Arduino, running the sketch you wrote
arduino-cli compiles it, an AVR8 core executes it instruction by instruction, and the LCD shows what the ATmega328P actually put on the bus. Uno, Nano, Mega and ATtiny85, no board on your desk.

Hardware is all about iteration. Velxio lets you wire a circuit, program the board and run it in seconds, real firmware on a real solver, right in the browser.
DFRobot · M5Stack links on this page are affiliate links: a purchase through them earns Velxio a small commission at no extra cost to you.
Nothing on this page is a scripted animation: the firmware is compiled and executed, and the circuit around it is solved.
arduino-cli compiles it, an AVR8 core executes it instruction by instruction, and the LCD shows what the ATmega328P actually put on the bus. Uno, Nano, Mega and ATtiny85, no board on your desk.

arduino-cli or ESP-IDF compiles the sketch, then AVR8, RP2040, RISC-V, Xtensa or ARM executes it instruction by instruction. What the OLED draws and what the serial monitor prints is what the chip actually did.

ngspice compiled to WebAssembly runs a full nodal analysis about 60 times a second. GPIO pins drive real nets, ADC inputs read solved node voltages, and probes report RMS, DC and current wherever you drop them.

Adders, comparators, decoders, flip-flops and a 1-bit ALU slice: no microcontroller anywhere, just gates, switches and LEDs solved as a real net. The classroom half of electronics, without the breadboard.

The M5Stack Cardputer with its keyboard, Seeed's round display keeping time, Pimoroni's Badger 2350 driving e-paper, and DFRobot's UNIHIKER M10 in the catalogue alongside them. Their makers sent the hardware so the emulation could be checked against the real thing.




35 boards across 6 CPU architectures — AVR8, ARM Cortex-M, ARM Cortex-A, RISC-V, Xtensa, and Linux. Including partner boards from Pimoroni, M5Stack, Seeed Studio and DFRobot. All running locally, no cloud needed.
One institution contract gives every student in the class a full Pro account. No per-seat checkout, no card details in a classroom.
Private projects, BOM and schematic exports, GitHub Sync and the offline desktop app, for everyone enrolled.
Billed once to your institution, per semester or per year. Volume pricing on request for large cohorts.
Arduino, ESP32, RP2040, STM32, ATtiny and Raspberry Pi, with SPICE analog solved alongside the firmware. Not a sandboxed mock.
The simulator stays free forever. Paid plans unlock the Linux and STM32 boards, WiFi and the offline desktop app. Maker and Pro add the AI agent; No AI leaves it out.
Discover the simulator + light AI help.
The full workbench, zero AI. You write every line.
For makers shipping real circuits with AI help.
Private projects, GitHub Sync and BOM exports.
Questions, bugs and ideas: the Discord and the issue tracker are open, and so is every line of the simulator.
An interactive Arduino Uno circuit simulation you can run free in your browser on Velxio, by kiybiy36.
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <SPI.h>
#include <Wire.h>
#include <avr/pgmspace.h>
// --- Konfigurasi Dasar ---
// Pengaturan layar OLED (128x64 piksel)
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1 // Pin reset OLED (-1 jika tidak menggunakan pin reset khusus)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
// Pin Joystick
#define JOY_HORZ A0 // Pin analog untuk sumbu horizontal joystick
#define JOY_VERT A1 // Pin analog untuk sumbu vertikal joystick
#define JOY_SEL 2 // Pin digital untuk tombol select joystick (biasanya D2)
// Nilai tengah pembacaan ADC joystick (sekitar 512 untuk 10-bit ADC)
const int ADC_MIDPOINT = 512;
// Ambang batas untuk deteksi gerakan joystick (mengurangi sensitivitas)
const int JOY_THRESHOLD = 100;
// Waktu tunda untuk debounce input (mencegah pembacaan ganda saat tombol ditekan)
const int INPUT_DEBOUNCE_DELAY = 200; // ms
// Waktu tunda untuk splash screen di awal
const int SPLASH_SCREEN_DELAY = 2000; // ms
// Posisi teks untuk layar Game Over
const int GAME_OVER_POS_X = 20;
const int GAME_OVER_TEXT_Y = 20;
const int GAME_OVER_SCORE_Y = 30;
const int GAME_OVER_ACTION_Y = 40;
// --- Struktur Data Menu ---
// Teks item menu disimpan di PROGMEM untuk menghemat SRAM.
// PROGMEM adalah area memori flash Arduino tempat data konstan dapat disimpan.
const char menuItem0[] PROGMEM = "Brick Breaker";
const char menuItem1[] PROGMEM = "Space Invaders";
const char menuItem2[] PROGMEM = "Snake";
const char menuItem3[] PROGMEM = "Flappy Bird";
const char menuItem4[] PROGMEM = "Dino Run";
// Array pointer ke string menu, juga di PROGMEM.
const char *const menuItems[] PROGMEM = {menuItem0, menuItem1, menuItem2, menuItem3, menuItem4};
const int TOTAL_MENU_ITEMS = 5;
// --- Status Game Global ---
// Enum untuk merepresentasikan berbagai status game, lebih mudah dibaca daripada angka.
enum GameStateType
{
STATE_MENU,
STATE_BRICK_BREAKER,
STATE_SPACE_INVADERS,
STATE_SNAKE,
STATE_FLAPPY_BIRD,
STATE_DINO_RUN
};
GameStateType currentGameState = STATE_MENU; // Status game saat ini, dimulai dari menu.
int menuSelection = 0; // Pilihan menu saat ini (0 hingga TOTAL_MENU_ITEMS - 1).
int score = 0; // Skor pemain saat ini.
bool gameOver = false; // Status apakah game sedang berakhir (true) atau tidak (false).
// --- Variabel Game: Brick Breaker ---
#define BRICK_ROWS 3
#define BRICK_COLS 8
#define BRICK_WIDTH 16
#define BRICK_HEIGHT 6
bool bricks[BRICK_ROWS][BRICK_COLS]; // Array 2D untuk status setiap bata.
int paddleX = SCREEN_WIDTH / 2 - 15; // Posisi X paddle.
const int paddleY = SCREEN_HEIGHT - 4; // Posisi Y paddle (tetap).
const int paddleWidth = 30;
const int paddleHeight = 4;
float ballX = SCREEN_WIDTH / 2; // Posisi X bola.
float ballY = SCREEN_HEIGHT - 10; // Posisi Y bola.
float ballVelX = 2; // Kecepatan horizontal bola.
float ballVelY