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ESP8266-12 deep sleep mode freezes chip

Posted: 21 Nov 2016, 21:25
by Elektrofreak
Dear all,

I am trying to get the ESP8266-12 running on my own board. I am using the current beta firmware (R143 I guess) and I don't have any problems when I don't use the sleep mode.

Concerning the Hardware, I have a 12k pull-up connected to the RESET-Pin. If i additionally connect the GPIO16-pin to the RESET-pin, the chip is stuck in reset (looks like because the current consumption is increased and it does not connect to the WiFi). It does not change if sleep mode is enabled or disabled in the web-interface....

Is this a known problem? How do I fix it?


Many thanks in advance for any hint to get rid of this problem ;)

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 06 Dec 2016, 12:04
by Elektrofreak
Hello everybody,

unfortunately I could not find the issue until now. Could somebody give me some hints to find the root cause? The informations concerning deep sleep mode are very scattered and far from complete on the world wide web...


Many thanks in advance!

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 07 Dec 2016, 12:41
by Drum
Okay, the pullup keeps the reset from doing an automating reset and GPIO 16 pulls it to ground to reset it and wake it up again.

I suspect you may have some other issues. Do you have a schematic, picture... What is your power circuit? Check the wiki there is a section on power, but without much more information it is impossible to suggest anything with any chance of working.

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 03 Jan 2017, 07:40
by Elektrofreak
Dear all,

I finally found the root cause... It is very easy if you know :lol: .

In case you do a proper reset, the ESP8266 needs some time to clear the internal registers. If you connect GPIO16 directly to the reset pin, it will try to do the reset but the reset itself will release the reset. If the reset periode is too short, it could not reset completely all registers and so it might try again to reset or do anythink else than what you like it to do.

I have captured the reset pin voltage and found the waveform shown in the attachment. As you can see, it tries to reset many times but never really long or clear. After adding a 470R inbetween GPIO16 and the reset pin, it was fine :D . It now discharges the RESET capacity so it will keep the reset state even if GPIO has gone low again for a short periode which is okay for the ESP.

By the way: I removed the 100nF parallel to the reset pin trying to fix it (attached snapshot) but it made it more difficult to find the root cause. Now I have the 12k and the 100n as typically being used plus the 470R for the GPIO16 pin.

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 16 Jan 2017, 20:10
by filo
Hi. Can you show your scheme? I fight all the time with deep sleep in ESP12E with ESPEasy newest FW and I don't know how I doing wrong, but my ESP never wake up! :?

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 17 Jan 2017, 07:55
by Elektrofreak
I don't have a schematic right now. But you can test the following:
  • Check the voltage level / pull up & pull down resistors of GPIO0 (high), GPIO2 (high) and GPIO15 (low)
  • Check that you have a 12k between Reset and VDD
  • Check that you have a 100nF between Reset and GND
  • Check that you have a 470R between GPIO16 and Reset
  • Check that you have a >220µF capacitor and a ceramic 100nF between VDD and GND (as close as possible!)
  • Check that your power supply is capable of zero load (regulation speed at restart!), large current spikes (best >=500mA) and (in case of a buck-dc-dc) that it has a large primary side capacitor
  • Use an oscilloscope and probe the VDD, Reset and GPIO16 voltages
I hope this list is a good help :-)

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 20 Jan 2017, 17:01
by filo
Only last point is not feasible for me because I haven't oscilloscope, but besides fulfill all the requirements. Did not work :(
After ESP sleep down, then send "ets Jan 8 2013, rst cause:5, boot mode:(3,6)" and that's all :(

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 20 Jan 2017, 19:59
by filo
WORKIG ! :D
But ony 120 build, not for 147 ;)

Re: ESP8266-12 deep sleep mode freezes chip

Posted: 06 Mar 2018, 12:39
by Ayoub
Hi guys, I have the same prob here. My ESP-12E won't wake up and the serial monitor shows some randome characters. I didn't understand filo's final response.
Please help me out.