No wakeup after complete discharge of the batteries

Moderators: grovkillen, Stuntteam, TD-er

Post Reply
Message
Author
User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

No wakeup after complete discharge of the batteries

#1 Post by spicer » 03 Sep 2019, 18:58

German:
Hallo Gemeinde
Warum bootet der ESP8266 nicht, nachdem die Akkus komplett entladen waren und die Solarpanels wieder Strom liefern?
Ich denke, das dies wegen dem langsamen Spannungsanstieg ist.
Gibt es einen Trick (wie ein R-C Glied), um das hinzukriegen?


Translator:
Hello community
Why does the ESP8266 not boot after the batteries have been completely discharged and the solar panels are supplying power again?
I think that's because of the slow increase in voltage.
Is there a trick (like an R-C link) to do that?

User avatar
grovkillen
Core team member
Posts: 3221
Joined: 19 Jan 2017, 12:56
Location: Hudiksvall, Sweden
Contact:

Re: No wakeup after complete discharge of the batteries

#2 Post by grovkillen » 03 Sep 2019, 19:10

Perhaps using a voltage regulator in-between?
ESP Easy Flasher [flash tool and wifi setup at flash time]
ESP Easy Webdumper [easy screendumping of your units]
ESP Easy Netscan [find units]
Official shop: https://firstbyte.shop/
Sponsor ESP Easy, we need you :idea: :idea: :idea:

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#3 Post by spicer » 03 Sep 2019, 19:14

Yes. I use a step down converter (7-12V to 3.3V).

User avatar
grovkillen
Core team member
Posts: 3221
Joined: 19 Jan 2017, 12:56
Location: Hudiksvall, Sweden
Contact:

Re: No wakeup after complete discharge of the batteries

#4 Post by grovkillen » 03 Sep 2019, 19:34

Aren't you powering it with 5V?
ESP Easy Flasher [flash tool and wifi setup at flash time]
ESP Easy Webdumper [easy screendumping of your units]
ESP Easy Netscan [find units]
Official shop: https://firstbyte.shop/
Sponsor ESP Easy, we need you :idea: :idea: :idea:

User avatar
ThomasB
Normal user
Posts: 400
Joined: 17 Jun 2018, 20:41
Location: USA

Re: No wakeup after complete discharge of the batteries

#5 Post by ThomasB » 03 Sep 2019, 19:35

One way to solve this is to use a brown out detector. This provides a reset after the voltage becomes valid. Same concept as the Power Good ("PWR_OK") signal on a ATX PC power supply.
For example: http://www.hnilica.cz/radek/zim/Electro ... cuits.html

- Thomas

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#6 Post by spicer » 03 Sep 2019, 19:36

No. 3.3V.
5V is very bad for the ESP :D

User avatar
grovkillen
Core team member
Posts: 3221
Joined: 19 Jan 2017, 12:56
Location: Hudiksvall, Sweden
Contact:

Re: No wakeup after complete discharge of the batteries

#7 Post by grovkillen » 03 Sep 2019, 19:37

So what board are you using since you don't have a 5V VIN?
ESP Easy Flasher [flash tool and wifi setup at flash time]
ESP Easy Webdumper [easy screendumping of your units]
ESP Easy Netscan [find units]
Official shop: https://firstbyte.shop/
Sponsor ESP Easy, we need you :idea: :idea: :idea:

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#8 Post by spicer » 03 Sep 2019, 19:44

ATM i use a nodeMCU and give power over 3V pin. Vin is not connected. I know, is not a clean solution :)
Later i will use a "naked" ESP-12F modul.

