ESP8266 Community Forum

- Tue May 26, 2015 12:49 pm #18526 Hey guys, I couldn't find a good writeup for this (only bits and pieces everywhere) so what is the ideal way to use the esp 1 and 12 modules on custom pcbs?

As far as I know:
01:

RX - serial-read pin, if not connected tie to ground? Can be used as an IO pin (https://github.com/eadf/esp8266_stdout)
GPIO0 - (10k) pullup for startup, pull high at reset for programming mode, otherwise use as GPIO
GPIO2 - (10k) pullup for startup, pull high at reset for programming mode, otherwise use as GPIO
GND - Gnd
VCC - 3.3V!, 100nF decoupling ceramic cap near the pin to Gnd
RST - (10k) pullup + switch to gnd for a restart (is there also a cap to gnd needed?)
CH_PD - (10k) pullup
TX - serial-write pin, if not connected tie to ground?

Another (e.g. 22uF) cap at the power converter/IC/source

Did I miss something here? Is 10k the right value, or is there any reason to use another for the pullups? Here http://www.esp8266.com/viewtopic.php?f=13&t=3119 we discussed if gpio 0 and 2 can somehow be pulled low while still starting the esp... no real result yet. Does anyone know?

12:

- VCC, Gnd, CH_PD, GPIO2, GPIO0, RX, TX stays the same
- GPIO15 (10k) pulldown at startup, afterwards normal GPIO?
- GPIO16 and RST directly connected to be able to use sleep mode?
- nRST (10k) pulldown
- ADC pins?
- GPIO4,5,12,13,14,16 are just gpios (if not used tie to Gnd?)

I would be thankful for every error here that you guys correct And for every good source that you have on this!
Thanks

- Tue May 26, 2015 2:01 pm #18528 nRST should be pulled-up to 3.3V, otherwise it will never start ...

- Tue May 26, 2015 3:15 pm #18531 Isn't nrst reverted reset on the 12? Normally reset has to be tied to vcc.. so reverse = pulldown, right?

- Tue May 26, 2015 9:20 pm #18552 the "n" means it is Active Low, which means that the reset will occurs when it is tied to ground and that normal state should be high.
This RST signal is the same on all ESP modules.