ESP8266 Community Forum

- Sun Nov 01, 2015 10:01 pm #32803 Hi Everyone,

I'm trying to make a custom pcb for an esp-12E. I'm not a very technically skilled person (yet) so I was hoping to reverse engineer this board as a starting place for building my custom pcb.
http://s3.electrodragon.com/wp-content/ ... 50x350.jpg

So what I'm asking is, does anyone know what that yellow thing is on the board? My guess is a cap, but I don't know what purpose it serves?

Bonus points if you can name and label everything in the picture.

Double bonus if you draw a circuit diagram (this might be asking too much haha).

Thanks for your help.

- Sun Nov 01, 2015 10:38 pm #32805

So what I'm asking is, does anyone know what that yellow thing is on the board? My guess is a cap, but I don't know what purpose it serves?

Yes, that's a cap (judging by the package a tantalum cap, propably around 10-100uF). It's needed to stabilize the output of the linear regulator (without it, the output voltage will drop out of regulation, when the ESP suddently draws current). The datasheet of the regulator usually specifies the minimum capacitance you need.

Double bonus if you draw a circuit diagram (this might be asking too much haha).

Not much going on there...
On either side of the cap are 2 resistors (used as pull-ups for the buttons), on the bottom there's a regulator and that's it...