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.
// Definisi frekuensi nada (dalam Hertz)
#define NOTE_C4 262
#define NOTE_D4 294
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_G4 392
#define NOTE_A4 440
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_D5 587 // <--- Nada D5 sekarang sudah ditambahkan
// Pin digital yang terhubung ke pin SIG buzzer
const int buzzerPin = 8;
// Melodi lagu "Balonku Ada Lima" (Bagian Awal)
// Nada: Ba-lon-ku a-da li-ma... ru-pa ru-pa war-na-nya
int melody[] = {
NOTE_G4, NOTE_G4, NOTE_C5, NOTE_G4, NOTE_E4, NOTE_G4, // Ba-lon-ku a-da li-ma
NOTE_C5, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_B4, NOTE_G4 // Ru-pa ru-pa war-na-nya
};
// Durasi masing-masing nada: 4 = ketukan seperempat (quarter note), 2 = ketukan setengah (lebih panjang)
int noteDurations[] = {
4, 4, 4, 4, 4, 2,
4, 4, 4, 4, 4, 2
};
void setup() {
// Iterasi melodi lagu (12 nada)
for (int thisNote = 0; thisNote < 12; thisNote++) {
// Menghitung durasi nada dalam milidetik
int noteDuration = 1000 / noteDurations[thisNote];
// Memainkan nada menggunakan fungsi tone()
tone(buzzerPin, melody[thisNote], noteDuration);
// Memberikan jeda antar nada agar suara tidak menyatu
int pauseBetweenNotes = noteDuration * 1.30;
delay(pauseBetweenNotes);
// Menghentikan suara pada pin setelah nada selesai
noTone(buzzerPin);
}
}
void loop() {
// Kosong agar lagu hanya berbunyi sekali saat Arduino dinyalakan/direset
}