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+ version with enum instead of function pointer.

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edited Aug 6, 2016 at 14:31

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Here is another version, that uses an enum instead of a function pointer to identify the gate. The constants and the setup() are the same as before, then:

void loop()
{
    // The gate we want to test.
    static enum { AND, OR, NAND } gate;

    // Select the gate through the serial port.
    switch (Serial.read()) {
        case 'a': gate = AND;  Serial.println("AND");  break;
        case 'o': gate = OR;   Serial.println("OR");   break;
        case 'n': gate = NAND; Serial.println("NAND"); break;
    }

    // Simulate the gate.
    bool a = !digitalRead(inputA);  // input is in negative logic
    bool b = !digitalRead(inputB);
    digitalWrite(outputA, a);
    digitalWrite(outputB, b);
    bool res = false;
    switch (gate) {
        case AND:  res = a && b;    break;
        case OR:   res = a || b;    break;
        case NAND: res = !(a && b); break;
    }
    digitalWrite(outputRes, res);
}

Here is another version, that uses an enum instead of a function pointer to identify the gate. The constants and the setup() are the same as before, then:

void loop()
{
    // The gate we want to test.
    static enum { AND, OR, NAND } gate;

    // Select the gate through the serial port.
    switch (Serial.read()) {
        case 'a': gate = AND;  Serial.println("AND");  break;
        case 'o': gate = OR;   Serial.println("OR");   break;
        case 'n': gate = NAND; Serial.println("NAND"); break;
    }

    // Simulate the gate.
    bool a = !digitalRead(inputA);  // input is in negative logic
    bool b = !digitalRead(inputB);
    digitalWrite(outputA, a);
    digitalWrite(outputB, b);
    bool res = false;
    switch (gate) {
        case AND:  res = a && b;    break;
        case OR:   res = a || b;    break;
        case NAND: res = !(a && b); break;
    }
    digitalWrite(outputRes, res);
}

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answered Aug 6, 2016 at 12:59

Edgar Bonet

45.2k
4
42
81

For simulating different gates with the same program, an option is to use the serial port to tell it what gate you want it to simulate. Here I am also using a function pointer (called gate) to represent the selected gate:

/* Wiring. */
const int inputA    = 2;
const int inputB    = 3;
const int outputA   = 11;
const int outputB   = 12;
const int outputRes = 4;

void setup()
{
    pinMode(inputA,    INPUT_PULLUP);
    pinMode(inputB,    INPUT_PULLUP);
    pinMode(outputA,   OUTPUT);
    pinMode(outputB,   OUTPUT);    
    pinMode(outputRes, OUTPUT);
    Serial.begin(9600);
    Serial.println(F("Type 'a'(for AND), 'o' (OR) or 'n' (NAND)."));
}

/* Available gates. */
bool AND(bool a, bool b)  { return a && b; }
bool OR(bool a, bool b)   { return a || b; }
bool NAND(bool a, bool b) { return !(a && b); }

/* The gate we want to test. */
bool (*gate)(bool a, bool b) = AND;

void loop()
{
    // Select the gate through the serial port.
    switch (Serial.read()) {
        case 'a': gate = AND;  Serial.println("AND");  break;
        case 'o': gate = OR;   Serial.println("OR");   break;
        case 'n': gate = NAND; Serial.println("NAND"); break;
    }

    // Simulate the gate.
    bool a = !digitalRead(inputA);  // input is in negative logic
    bool b = !digitalRead(inputB);
    digitalWrite(outputA, a);
    digitalWrite(outputB, b);
    digitalWrite(outputRes, gate(a, b));
}