How to power up ESP32-DevKitC without USB port?

DROBNJAK
Posts: 2
Joined: Tue Oct 24, 2017 6:31 pm

How to power up ESP32-DevKitC without USB port?

Postby DROBNJAK » Tue Oct 24, 2017 6:35 pm

I need ESP32-DevKitC to run away from power provided by USB port, like directly from battery that doesn't have USB cable.

What pins do I need to power up, 3.3V or 5V and what are min & max limits?

ESP_Sprite
Posts: 9708
Joined: Thu Nov 26, 2015 4:08 am

Re: How to power up ESP32-DevKitC without USB port?

Postby ESP_Sprite » Wed Oct 25, 2017 2:16 am

You only need to supply 5V. Make sure the power source (batteries) can handle a 500mA spike without the voltage dropping too much. Limits are set by the (iirc) AMS1117-3.3 LDO, which the datasheet indicates to be 4.6V to 17V. I think you should be able to go lower than that (probably still works at 3.5'ish volt) but there's no guarantee there.

DROBNJAK
Posts: 2
Joined: Tue Oct 24, 2017 6:31 pm

Re: How to power up ESP32-DevKitC without USB port?

Postby DROBNJAK » Wed Oct 25, 2017 3:14 pm

I don't have 5V. I have 3.7V from LiPo with 3.3V regulator.

Can I connect 3.3V from power supply to the 3.3V pin in a top left corner of the ESP32-DevKitC? I mean, its from battery, so it doesn't have Micro USB cable.

Its not clear what that 3.3 pin is doing, is it IN or OUT pin?

I was completely unable to find a datasheet for ESP32-DevKitC. Can you please give me URL where this info was held?

ESP_Sprite
Posts: 9708
Joined: Thu Nov 26, 2015 4:08 am

Re: How to power up ESP32-DevKitC without USB port?

Postby ESP_Sprite » Thu Oct 26, 2017 1:10 am

The getting started guide links to the schematic. Looks like there's nothing there that would break if you feed the thing 3.3V using an external (ultra-low-drop) regulator.

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