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.
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Private projects, BOM and schematic exports, GitHub Sync and the offline desktop app, for everyone enrolled.
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Arduino, ESP32, RP2040, STM32, ATtiny and Raspberry Pi, with SPICE analog solved alongside the firmware. Not a sandboxed mock.
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Questions, bugs and ideas: the Discord and the issue tracker are open, and so is every line of the simulator.
An interactive Esp32 Devkit C V4 circuit simulation you can run free in your browser on Velxio, by std2401043.
#include <Wire.h>
// Dirección I2C del driver (0x0F)
#define MOTOR_DRIVER_ADDR 0x0F
#define MOTOR_SPEED_SET 0x82
#define DIRECTION_SET 0xAA
// Pines asignados según tu circuito visual
const int PIN_BOTON_VERDE = 18; // SIG1 (Cable verde)
const int PIN_BOTON_ROJO = 5; // SIG2 (Cable morado)
// Declaración de funciones
void ejecutarSecuenciaPrueba();
void enviarComandoMotor(uint8_t canal, uint8_t velocidad, bool sentidoHorario);
void detenerMotores();
bool verificarParoEmergencia(int milisegundosEspera);
void setup() {
Serial.begin(115200);
// Configuración de los pines del botón doble Grove
pinMode(PIN_BOTON_VERDE, INPUT);
pinMode(PIN_BOTON_ROJO, INPUT);
// Inicialización de I2C en pines ESP32 (SDA = 21, SCL = 22)
Wire.begin(21, 22);
delay(500);
Serial.println("--- CIRCUITO LISTO EN ESPERA DEL BOTÓN GROVE ---");
detenerMotores();
}
void loop() {
// El circuito se queda esperando a que presiones el Botón Verde
if (digitalRead(PIN_BOTON_VERDE) == HIGH) {
Serial.println("-> Botón Verde presionado: Iniciando secuencia de motores...");
ejecutarSecuenciaPrueba();
Serial.println("-> Secuencia finalizada. Esperando nueva pulsación...");
delay(500); // Antirrebote al terminar
}
// Si presionas el botón rojo estando en reposo, asegura el apagado
if (digitalRead(PIN_BOTON_ROJO) == HIGH) {
detenerMotores();
}
}
/**
* Ejecuta exactamente la secuencia que enviaste en tu código,
* comprobando en cada paso si se pulsa el botón rojo para detenerse.
*/
void ejecutarSecuenciaPrueba() {
// 1. Probar Canal M1 (Motor Superior Izquierdo)
Serial.println("1. Probando Canal M1 (Superior Izquierdo)...");
enviarComandoMotor(1, 180, true);
if (verificarParoEmergencia(2000)) return;
detenerMotores();
if (verificarParoEmergencia(1000)) return;
// 2. Probar Canal M2 (Motor Inferior Izquierdo)
Serial.println("2. Probando Canal M2 (Inferior Izquierdo)...");
enviarComandoMotor(2, 180, true);
if (verificarParoEmergencia(2000)) return;
detenerMotores();
if (verificarParoEmergencia(1000)) return;
// 3. Probar Canal M1 en sentido inverso
Serial.println("3. Probando Canal M1 (Sentido Inverso)...");
enviarComandoMotor(1, 180, false);
if (verificarParoEmergencia(2000)) return;
detenerMotores();
if (verificarParoEmergencia(1000)) return;
// 4. Probar Canal M2 en sentido inverso
Serial.println("4. Probando Canal M2 (Sentido Inverso)...");
enviarComandoMotor(2, 180, false);
if (verificarParoEmergencia(2000)) return;
detenerMotores();
}
/**
* Función para probar canales individuales del driver I2C
*/
void enviarComandoMotor(uint8_t canal, uint8_t velocidad, bool sentidoHorario) {
uint8_t m1_speed = (canal == 1) ? velocidad : 0;
uint8_t m2_speed = (canal == 2) ? velocidad : 0;
// Setear velocidades
Wire.beginTransmission(MOTOR_DRIVER_ADDR);
Wire.write(MOTOR_SPEED_SET);
Wire.write(m1_speed);
Wire.write(m2_speed);
Wire.endTransmission();
delay(2);
//