WEMOS D1 MINI ESP32

Development Board D1_MINI32

WEMOS D1 MINI ESP32 is a development board based on the ESP32 microcontroller using XTENSA architecture.

This board features a maximum CPU frequency of 240 MHz and 4MB flash memory.

240 MHz CPU 4MB Flash WiFi + BT 4.2 31 × 39 mm ~6$ per unit

About WEMOS D1 MINI ESP32

ESP32 Xtensa dual-core 32-bit LX6 · 240 MHz

The WEMOS D1 mini ESP32 squeezes Espressif’s dual-core ESP32-WROOM-32 module into the familiar 34 × 25 mm D1-mini footprint-so it drops straight into the huge ecosystem of D1-mini shields. Despite its tiny size it brings full-featured Wi-Fi 802.11 b/g/n and Bluetooth 4.2 (BLE + BR/EDR) connectivity to your IoT projects. 📡

A reliable CH340C USB-to-UART interface (auto-reset capable) lets you plug in via Micro-USB, flash code, and get serial logs with zero extra hardware. 🔌

Power is flexible: feed the board from 5 V on USB/VIN or directly from the regulated 3V3 pin. An on-board LDO and protective circuitry keep the ESP32 happy. ⚡️

The board sports a tiny PCB antenna for solid RF performance, plus RST and BOOT (IO0) push-buttons to simplify firmware flashing and recovery. 🚀

All GPIOs support PWM, many provide ADC, DAC, I²C, SPI, UART, and ten pads double as capacitive-touch sensors. Stack it beneath sensor, relay, or display shields and you’ve got a compact yet powerful connected gadget in minutes. ⚙️

Where to Buy WEMOS D1 MINI ESP32

Starting from

6$ per unit

Amazon.com Ships worldwide

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Amazon.de Ships to EU

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AliExpress Best value

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Prices are subject to change. We earn from qualifying purchases as an Amazon Associate.

Technical Specifications

Complete technical specification details for WEMOS D1 MINI ESP32

ESP32 · Dual-Core

Arch

XTENSA

Clock

240 MHz

Flash

4MB

Connectivity

WiFi

802.11 b/g/n (2.4 GHz)

Bluetooth 4.2

Classic + BLE

Digital IO

Analog In

Size: 39 mm x 31.5 mmWeight: 12GBuilt-in PCB antennaOperating voltage: 5V DC

Full datasheet & reference manual

Download

Quick Setup

Copy-paste configs for WEMOS D1 MINI ESP32 - auto‑generated from this board's exact hardware specs.

ESP32 240 MHz 4MB DIO Xtensa

In Arduino IDE 2 select D1 Mini32 from the esp32 by Espressif package. In PlatformIO use board = esp32dev. ESP32 · 240 MHz · 4MB · DIO.

Tools menu settings

Board (select in Arduino IDE) D1 Mini32

CPU Frequency 240 MHz

Flash Size 4MB

Flash Mode DIO

Upload Speed 921600

Architecture Xtensa

In Arduino IDE 2, open Boards Manager, search "esp32" by Espressif and install it. Then go to Tools → Board and select "D1 Mini32" for the WEMOS D1 MINI ESP32.

platformio.ini


[env:d1_mini32]
platform  = espressif32
board     = esp32dev
framework = arduino

; Exact hardware config for WEMOS D1 MINI ESP32
board_build.mcu        = esp32
board_build.f_cpu      = 240000000L
board_build.flash_size = 4MB
board_build.flash_mode = dio
board_upload.flash_size = 4MB

The board value is a close generic match - check PlatformIO board registry for an exact fit.

esp32: block (YAML)


esp32:
  board: esp32dev
  framework:
    type: arduino   # or "esp-idf"

# WEMOS D1 MINI ESP32 - 240 MHz ESP32
# Flash: 4MB | USB: N/A

Paste into your device's .yaml. See ESPHome ESP32 docs for full options.

