ESP8266 Community Forum

I believe 10 pcs of these adapters for US $2.65 is a good price. Headers included.
Several vendors on Aliexpress, like this one.


There is a 10k pullup on CH_PD and a 10k pulldown on GPIO15 (EDIT: initially and wrong: GPIO2).
There is also an R0 (0 ohm resistor / shortcircuit), and an empty pad on the backside for an SMT transistor (I assume).
To me the transistor pad looks like some layout error fixed by the R0. The empty pad could potentially be used for a decoupling chip cap:

ArnieO wrote:There is also an R0 (0 ohm resistor / shortcircuit), and an empty pad on the backside for an SMT transistor (I assume).
To me the transistor pad looks like some layout error fixed by the R0. The empty pad could potentially be used for a decoupling chip cap

No error there... I haven't tested this, but it looks like you can mount a voltage regulator (SOT-89) on the back and remove the 0-Ohm resistor to get an on-board 3.3V supply. However there are no pads for caps (which are mandatory for most LDOs) and no output pin for the regulated 3.3V, so I'm not sure how useful this is.

lethe wrote:

ArnieO wrote:I haven't tested this, but it looks like you can mount a voltage regulator (SOT-89) on the back and remove the 0-Ohm resistor to get an on-board 3.3V supply. However there are no pads for caps (which are mandatory for most LDOs) and no output pin for the regulated 3.3V, so I'm not sure how useful this is.

Wouldn't that be the outputs going to the ESP? You could maybe solder 5V (or higher) to the pads where the R0 is and power it that way.

You sure GPIO2 resistor is pull-down? I think that will interfere with flash and/or normal boot.