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.
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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.




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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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tes program
An interactive Arduino Nano circuit simulation you can run free in your browser on Velxio, by aripaintco.
#include <Wire.h>
#include <EEPROM.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
// =====================================================
// ARISTUDIO - LED STUDIO CONTROLLER
// Arduino Nano + OLED 128x64 + Rotary Encoder
//
// OPERASI:
// - STANDBY: putar rotary langsung mengatur BRIGHTNESS
// - Klik 1x: masuk COLOR TEMP
// - COLOR TEMP: putar rotary memilih Kelvin
// - Klik 1x: SET warna + kembali STANDBY
// - Hold 1 detik: ON/OFF SEMUA SISTEM dari mode apa pun
// OFF = LED putih mati + relay RGB mati
// ON = mode terakhir (putih / RGB) menyala kembali
// - MODE RGB AKTIF:
// Klik 1x = tampil layar STANDBY (klik lagi = kembali ke RGB MODE)
// (COLOR TEMP tidak dipakai saat mode RGB)
// - MODE RGB OFF: klik 1x = COLOR TEMP seperti biasa
// - Brightness: 0-100%
// - Color Temp: 3000-6500K
// - PWM 20 kHz
// - Anti-flicker
// - Soft Start
// - EEPROM
// - Buzzer: PUTAR / KLIK / ON-OFF
// - Buzzer D7
// - MENU TERSEMBUNYI: klik rotary 3x cepat dari STANDBY untuk setting suara
// =====================================================
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define OLED_ADDRESS 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
// =====================================================
// PIN ARDUINO NANO
// =====================================================
#define ENCODER_CLK 2
#define ENCODER_DT 3
#define ENCODER_SW 4
#define BUZZER_PIN 7
// Polaritas relay diatur di sini.
// Modul relay aktif-LOW: tukar nilainya (ON = LOW, OFF = HIGH).
#define RGB_RELAY_PIN A0
#define RGB_RELAY_ON HIGH
#define RGB_RELAY_OFF LOW
#define LED_WARM 9
#define LED_COOL 10
// =====================================================
// PWM 20 kHz
// Arduino Nano ATmega328P
// Timer1 Phase Correct PWM, TOP = 400
// =====================================================
#define PWM_TOP 400
// =====================================================
// MODE UI
// =====================================================
#define MODE_STANDBY 0
#define MODE_COLOR_TEMP 1
#define MODE_SOUND_MENU 2
byte uiMode = MODE_STANDBY;
// Pilihan menu tersembunyi: 0 = Buzzer, 1 = RGB Relay
byte hiddenMenuItem = 0;
// Pilihan mode RGB (tersimpan di EEPROM).
// Relay fisik hanya menyala jika rgbRelayOn && lampOn.
bool rgbRelayOn = false;
// Tampilan layar saat mode RGB aktif:
// false = layar "RGB MODE"
// true = layar "STANDBY" (muncul saat encoder diklik)
// Otomatis kembali false setiap mode RGB diubah.
bool rgbStandbyView = false;
// =====================================================
// SETTING
// =====================================================
int brightness = 5;
int colorTemp = 4500;
bool lampOn = true;
bool buzzerEnabled = true;
// Nilai Kelvin sementara saat memilih warna.
int selectedColorTemp = 4500;
// =====================================================
// EEPROM
// RGB DIHAPUS SEPENUHNYA
// =====================================================