ESP8266 Community Forum

- Wed Apr 22, 2015 5:40 pm #15324 For all of you having this reset problem, please post your circuit and a rough idea of your parts placement and maybe we can help.

- Thu Apr 23, 2015 12:19 pm #15397 Bingo, i've cut the RST wire close to the ESP chip and put a 100nf Capacitor from RST to ground. First tests looking good, switched for a few hundred times now with load and no more resets. Before it reset almost every time.

ESP8266_back.jpg

Edit: Modified a second module, also running fine now

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- Thu Apr 23, 2015 1:23 pm #15400 According to the ESP8266 literature, the EXT_RSTB pin is active low, meaning it should normally be held high.

In some circuits, like the Olimex one, they've pulled this pin to 3.3v with a 12k resistor. This is pretty common practice for mcu reset inputs.

So for the ESP-01 I would suggest adding a resistor from the RST pin of your socket to 3.3v, or even just joining RST to 3.3v if you're not going to need a reset button, instead of having to directly mod your ESP-01.

- Thu Apr 23, 2015 1:42 pm #15403 The problem is not the pull-up resistor (is is already pulled up internally) but the design of the ESP-01 module. When you switching relays the RST line is picking up EMP/noise and will cause resets. Just touch the RST pin with a screwdriver and you will see what i mean. Even with a 10K pull-up this will happen. The wire from the RST header pin to the ESP chip acts as an antenna picking up EMP/noise. The ESP chip is very sensitive to this noise. Since my modification, I have not seen any resets. Down side of this mod is to flash the device I have to GND GPIO0 and power cycle the device to get into flash mode. But I can live with that.