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, WiFi with internet included. Paid plans unlock the Linux and STM32 boards, custom WiFi networks, the local network gateway 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 Aitewinrobot Esp32C3 Supermini circuit simulation you can run free in your browser on Velxio, by vup129623.
#include <Arduino.h>
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <math.h>
// =====================================================
// ESP32-C3 + ILI9341 320x240 - GAME CENTER (FULL 5 GAMES)
// TAI XIU + QUAY HU + CANH CUT + XOC DIA + VONG QUAY
// =====================================================
#define TFT_SCK 4
#define TFT_MOSI 6
#define TFT_CS 7
#define TFT_DC 2
#define TFT_RST 10
#define BTN_UP 0
#define BTN_DOWN 1
#define BTN_A 3
#define BTN_B 8
#define BTN_C 9
#define BTN_EXIT 21
Adafruit_ILI9341 tft(TFT_CS, TFT_DC, TFT_RST);
// Bộ đệm vẽ dùng cho Vòng Quay (Canvas)
GFXcanvas16 canvas(320, 70);
// =====================================================
// ENUM
// =====================================================
enum ButtonId { BID_UP, BID_DOWN, BID_A, BID_B, BID_C, BID_EXIT, BUTTON_COUNT };
enum AppState { START_BALANCE, GAME_MENU, PLAY_TAIXIU, PLAY_SLOT, PLAY_PENGUIN, PLAY_XOCDIA, PLAY_WHEEL };
enum BQPhase { BQ_IDLE, BQ_PLAYING, BQ_JUMPING, BQ_LANDING, BQ_BREAKING, BQ_FALLING, BQ_RESULT };
enum XDPhase { XD_IDLE, XD_SHAKING, XD_OPENING, XD_RESULT };
enum WWPhase { WW_IDLE, WW_SPINNING, WW_RESULT };
AppState appState = START_BALANCE;
BQPhase bqPhase = BQ_IDLE;
XDPhase xdPhase = XD_IDLE;
WWPhase wwPhase = WW_IDLE;
// =====================================================
// MÀU SẮC
// =====================================================
#define BG 0x0000
#define PANEL_DK 0x18C3
#define WHITE 0xFFFF
#define GRAY_LT 0xC618
#define GRAY 0x8410
#define GRAY_DK 0x4208
#define BLACK 0x0000
#define YELLOW 0xFFE0
#define RED 0xF800
#define RED_DK 0x8000
#define GREEN 0x07E0
#define GREEN_LT 0x87F0
#define GOLD 0xFEA0
#define GOLD_DK 0xC800
#define GOLD_LT 0xFFF0
#define ORANGE 0xFD20
#define CYAN 0x07FF
#define CYAN_DK 0x0450
#define CYAN_LT 0x87FF
#define ICE_FILL 0x059F
#define ICE_BORDER 0xAEFF
#define ICE_SHADOW 0x02B5
#define ICE_CRACK 0x0210
#define C_1 0xE820 // Đỏ thẫm
#define C_2 0x033F // Xanh dương
#define C_3 0x0400 // Xanh lá
#define C_4 0xFC00 // Cam
#define C_5 0x8010 // Tím
// =====================================================
// LAYOUT CHUNG
// =====================================================
#define SCREEN_W 320
#define SCREEN_H 240
#define HEADER_H 26
#define CENTER_X 160
// Tài Xỉu
#define TX_CAU_SIZE 24
// Slot
#define CARD_W 58
#define CARD_H 96
#define CARD_GAP 5
#define CARD_Y 32
#define CARD_COUNT 5
// Penguin
const int POS_COUNT = 15;
const float bqMult[POS_COUNT] = {0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 7.5, 10.0, 12.5, 20.0, 30.0, 50.0};
const long bqMultX10[POS_COUNT] = {0, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100, 125, 200, 300, 500};
const int BLOCK_W = 54;
const int BLOCK_H = 40;
const int STEP = BLOCK_W + 4;
const int BLOCK_Y = 135;
const int JUMP_