instantly heard a sizzle and saw smoke.
So, my first thought was that I burned out the Arduino by pushing too much current through it. But it was my understanding that as long as the arduino was in parallel to the amp, there shouldn't be a problem. Was I mistaken about this parallel relationship between parts? Or perhaps the high draw of the amp created a "current spike" that the arduino was unable to handle. Or did I just not hook it up right in the first place?
Thanks again for taking the time to read through my problem! I hope that I can learn from this experience!