what is the ESP8266 Wemos D1 mini Max voltage in

I had planned to step down 12V supply to 5V and then feed in to the 5V pin and i ahve teh regulator to do this ready and waiting.

however reading this

it says as below "The recommended range is 7 to 12 volts" I am just wondering if any one has actually tried this an not fried their device, i still planning the external regulator unless anyone has evidence that the pin clearly labeled 5v does indeed support 12v without frying its self.

Cheers

"Device Summary
Microcontroller: Tensilica 32-bit RISC CPU Xtensa LX106

Operating Voltage: 3.3V

Input Voltage: 7-12V

Digital I/O Pins (DIO): 11

Analog Input Pins (ADC): 1

UARTs: 1

SPIs: 1

I2Cs: 1

Flash Memory: 4 MB

SRAM: 64 KB

Clock Speed: 80 Mhz

Wi-Fi: IEEE 802.11 b/g/n:

Integrated TR switch, balun, LNA, power amplifier and matching network
WEP or WPA/WPA2 authentication, or open networks
Power
Power to the Wemos D1 Mini is supplied via the on-board USB Micro B connector or directly via the “VIN” pin. The power source is selected automatically.

The device can operate on an external supply of 6 to 20 volts. If using more than 12V, the voltage regulator may overheat and damage the device. The recommended range is 7 to 12 volts."

They work perfectly well with 5V on the 5V pin.

PerryBebbington:
They work perfectly well with 5V on the 5V pin.

Hi,

I know they do been using them in many projects with 5v supply. I just want to know if they do support 12v as the motors and other components are 12v if i don't need to fit a 12v - 5v regulator that would mean one less component.

I just don't want to brick one of mine testing this claim :slight_smile:

Perhaps I misread your question. I have not tried anything other than 5V on the 5V pin of a D1 mini. No pin on the ones I have is labelled with anything to suggest an input voltage other than 3V3 or 5V. There is no 'Vin' pin on the ones I have, and I don't see a Vin pin on the web page you linked to.

The numbers given sound more like for the Arduino Uno or Nano.

The WeMOS is a 3.3V device, and can be powered either through USB, 5V on the 5V pin or 3.3V on the 3.3V pin.

OK, here is the circuit for the D1 Mini,

Expand!

There is a diode feeding the "5V" line from the USB jack. The "5V" line is apparently used only to feed the regulator and the USB interface chip is powered at 3.3 V from the regulator so it is protected.

It appears that no part connected to the "5V" line is unduly sensitive to voltage so a higher voltage might be usable. However powering at 12 V is extremely likely to overheat and shut down the regulator.


OK, so the RT9013 (if fitted) is highly optimised for the purpose of dropping 5 V and 5 V only to 3.3 V - low drop-out, low quiescent current and 800 mA peak current.

The RT9013 max. input voltage is 5.5V. Won't do well at 12V.

Other WeMOS editions may use a different regulator of course, there are regulators with 3.3V output that take like 15V maximum on the input. Overheating is definitely a concern with such great voltage drops.