Brian Lough

D1 Mini Breakout Board

A board I wish I made a year ago!

This is a board that breaks out the pins of the Wemos D1 Mini ESP8266 board to screw terminals, has a prototype area and a barrel jack connector for projects that need more amps than can be supplied via USB.

I wanted to make this board because I found myself making a similar style board out of perf-board a lot, where I would breakout some of the pins of the Wemos to screw terminals, add a DC jack and add a small bit of other circuitry.

These are now available on my Tindie store!

Additional Parts Required

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Board Assembly

To assemble the boards, place the parts on the PCB as indicated by the markings on the PCB. All parts are places on the top of the PCB. Pay attention to the polarity of the capacitor and the diode when assembling.

The Red and Black screw terminals are intended to be placed in the dedicated 5v and GND terminals blocks.

Read the below section for details on where to place the jumper block.

Powering the D1 Mini Breakout Shield

Please note that the DC jack is center positive and 5V only (sort of)

The jumper block Controls the power going to or coming from the D1 Mini:

  • Occupying the two pins on the right (as shown in the photo above), the Wemos will receive 5V power from the Barrel Jack, but the wemos will not power and of the 5v pads as it is going through a diode. This is useful for large current draw projects such as Neopixel displays
  • Occupying the two pins on the left (marked "Diode bypass"), will bypass the diode so the 5V pads will now receive power from the D1 Mini's 5v pin via the micro USB port. This is useful for lower current draw projects.
  • Removing the block separates the D1 Mini's power pins from the rest of the PCB.

Is the Barrel Jack really 5V only?

For simplicity sake, I say it is, as the D1 Mini regulator can only handle up to 5.5V. BUT it is possible to use it with higher voltages if you remove the jumper from the pins and provide power to the D1 mini some other way (either a voltage regulator to any of the 3.3v pins on the proto-area or using the micro USB on the D1 mini). All pads and screw terminals on the board labeled "5V" would then become VIN from the DC jack, the only exception to this is the 5v pin of the D1 mini and the pin immediately inside it.