esptool.py - flash command


esptool.py \
  --chip esp32 \
  --baud 921600 \
  write_flash \
    --flash_mode dio \
    --flash_size 4MB \
    0x1000 bootloader.bin \
    0x8000    partitions.bin \
    0xe000    boot_app0.bin \
    0x10000   firmware.bin

Install: pip install esptool - replace firmware.bin with your binary - bootloader at 0x1000

WEMOS D1 MINI ESP32 Board Dimensions

Physical measurements for WEMOS D1 MINI ESP32

WEMOS D1 MINI ESP32 dimensions - height, width

Width 31mm

Length 39mm

Pin Gap 2.54mm

WEMOS D1 MINI ESP32 Pinout Diagram

Complete pin reference for WEMOS D1 MINI ESP32

The WEMOS D1 mini ESP32 pinout exposes 26 ESP32 GPIOs on the familiar D label headers-making it shield-compatible while retaining the ESP32’s rich peripherals.

Power rails include 5 V/VIN (USB or external), a regulated 3V3 output, and multiple GND pins. Current draw is typically 80 mA active but can drop to <10 µA in deep-sleep.

Default serial lines U0_TX (GPIO1) and U0_RX (GPIO3) connect to the CH340C for programming and logging. Need another UART? Use U2_TX (GPIO17) and U2_RX (GPIO16).

I²C defaults to SDA (GPIO21) and SCL (GPIO22)-changeable in software-and breaks out on the D2/D1 shield pins.

SPI: the primary VSPI bus maps to MOSI GPIO23, MISO GPIO19, SCK GPIO18, and CS GPIO5. An alternate HSPI bus lives on GPIO12–15 when a second SPI device is needed.

Analog: Eight ADC1 channels on GPIO32–GPIO39 remain usable while Wi-Fi is active. Extra ADC2 channels (e.g., GPIO0, 2, 4, 12–15, 25–27) share hardware with Wi-Fi. Dual 8-bit DAC outputs are on GPIO25 and GPIO26.

Capacitive-touch sensing is available on GPIO0, 2, 4, 12–15, 27, 32, 33, perfect for touch-buttons or gesture pads.

Every GPIO can generate PWM up to 40 kHz for LEDs, motors, or buzzers. Watch the boot-strap pins-GPIO0, GPIO2, and GPIO15-which must be at the correct logic level (usually HIGH) at reset to boot normally.

With breadboard-friendly headers, shield compatibility, and the full might of an ESP32 module, the WEMOS D1 mini ESP32 pinout is your compact gateway to advanced connected projects.

Safe Pins to Use

These pins are safe for general GPIO usage without boot or system conflicts.

LED_BUILTIN TXD RXD SDA SCL SS MOSI MISO SCK A0 A3 A4 A5 DAC1 DAC2 IO27 RX2 TX2 BOOT_IO0 A6 A7

✓ No boot sequence involvement

✓ No flash/PSRAM connections

✓ No USB or JTAG conflicts

✓ Freely assignable without issues

Pins to Avoid or Use with Caution

Reserved for critical functions. Misuse may cause boot failures, programming issues, or system conflicts.

Strapping JTAG USB Flash/SPI UART

Pin	Label	Why Avoid	Type
IO14	MTMS (GPIO14)	Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.	🪛 Other
IO12	MTDI (GPIO12)	Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.	🛠️ Strapping
IO13	MTCK (GPIO13)	Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.	🪛 Other
IO15	MTDO (GPIO15)	Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.	🛠️ Strapping
IO4	GPIO4	Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).	🛠️ Strapping

