ESP8266 Community Forum

- Fri Sep 29, 2017 5:43 pm #70469 You can measure the resistance of a bare module. Vcc to the reset pin. I did this a while ago and because I'm getting old I can't remember exactly what I found.

I think the ESP-12E and ESP-12F had 12.5K on reset. The ESP-07 did not have a pull up. The ESP-12S has pull ups on the reset and GPIO-0 and GPIO-2 along with pull down on GPIO-15.

- Sat Sep 30, 2017 1:35 am #70471 ESP-12F and ESP-07 rings a bell ....

- Sat Dec 16, 2017 8:57 am #72523

CH_EN puts the module in the lowest powered state. RTC memory is not powered. I have been using CH_EN as a reset in my latest project. viewtopic.php?f=11&t=15929

I have RST connected to GPIO16 in case I want to use it for sleep/wake operation. I have some circuitry connected to the three button switches that will provide a high on CH_EN to power up the device. I use a GPIO pin to hold CH_EN high. After a timeout with no activity the GPIO pin goes low and turns the ESP off.

I like the option of using CH_EN as a reset for the ESP8266.

Hi, to start up the ESP8266 in flash mode, is it ok to use CH_PD instead of RESET, while simultaneously pulling GPIO0 low so as to enter flash mode?

Some, like http://hallard.me/esp8266-autoreset/ and nicknamed "igrr" in https://github.com/esp8266/Arduino/issues/22 advocate reset through CH_PD will others like (nickname) tttapa in https://tttapa.github.io/ESP8266/Chap06 ... ading.html use the RESET pin of the ESP8266 to reset the module.

Second part of the question: I would like to use the DTR breakout from the FTDI USB-serial adapter as a means to reset and initiate flash mode of the ESP8266. Do I pursue the CH_PD or the RESET pin resetting method?

It is never too late to learn

- Sat Dec 16, 2017 1:20 pm #72525 Yes. I use CH_PD/EN as the start up for development and also in most battery powered projects where I want a signal like a PIR to start up the module via the CH_PD/EN line.

In development manual or autoflash into program mode works fine using CH_PD/EN and has advantages over using reset. See viewtopic.php?f=13&t=15469