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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.
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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.

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An interactive Arduino Mega circuit simulation you can run free in your browser on Velxio, by albertoarangurenp.
/*
===================================================================
BANCO DE PRUEBAS ECU - ARDUINO MEGA (ECU SIMULADA - ETAPA 2)
Entradas de Rotación: CKP (Pin 2), CMP1 (Pin 3), CMP2 (Pin 4)
===================================================================
*/
// Entradas de Alimentación desde el Banco
const int PIN_LINEA_30 = A0;
const int PIN_LINEA_15 = A1;
// Salidas de Alimentación de Sensores
const int PIN_VREF_OUT = 7;
const int PIN_MASA_SEN_OUT = 6;
// Entradas de Sensores de Rotación (Sincronización con Banco)
const int PIN_CKP_IN = 2; // Interrupt 0
const int PIN_CMP1_IN = 3; // Interrupt 1
const int PIN_CMP2_IN = 4; // Entrada Digital CMP2
// Salidas hacia Relés
const int PIN_RELE_PRINCIPAL = 30; // Activado por +15
const int PIN_RELE_BOMBA = 31; // Activado por movimiento CKP
// Salidas hacia Actuadores (Inyectores y Bobinas)
const int injPins[] = {8, 9, 10, 11}; // Inyectores Cil 1, 2, 3, 4
const int ignPins[] = {12, 13, 14, 15}; // Bobinas Cil 1, 2, 3, 4
const int ordenEncendido[] = {0, 2, 3, 1}; // Secuencia de disparo 1-3-4-2
// Variables de Estado Interno
bool ecuOperativa = false;
bool ultimoEstado15 = false;
volatile unsigned long ultimoPulsoCKP = 0;
volatile int conteoDientes = 0;
volatile int pasoSecuencia = 0;
volatile int cilindroActivo = -1;
volatile int pulsoDientesRestantes = 0;
bool motorGirando = false;
void setup() {
Serial.begin(115200);
// Configuración de Alimentación
pinMode(PIN_LINEA_30, INPUT);
pinMode(PIN_LINEA_15, INPUT);
// Configuración de Alimentación de Sensores
pinMode(PIN_VREF_OUT, OUTPUT);
pinMode(PIN_MASA_SEN_OUT, OUTPUT);
digitalWrite(PIN_VREF_OUT, LOW);
digitalWrite(PIN_MASA_SEN_OUT, HIGH);
// Configuración de Entradas CKP / CMP
pinMode(PIN_CKP_IN, INPUT_PULLUP);
pinMode(PIN_CMP1_IN, INPUT_PULLUP);
pinMode(PIN_CMP2_IN, INPUT_PULLUP);
// Configuración de Relés
pinMode(PIN_RELE_PRINCIPAL, OUTPUT);
pinMode(PIN_RELE_BOMBA, OUTPUT);
digitalWrite(PIN_RELE_PRINCIPAL, LOW);
digitalWrite(PIN_RELE_BOMBA, LOW);
// Configuración de Salidas de Potencia
for (int i = 0; i < 4; i++) {
pinMode(injPins[i], OUTPUT);
pinMode(ignPins[i], OUTPUT);
digitalWrite(injPins[i], LOW);
digitalWrite(ignPins[i], LOW);
}
// Interrupción en flanco de subida para la señal CKP (Pin 2)
attachInterrupt(digitalPinToInterrupt(PIN_CKP_IN), isrProcesarCKP, RISING);
Serial.println(F("=================================================="));
Serial.println(F(" ECU SIMULADA (MEGA) - CMP2 ASIGNADO AL PIN 4 "));
Serial.println(F("=================================================="));
}
void loop() {
float v30 = analogRead(PIN_LINEA_30) * 5.0 / 1023.0;
float v15 = analogRead(PIN_LINEA_15) * 5.0 / 1023.0;
bool switch15Activo = (v15 >= 2.5);
bool bateriaPresente = (v30 >= 2.5);
// Lógica de Ignición (+15)
if (switch15Activo != ultimoEstado15) {
ultimoEstado15 = switch15Activo;
if (bateriaPresente && switch15Activo)