Useful Links

Datasheets and resources for WEMOS D1 MINI ESP32

Board Datasheet

Technical specifications

ESP32 Datasheet

Microcontroller reference

WEMOS D1 MINI ESP32 Custom Pin Mapping

Pin configuration and GPIO mapping for WEMOS D1 MINI ESP32

Digital I/O Pins

Interrupt Pins

Analog Inputs

Pin	Function	ESP Pin	I/O Type	Description
1	LED_BUILTIN	GPIO2	output	On-board blue LED (active-LOW)
2	TXD	GPIO3	output	UART0 Transmit (U0_TX)
3	RXD	GPIO1	input	UART0 Receive (U0_RX)
4	SDA	GPIO21	bidirectional	I²C Data Line
5	SCL	GPIO22	bidirectional	I²C Clock Line
6	SS	GPIO5	bidirectional	VSPI Chip-Select
7	MOSI	GPIO23	bidirectional	VSPI Master-Out Slave-In
8	MISO	GPIO19	bidirectional	VSPI Master-In Slave-Out
9	SCK	GPIO18	bidirectional	VSPI Clock
10	A0	GPIO36	input	ADC1 Channel 0
11	A3	GPIO39	input	ADC1 Channel 3
12	A4	GPIO32	input	ADC1 Channel 4 / Touch 9
13	A5	GPIO33	input	ADC1 Channel 5 / Touch 8
14	DAC1	GPIO25	output	8-bit Digital-to-Analog Converter 1
15	DAC2	GPIO26	output	8-bit Digital-to-Analog Converter 2
16	IO27	GPIO27	bidirectional	Touch 7 / RTC-17
17	IO14	GPIO14	bidirectional	HSPI SCK / Touch 6
18	IO12	GPIO12	bidirectional	HSPI MISO / Touch 5
19	IO13	GPIO13	bidirectional	HSPI MOSI / Touch 4
20	IO15	GPIO15	bidirectional	Boot-strap Pin / Touch 3
21	IO4	GPIO4	bidirectional	Touch 0 / ADC2 Channel 0
22	RX2	GPIO16	bidirectional	UART2 Receive
23	TX2	GPIO17	bidirectional	UART2 Transmit
24	BOOT_IO0	GPIO0	bidirectional	Boot-mode Select / Touch 1 (keep HIGH to boot)
25	A6	GPIO34	input	ADC1 Channel 6 (input-only)
26	A7	GPIO35	input	ADC1 Channel 7 (input-only)

Legend

Function Pin role

GPIO ESP32 pin

I/O Direction

# Pin number

Pin Mappings

Complete pinout and GPIO mapping for WEMOS D1 MINI ESP32

Digital I/O Pins

Interrupt Pins

Analog Inputs

Pin	Analog	Touch	PWM	Other
1				TXD
2				LED_BUILTIN
3				RXD
5
16
17
18
19
21
22
23
26
35				_VBAT

Legend

A0 Analog input

T0 Touch sensor

PWM PWM capable

RX/TX Serial pins

LED Built-in LED

# Pin number

Default Tools & Configuration

Build and upload settings for WEMOS D1 MINI ESP32

Setting	Value
Bootloader tool	esptool_py
Uploader tool	esptool_py
Network uploader tool	esp_ota
Bootloader address	`0x1000`
Flash mode	dio
Boot mode	dio
Maximum upload size	1280 KB (1310720 bytes)
Maximum data size	320 KB (327680 bytes)

Configuration Summary

The WEMOS D1 MINI ESP32 uses esptool_py for uploads , esp_ota for OTA updates, and esptool_py bootloader at 0x1000.

Flash mode: dio | Boot mode: dio

Max sketch size: 1280 KB | Max data size: 320 KB

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WEMOS D1 MINI ESP32

About WEMOS D1 MINI ESP32

Where to Buy WEMOS D1 MINI ESP32

Technical Specifications

Quick Setup

WEMOS D1 MINI ESP32 Board Dimensions

WEMOS D1 MINI ESP32 Pinout Diagram

Safe Pins to Use

Pins to Avoid or Use with Caution

Useful Links

WEMOS D1 MINI ESP32 Custom Pin Mapping

Pin Mappings

Default Tools & Configuration

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Contents