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Topic: Not a arduino, But a ESP8266 on batteries>? (Read 1 time) previous topic - next topic

josephchrzempiec

Hello i know the ESp8266 is not a arduino board. But it uses and functions a lot like a arduino with wifi. However my question is i have a whole bunch of PKCELL LP 3.7V 1200mah lipo batteries. I know the ESP8266 takes 3.3v So how can i step down safely with what i have now? I do not have many things to step down voltages. I do have couple of AMS1117 3.3v voltage regulators. and a few resistors here and there. I know i can dosome kind of voltage divider But not on a massive scale for a ESP. I can use a arduino that has 3.3v for it. But then again I'm stuck with using a USB board or power cord and this is a Battery project. I could use some help. Please someone help me? I'm trying to use what i have without spending more money. I'm limited on dollars. Thank you


Joseph

JMeller

Caution - engineers eyes may bleed.

The ESP8266 (ESP-01; mfg - Addicore) works fine with 5v for prototype code for months/years.

josephchrzempiec

#2
Apr 16, 2018, 05:04 am Last Edit: Apr 16, 2018, 05:04 am by josephchrzempiec
This is the esp8266 I have Here. I been reading that the voltqg3 on theses can't go past 3.4 volts the most. Let alone 5v.

JMeller

Judging by the PCB layout, it appears to be carbon copy of mine; its a prototype - learn the tolerances.

DrAzzy

#4
Apr 16, 2018, 06:50 am Last Edit: Apr 16, 2018, 06:52 am by DrAzzy
Apparently people have found that the ESP8266 is surprisingly reliable when overvolted... while I'd hesitate to do so, you might well be able to run it straight off the battery. People also use it with 5v serial and a 3.3v supply without level shifting and other appalling things like that, and generally find it works.

A more spec-consistent way of doing it would be with a very low dropout regulator; I use the AP2114 for running 3.3v devices off a LiPo.
ATtiny core for 841+1634+828 and x313/x4/x5/x61/x7/x8 series Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts (some assembled), mosfets and awesome prototyping board in my store http://tindie.com/stores/DrAzzy

josephchrzempiec

Hello thank you all for the information. I did find some LDO  that DrAzzy said and have order a couple. I thought this will be easy and i can use But it looks like i need more. So i have order a few and they are on the way. Thank you all for the Help.

6v6gt

A series schottky diode can trim about 0.3 volts off.  A 1n400x can trim about 0.7 volts.

josephchrzempiec

Hello 6v6gt thank you for that. I hav2 a foupme of 1n4007 would they do?

6v6gt

One 1N4007 would bring the voltage down from 3.7 volts to 3 volts so you'd be within the specifications for the ESP module. The solution is not ideal because the voltage drop is constant irrespective of the state of the charge in the battery, meaning you have less usable battery life.
This video could be interesting for you. I concerns battery driven ESP8266s and low power considerations: https://www.youtube.com/watch?v=IYuYTfO6iOs&feature=youtu.be

MarkDerbyshire

A LiPo cell will be at 4.2V when fully charged

josephchrzempiec


ElCaron

Hell which 1n400x should I be using?
None, dropping voltage with a diode in a battery application is crazy. It limits your battery life a lot. You want an LDO regulator with
a) low dropout, because that reduces the battery voltage when the charge goes done. It is easy to find one that has less dropout than a diode.
b) low quiescent current, that would drain the battery while the ESP is sleeping.
c) provide enough current for the ESP

a) and b) rule out the AMS1117.

450mA from DrAzzy is still a lot and will cost you some battery life. I myself ran ESPs successfully with HT7333s. They only provide 250mA, which the ESP can reach when transmitting, but that was always fine for me. Maybe add a 3-digit uF cap.

The Wemos D1 Mini has a ME6211, which has 100mV Do. 40uA quiescent current may not be such an issue, depending on how often you want to wake your ESP. What battery life are you expecting?

josephchrzempiec


ElCaron

What type of Ldo would be good?
The type that makes you read other people's postings.

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