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#9 Post by spicer » 03 Sep 2019, 19:47

ThomasB wrote:
03 Sep 2019, 19:35
One way to solve this is to use a brown out detector. This provides a reset after the voltage becomes valid. Same concept as the Power Good ("PWR_OK") signal on a ATX PC power supply.
For example: http://www.hnilica.cz/radek/zim/Electro ... cuits.html

- Thomas
Yes. This is a possible solution. With the TCM809 easy :)

TD-er
Core team member
Posts: 1487
Joined: 01 Sep 2017, 22:13
Location: the Netherlands
Contact:

Re: No wakeup after complete discharge of the batteries

#10 Post by TD-er » 03 Sep 2019, 21:15

Maybe the ESP is trying to boot and thus discharging the battery more than the panels can charge it.
The EN pin on the ESP must be pulled high to boot the ESP.
Maybe you can make a simple trigger to only pull it high above some level to give the panels opportunity to get the batteries charged again.
It could also help to prevent discharge below some level.

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#11 Post by spicer » 03 Sep 2019, 21:30

Good idea.
I still have unused OpAmps.
This allows me to build a Schmitt trigger for the EN.

User avatar
ThomasB
Normal user
Posts: 400
Joined: 17 Jun 2018, 20:41
Location: USA

Re: No wakeup after complete discharge of the batteries

#12 Post by ThomasB » 03 Sep 2019, 23:00

I still have unused OpAmps.This allows me to build a Schmitt trigger for the EN.
Don't forget that this application will require a micropower OpAmp; Single supply, rail-to-rail, and capable of operating at very low voltage.

- Thomas

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#13 Post by spicer » 03 Sep 2019, 23:06

Is a LMC6482.
But i think, i solve this with ThomasB's "brown out detector".

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#14 Post by spicer » 05 Sep 2019, 19:44

I build a circuit.
If the voltage (Ubat) is to low (adjustable with R4) the EN is L.
V1 (3.3V) is after the step down converter.
It works ^^ Thx TD-er
Attachments
Auswahl_001.png
Auswahl_001.png (64.62 KiB) Viewed 734 times

TD-er
Core team member
Posts: 1487
Joined: 01 Sep 2017, 22:13
Location: the Netherlands
Contact:

Re: No wakeup after complete discharge of the batteries

#15 Post by TD-er » 05 Sep 2019, 19:52

Maybe you also want to add some hysteresis, or else it would not be able to charge the batteries again and keeps rebooting if the current needed for booting is pulling the voltage just below your set threshold.

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#16 Post by spicer » 05 Sep 2019, 20:01

That's what I thought about first.
But if the power is insufficient when booting, the EN is immediately set to L again.
A "flickering" would of course be possible and not desirable.

When I apply a resistor from out to +, I have a hysteresis (non-inverting Schmitt-trigger).
Attachments
Auswahl_001.png
Auswahl_001.png (73.31 KiB) Viewed 720 times

TD-er
Core team member
Posts: 1487
Joined: 01 Sep 2017, 22:13
Location: the Netherlands
Contact:

Re: No wakeup after complete discharge of the batteries

#17 Post by TD-er » 05 Sep 2019, 23:34

Maybe also place some small capacitor parallel to R4 and one over V1.

I can imagine the DC/DC converter and the charging circuit may not give the most clean signal.
So by adding a small capacitor over them, you will eliminate most of the spikes introduced by those converters.
In order to simulate, you may need to add a 50 kHz (or more?) signal on top of your sine wave with an amplitude of 50 mV (?)

Wiki
Normal user
Posts: 138
Joined: 23 Apr 2018, 17:55

Re: No wakeup after complete discharge of the batteries

#18 Post by Wiki » 06 Sep 2019, 13:50

It would be helpful to get an idea about your power supply scheme. Do you use a protection board for liion batteries?

If yes, have a look at its datasheet. Most protection boards are starting the charging cycle after shutdown of the power supply caused by low voltage of the battery with very low current. So switching the ESP on too early means that you won't get the battery alive again. You will have to charge the battery at least up to 3.2-3.3V before switching the ESP on to get the circuit alive.

This is the reason why power banks in most cases don't deliver power while being charged.

User avatar
spicer
Normal user
Posts: 34
Joined: 01 Jul 2019, 16:40

Re: No wakeup after complete discharge of the batteries

#19 Post by spicer » 06 Sep 2019, 15:40

I use two (serial) Panasonic 18650 NCR18650B Li-ion battery 3.7V with protection PCB 3400mAh.
Simple way :D

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 1 guest