Solar timer project to charge an EV

Projects General Guidance
66

It looks like it works, but you had to use several state variables to handle all the possible cases, and the if structure ended up being quite complex. Any future changes would be difficult to manage. On the other hand, if you fully separate concerns — for example, by filtering the "bright" timings upstream, before the main logic — you can dramatically simplify the entire program. For example:

//==============================================================================
const int LDR_PIN     = 34;  // Analog output pin from LDR module
const int SWITCH_PIN  = 14;  // Manual override switch (active LOW)
const int RELAY_PIN   = 25;  // SSR control pin

const int THRESHOLD   = 1000;            // Lower analog value = brighter light
const unsigned long WAIT_TIME = 1000;    // Shortened for testing

unsigned long t0;
bool f_bright = 0;  // Filtered bright
//==============================================================================
void setup() {
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(SWITCH_PIN, INPUT_PULLUP); // Manual override
  digitalWrite(RELAY_PIN, LOW);
  t0 = millis();
}
//==============================================================================
void loop() {
  bool ovr = !digitalRead(SWITCH_PIN);
  bool bright = analogRead(LDR_PIN) < THRESHOLD;
  if (bright == f_bright) 
    t0 = millis();
  else if (millis()-t0 >= WAIT_TIME) {
    t0 = millis();
    f_bright = bright;
  }
  digitalWrite(RELAY_PIN, f_bright || ovr);
  delay(20);  // About 50 Hz polling
}
//==============================================================================