Wemos D1 mini simulator, the ESP8266 made small
The D1 mini is the NodeMCU’s ESP8266, on an ESP-12F module, on a board a third the size. The same D0 to D8 names mean the same GPIOs, the blue LED on D4 lights when the pin is LOW, and WiFi joins a simulated network.
- 6peripheral areas modeled
- 1project ready to run
- Real timeon your own machine
What is modeled
Taken from the board's own contract document and put in plain words, with what is missing beside it.
Modeled
- Core
- The Xtensa LX106 at 80 MHz, in the call0 ABI
- GPIO
- Every pin the board brings out, with D0 to D8 named the NodeMCU’s way
- A0
- Behind the board’s 220k and 100k divider, so the hole reads 0 to about 3.2 V
- UART0
- Wired to the serial monitor
- WiFi, simulated
- The Arduino WiFi calls over a network written in software: no radio, no 802.11, no real internet
- The board
- Two rows of eight, 0.9 inch apart, and the blue LED on D4
Not modeled
- The CH340 USB-serial chip, the USB reset circuit and deep sleep’s wake from D0.
- A radio of any kind.
Open one and press Run
Each of these opens in the editor exactly as it is drawn here.
Every built-in project on the D1 mini
Each has its own page with the circuit running, the code and a parts list.
Tutorials that use this board
Each one ends in a running circuit, on this same board.
Questions
Is it free?
Yes. Every board and every part is on the free plan, with no account needed.
Can I compile my own sketch?
Yes. Its processor is an Xtensa LX106, the NodeMCU’s chip, and your sketch compiles in the tab the same way: edit it and press Run.
Is D1 GPIO 1?
No. D1 is GPIO 5, D2 is GPIO 4 and D4 is GPIO 2: the silkscreen names are the NodeMCU’s, not GPIO numbers.
Does it simulate WiFi?
Yes, and it says so. The board joins a network written in software, with the name and password as settings on the board. There is no radio and no real internet.
The other boards
Every one of these runs today, and every one is free.
A RISC-V chip at 160 MHz, on the real memory map.
The classic Arduino, with an ATmega328P running at 16 MHz.
The Uno’s chip on a small board that fits a breadboard.
The big Arduino, with 54 digital pins and four serial ports.
An Uno-shaped board whose chip does its own USB serial.
A second RISC-V board, with 31 pins and simulated WiFi.
The classic ESP32 at 240 MHz, with simulated WiFi.
The ESP32-S3 at 240 MHz, with USB serial and an RGB LED.
Try it on your own firmware
What you build here runs on the board on your desk, unchanged. Nothing to install and no account needed.