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ESP8266 Sleep, how to wakeup without external input?

PostPosted: Sat Mar 24, 2018 4:19 am
by arbj
Hi,

I am trying to make a temperature logger for my solar panels. Every 15 mins the ESP module will connect to the internet hotspot, read the temperature (TC1047 sensor) and then upload to Google sheets using IFTTT web hooks service, then go back to sleep until the next 15 min after which the cycle repeats again.

I plan to use a ESP-12E device for this and a resistance network to bring the 1.75 V (max) output from the TC1047 sensor to 1V level of the ADC.

The plan is to power the entire system with a CR2032 coin cell.

I have developed the code for the above system, its is working well. I can also get it into sleep state, however I do not understand how to wakeup the ESP module every 15 minutes internally using just the software.

I have searched the internet but they all have examples of wakeup using an external pin (WAKE) connected to the reset.

Could anyone inform me how I can wakeup the ESSP device from within the software??

thanks
a

Re: ESP8266 Sleep, how to wakeup without external input?

PostPosted: Sat Mar 24, 2018 4:45 am
by schufti
not possible due to a design flaw ....
(it wakes up but fails to boot user code)

Re: ESP8266 Sleep, how to wakeup without external input?

PostPosted: Sun Mar 25, 2018 3:27 am
by Luc Volders
If you are using a NodeMCU it will work for sure !!
I did this myself.

What you have to do is to connect GPIO16 (D4 on the NodeMCU) to the reset pin.

Just be aware that the maximum sleep time is 71 minutes because of the timer being an unsigned integer value.

Luc

Re: ESP8266 Sleep, how to wakeup without external input?

PostPosted: Sun Mar 25, 2018 3:40 am
by schufti
Luc Volders wrote:What you have to do is to connect GPIO16 (D4 on the NodeMCU) to the reset pin.
Luc

and that is exactly what he allready found and asked for possible different solution
arbj wrote:I have searched the internet but they all have examples of wakeup using an external pin (WAKE) connected to the reset.