I'm writing a program with three different cases. Case one an LED is off, in another it is on and in the last case the brightness is controlled by a potentiometer. Each case works as I press the button. The issue I am having is with the third case. The potentiometer is read only once and the LED is set accordingly. I would like the LED to be adjusted continuously until the button is pushed again and the case is switched to off. I used the Serial.print to see the valves read from the potentiometer. I verified its only read once on each cycle through the different cases. I also changed from a SWITCH/CASE to If statements and it only reads the potentiometer once.

    static enum { OFF, ON, POT } state;
    unsigned long now = millis();

    // Switch state on button press.
    if (button_press()) switch (state) {
    case OFF:
        analogWrite(LED_PIN, 255);
        state = ON;
        break;
    case ON:
        analogWrite(LED_PIN, 0);
        state = POT;
        break;
    case POT:
        val = (analogRead(pot) / 4);
        analogWrite(LED_PIN, val);
        Serial.println(val);
        state = OFF;
        break;
    }