Last Updated on 15 April 2022 by Suffocation

The WEMOS D1 EP32 is the replacement for the D1 Mini. It has a vapor-deposited ESP 32 Wroom module. A USB Micro connector, a reset button, and two built-in LEDs on the ESP are the only peripherals. It's relatively small in terms of dimensions, but this does not limit the number of external pins, which are led outwards in two rows.

Interesting, how with the Wemos D1 Mini there are so many expansion boardsSee manufacturer).

I haven't found any information about the D1 ESP32 on Wemos, so I question whether it is officially produced by Wemos.

Facts

USB Micro Connector (CH9102)
Reset button
18 Digital Pins
8 Analogue Pins (almost freely configurable)
Operating voltage 3.3V
Connection voltage 5V
4M SPI Flash Memory
80MHz/240MHz
2 LEDs
Price ~€5
Dimensions in mm: l/w/h 39/32/13

Pin assignment

Pin	Functions	ESP32 Pin
TX	UART TXD	TXD
RX	UART RXD	RXD
A0	IO, ADC2	GPIO36
D0	In	GPIO26
D1	In	GPIO22, I²C SCL
D2	In	GPIO21, I²C SDA
D3	In	GPIO17
D4	In	GPIO16
D5	In	GPIO18
D6	In	GPIO19
D7	In	GPIO23
D8	In	GPIO5
G	Ground	Ground
5V	5V	–
3V3	3.3V	3.3V
RST	Reset	RST

Source: https://www.wemos.cc/en/latest/d1/d1_mini.html

Areas of application

Microcontroller projects with Wi-Fi
Remote control
Alarm clock
...

Views

Programming

Preparation

The Wemos comes with a CH9102 USB interface; if the driver is not already installed, it will need to be installed afterwards.

CH9102 USB Driver

Libraries

No additional libraries are required for programming the Wemos. However, the ESP extension for the Arduino GUI must be installed. See also the Link for setup.

Current status Arduino ESP32 Library V2.0.2

Test programme

Blink can be used as a test program. This is available either in the example programs of the Arduino GUI, under which you will also find the task-controlled Blink, which is quite useful for learning the multitask environment on the ESP32. This can also be obtained via Github:

https://github.com/espressif/arduino-esp32/blob/master/libraries/ESP32/examples/FreeRTOS/FreeRTOS.ino

I was able to program my Wemos D1 ESP32 with the following settings:

As the port, please select your serial interface; for me, it's COM 15.

Problems

D Ports not found

Unfortunately, the D-ports are not mapped. Here, it helps to simply create defines with the corresponding ports. Example:

#ifndef D7
#define D7 23
#endif

#ifndef D5
#define D5 18
#endif

Wemos board not recognised

CH9102 Install drivers

Should there be any further problems Zadig Try.

Programming fails

Check board, port and programmer settings. Possibly try others than the ones I showed. There are also board settings for the Wemos.

Miscellaneous

Fritzing Wemos D1 ESP32 Mini:

https://forum.fritzing.org/uploads/short-url/wv8xVt6y4tFToPngAeMqUju2oUl.fzpz

Example projects:
https://github.com/wemos/D1_mini_Examples

3D printing model
https://grabcad.com/library/wemos-d1-mini-v3-0-0-1

https://grabcad.com/library/wemos-d1-mini-1

Conclusion

In my opinion, the D1 ESP32 is not entirely compatible as I couldn't find a board description for the Arduino GUI that also included the mapping for the D-ports. Nevertheless, it can serve as a speedy replacement. Due to the additional pins, it is also well-suited for other projects. With the pass-through ports, it can also be operated on a breadboard and is very compact overall.

Sources

ESP Wroom 32 Datasheet

https://arduino-projekte.info/produkt/d1-mini-esp32-wifi-bluetooth/