D1 Mini Boards (ESP8266 and ESP32)

There are many different mini boards available with differend ESP processors that share the same form factor and connector pin assignments.

The D1 mini format for boards and shield was created by the wemos.cc company and is a good base for starting with DIY devices.

There are many different mini boards available also with differend ESP processors. They all share the position of 2 connectors with 8 pins that are compatible to a certain degree and can be combined with the available shields.

The ESP8266 versions have been out first offering

11 digital input/output pins
1 analog input(3.2V max input)
3V3, 5V, GND and RST are always in the same position
RST momentary button

Some boards offer i2c connectors.

ESP8266 based boards

D1 mini ESP8266

D1 mini ESP8266 board

The D1 mini boards use a ESP8266 MCU and 4 MByte flash memory chip.

A board configuration (env.json)

{
  "device": {
    "0": {
      "name": "d1mini",
      "title": "D1 mini",
      "loglevel": 2,
      "description": "D1 mini board with ESP8266",
      "logfile": 1,
      "safemode": "false",
      "homepage": "/index.htm",
      "led": "D4",
      "cache": "etag"
    }
  },
  "ota": {
    "0": { }
  },
  "ntptime": {
    "0": {
      "zone": "CET-1CEST,M3.5.0,M10.5.0/3"
    }
  }
}

D1 mini V4

The D1 mini board labeld with v4 uses a ESP8266 MCU and 4 MByte flash memory chip and includes:

USB-C connector
i2c connector using the Qwiic standard JST SH 4-pin (1mm)

D1 mini pro

The D1 mini pro board is based on the ESP8266 MCU and 4 MByte flash memory chip and includes:

Built-in PCB antenna or External antenna connector
Lithium battery interface, 500mA Max charging current with a PH 2.0 connector
i2c connector using the Qwiic standard JST SH 4-pin (1mm)
RST and GPIO16 can be connected using a solder spot on the back to support deep sleep mode.

Pins for ESP8266 boards

All the ESP8266 based boards above use the same pin assignments and are interchangeable. The 2 connectors with 8 pins have the following ports assigned in the ESP8266.

d1mini pins

ESP32 based boards

There are some ESP32 based boards that use the same form factor but may not be completely compatible.

D1 mini ESP32

A similar D1 mini ESP32 board exists using a ESP32 MCU and 4 MByte flash memory chip.

/boards/esp32/d1miniesp32.jpg

D1 mini ESP32-C3

Board C3 Mini

This is D1 mini compatible board based on the EPS32-C3 MCU.

Board C3 pico

The C3 pico is a board compatible to the D1 Mini boards and shields using a ESP32-C3 processor and equipped with some special features like a RGB LED, I2C Port and LiPo charging.

Shields

There are some shields for the board form-factor available. Here some examples:

The D1 Mini 8x8 RGB Shield has 64 WS2812 LEDs that can be addressed using the Neo Element.

The data signal for the chain of WS2812 LEDs is bound to D4.

The WS2812 leds use "config": "rgb".

This is a shield you can use to create and apply special configurations by soldering components on the free grid.

The SHT30 shield with a digital temperature and humidity sensor can be stacked upon a board or can be attached by using a Qwiic connector cable.

The D1-Mini SD Card shield adds a sd card slot for min sd cards to the standard SPI bus.

The CS assignment can be changed on the back of the shield by cutting the default (D4) wiring and soldering a bridge for another pin.

The SD18B20 Shield has a Dallas / DS18B20 sensor that can be used with the Dallas Element to retrieve the local temperature.

The Data pin of the sensor is connected to D2.

The Buzzer Shield has a passive speaker that can be used with the Tone Element to make some noise.

The buzzer can be connected to various pins by closing one of the solder pads.