OK so I built up a circuit on a perfboard. It has a button. I noticed that my Serial output was not showing the change/button press/pull to GND.

The perfboard has female headers for an Arduino Nano. Fearing a wiring or soldering mistake or oversight, I removed the Nano(clone, old bootloader) from my perfboard headers, and wrote this basic test:

//Button tester
#define buttonpin 12
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(buttonpin, INPUT_PULLUP);
  Serial.println("*****************************");

}

void loop() {
  // put your main code here, to run repeatedly:
  int buttonstate=digitalRead(buttonpin);
  delay(250);
  if(buttonstate=1){
    Serial.println(buttonstate);
  }
  else if(buttonstate=0){
    Serial.println("OTHER");
  }
}

I tested pins 4,5,6 and 12 by connecting a dupont female-to-female header to the pin in the code, and both GND pins, each in-turn. The Serial output continuously indicated that the pin was HIGH.

So now I'm thinking, I've fried my Nano clone.

So I go grab another one that I hadn't unwrapped yet.

Same story...any digital pin, either ground, either with our without the internal pullups, no change in state.

How do I test properly out-of-circuit? Is there something I'm missing?

I've continuity checked my perfboard as well, but I can't even plug the Nano back in until I can do a successful button press?

I'm honestly confused. I'd get it if I'd fried Nano1 and Nano2 worked, but there is obviously some piece of knowledge that I lack.

Please note that at no time was Nano2 ever plugged into my perfboard. I opened the static bag and plugged it right into usb, uploaded the test, yada yada yada.

Just for giggles, I used HIGH and LOW in the "IF" statements. I also tested the input pins as output with a simple on/delay/off/delay and they worked just fine.

Thoughts?