Arduino Forum

Using Arduino => General Electronics => Topic started by: avistein on Sep 03, 2016, 09:38 am

Title: [SOLVED]Connecting esp8266 using a 5V dc source and a 10K pot
Post by: avistein on Sep 03, 2016, 09:38 am
I have this one : http://www.amazon.in/ESP8266-Serial-Wireless-Transceiver-Module/dp/B00O34AGSU?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00 (http://www.amazon.in/ESP8266-Serial-Wireless-Transceiver-Module/dp/B00O34AGSU?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00)
Now it works on 3.3V.I don't have any voltage regulator.So I am thinking to use an old android charger(output:5V) and a 10K pot and regulate it to 3.3V. So will this be a problem to connect the esp8266 this way?
Title: Re: Connecting esp8266 using a 5V dc source and a 10K pot
Post by: OldSteve on Sep 03, 2016, 09:56 am
I have this one : http://www.amazon.in/ESP8266-Serial-Wireless-Transceiver-Module/dp/B00O34AGSU?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00 (http://www.amazon.in/ESP8266-Serial-Wireless-Transceiver-Module/dp/B00O34AGSU?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00)
Now it works on 3.3V.I don't have any voltage regulator.So I am thinking to use an old android charger(output:5V) and a 10K pot and regulate it to 3.3V. So will this be a problem to connect the esp8266 this way?
Yes, it will be a problem. You can't do that. 500uA will flow through the pot, and you can only use a fraction of that. An ESP8266 uses far more current.
Forget the idea of using a voltage divider. Use a DC-DC converter, or at the very least, a linear regulator.
Doesn't your Arduino board have a 3.3V regulator? Or doesn't it supply enough current? (I've never used an ESP8266, and can't be bothered looking up it's specs.)
Title: Re: Connecting esp8266 using a 5V dc source and a 10K pot
Post by: avistein on Sep 03, 2016, 10:36 am
Yeah you're right.I just now checked with a micro servo with regulated voltage 5V and the servo could not run properly ,while without the pot it ran smoothlu.So it's not getting enough current.Btw the charger is rated at 1A output.
No the 3.3V can give a max output of 50mA and the esp8266 requires more current(max=200mA) than that.It seems that I gotta buy a regulator.What's your opinion about LM1117 or will it get too much heated without heatsink?
Title: Re: Connecting esp8266 using a 5V dc source and a 10K pot
Post by: OldSteve on Sep 03, 2016, 11:52 am
It seems that I gotta buy a regulator.What's your opinion about LM1117 or will it get too much heated without heatsink?
An LM1117 should be fine for a 5V to 3.3V conversion at that current. It would dissipate about 340mW at 200mA.
Title: Re: Connecting esp8266 using a 5V dc source and a 10K pot
Post by: Wawa on Sep 04, 2016, 09:45 am
No the 3.3V can give a max output of 50mA...
Depends on which of Arduino.
The Mega and Uno_R3 are 150mA (50mA is wrong in the datasheet).
A Nano is 50mA, and a Nano clone is <20mA.
Still better to use an external 3.3volt 1117.
Leo..
Title: Re: Connecting esp8266 using a 5V dc source and a 10K pot
Post by: OldSteve on Sep 04, 2016, 12:44 pm
Depends on which of Arduino.
The Mega and Uno_R3 are 150mA (50mA is wrong in the datasheet).
A Nano is 50mA, and a Nano clone is <20mA.
Still better to use an external 3.3volt 1117.
Leo..
When he said 50mA, I automatically assumed a Nano.