Supported Hardware

Boards

Circzy supports eleven boards from five families. Every board is compiled with its official Arduino core and simulated by an emulator for its microcontroller.

Arduino UnoATmega328P · The most popular board for learning Arduino.
Arduino NanoATmega328P · Like the Uno, but small enough to fit on a breadboard.
Arduino Mega 2560ATmega2560 · Lots of pins for big projects.
Raspberry Pi PicoRP2040 · Dual-core ARM 133 MHz, 26 pin GPIO, 3.3 V.
STM32 Blue PillSTM32F103C8 · ARM Cortex-M3 72 MHz, 32 pin GPIO, 3.3 V.
ESP32 DevKit V1ESP32-WROOM-32 · Dual-core Xtensa 240 MHz, WiFi & Bluetooth, 3.3 V.
WEMOS D1 Mini ESP32ESP32-WROOM-32 · ESP32 in the D1 mini size, two pin rows on each side, WiFi & Bluetooth.
WEMOS D1 R32ESP32-WROOM-32 · ESP32 in the Arduino Uno form factor, fits Uno shields.
NodeMCU V3 (LoLin)ESP8266 (ESP-12E) · The most common ESP8266 board, WiFi, 11 GPIO pins, 3.3 V.
NodeMCU Amica (V2)ESP8266 (ESP-12E) · Slim NodeMCU that fits on a breadboard, WiFi, 3.3 V.
WEMOS D1 MiniESP8266EX · Tiny ESP8266 board, WiFi, 11 GPIO pins, 3.3 V.

Family	Emulator	Arduino core
Arduino (AVR)	avr8js, ATmega328P and ATmega2560	Arduino AVR Boards
ESP32	Xtensa LX6 emulator compiled to WebAssembly	arduino-esp32 3.3.10
ESP8266	Xtensa LX106 emulator (esp8266js, extended for Circzy)	ESP8266 Arduino core 3.1.2
Raspberry Pi Pico	rp2040js	Arduino-Pico (Earle Philhower)
STM32	Built-in Cortex-M3 emulator	STM32duino 2.12.0

Each family has its own page with pin tables and notes: Arduino, ESP32, ESP8266, Raspberry Pi Pico and STM32.

Parts

More than 100 parts are available in the Components panel. They are grouped into categories:

Open any category in the Parts Reference to see each part's picture, pins, wiring hint and simulation behavior.

Simulated peripherals

Peripheral	Notes
GPIO	Digital input and output with pull-ups, on every board.
Interrupts	`attachInterrupt()` on the pins that support it on each board.
ADC	`analogRead()` with the resolution of each board (10-bit on AVR, ESP8266 and STM32 by default, 12-bit on ESP32, Pico configurable).
PWM	`analogWrite()`, ESP32 LEDC and Pico PWM slices.
Timers	`millis()`, `micros()`, `delay()`, `tone()`, Servo, hardware timers.
UART	`Serial` to the Serial Monitor, extra hardware serial ports, and SoftwareSerial where the core provides it.
I²C	`Wire` for displays, sensors, RTC and port expanders.
SPI	`SPI` for SD cards, RFID, TFT displays and MAX7219.
Non-volatile storage	`EEPROM` on ESP8266 and `Preferences` on ESP32 (kept while the simulation runs).
RMT / PIO	NeoPixel timing on ESP32 (RMT) and Pico.

ESP WiFi and Bluetooth connect to the Circzy virtual network and can be tried with the virtual phone. See WiFi & Virtual Phone.

Ready to try it?

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