I have a basic circuit, with just an LED and a switch between the ground and the RST pin.

When I press the button, the LED glows lightly but RST is not triggered.

Of course if I remove the LED, the ESP will reboot after the switch push.

What I am missing here?

My schematics, but I don't know how to represent the RST pin that is always at 3.3V and should be triggered down to the ground:


simulate this circuit – Schematic created using CircuitLab

Overall context: I want to be able to discern a reset triggered out of the deep sleep mode (i.e. pin16 acting as a switch) from a reset triggered manually (with my user switch). To achieve that, my solution is to connect the switch to a gpio and the rst, then to "isolate" the rst from the gpio with a diode (so that rst pin will not change gpio state when triggered from elsewhere).enter image description here

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    \$\begingroup\$ Don't wire LEDs with microcontroller without adding some resistor in series with LED. \$\endgroup\$ – TicTacToe Oct 7 '15 at 10:24
  • \$\begingroup\$ LEDs have a voltage drop upwards of 1.7V. This device that you are using probably has internal pul-up resistor on RST. Thus when you push the switch there is still >1.7V at the RST pin which is likely not low enough to reset the deivce. \$\endgroup\$ – Golaž Oct 7 '15 at 10:25
  • \$\begingroup\$ Also for the record, please use proper schematics next time...As its really difficult to read these sort of diagrams. \$\endgroup\$ – Golaž Oct 7 '15 at 10:26
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    \$\begingroup\$ -1 for the annoying wiring diagram instead of a schematic. \$\endgroup\$ – Olin Lathrop Oct 7 '15 at 11:09
  • \$\begingroup\$ I will try with a diode intead of a LED, after measuring it, this should be the solution \$\endgroup\$ – bixente57 Oct 7 '15 at 12:05

Looking at you layout, it looks like you have the LED in series with the switch. If you are trying to get a reset on low and the LED to light at the same time, then connect the LED anode to v+ via a resistor and the cathode to RST. Then connect RST to one side of the switch and 0v to the other side of the switch.


simulate this circuit – Schematic created using CircuitLab

  • \$\begingroup\$ That is not working any better, but I think this is because of the LED, I will try with a diode \$\endgroup\$ – bixente57 Oct 7 '15 at 12:04
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    \$\begingroup\$ Data on your device says - "RST - this is the reset pin for the ESP8266, pulled high by default. When pulled down to ground momentarily it will reset the ESP8266 system. This pin is 5V compliant." There is no way this would not work in this case. You must have wired it up incorrectly. Thanks for the schematic Icy. \$\endgroup\$ – HandyHowie Oct 7 '15 at 13:06

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