I recently acquired some 'ESP8266 SMD Adapter Boards' from Electrodragon. Up till now, they've been working fine. Except... I think I just broke one by attaching it to a 12v power supply. The power supply says it's a 12v 2A DC supply, which would seem to play nice with this (from that linked product page):
On board LDO for 3V3 power, 0.5-1A output (NOT for serial port and other IO pins), input voltage range 5-12V
I have a water sensor and a buzzer soldered to the ESP board, and the requisite GPIO16-RST connection so that sleeping the chip works. I also got some simple DC connectors to take a standard 5.1mm plug and use it as a power supply. Here's a picture of the overall setup.
This has been working perfectly when powered through my FTDI cable, but it's tedious holding the power/ground pins manually (this build doesn't have headers on it, the plan was for this to be a stepping stone to 'mass production' (which is seven units, but still).
I tested the 12v power supply, my multimeter said it was outputting 12.18v. I plugged it into the system, and... poof, magic smoke and a red-hot pin. It came from the little black chip at the bottom of the board:
The middle pin on the near side of the chip is where the smoke was apparently coming from. I unplugged the connection, but the board wouldn't power on again.
The chip that was smoking is imprinted, in barely legible type, "352". It might be "L352". Assuming this is a voltage regulator, is it rated for 12v? Was I sold a falsely-marketed product? I can't find a spec sheet for it, and before I ruin another one I'd like to know if these are 12v tolerant.
Or, is there something wrong with my circuit/soldering? I'm brand new at this, so it's messy, but here are some additional pictures: bottom of the ESP, side view showing some connections better, water sensor module. Don't hesitate to ask if there's any additional information I can provide!
Edit: I've just hooked a fresh board up to 12v power, and watched it a little closer. I seemed to confirm that the voltage regulator couldn't dissipate heat:
It desoldered itself. Impressive.
I'm going to get some 5v power supplies.