Digital Input not going HIGH

Using Arduino General Electronics
#1

My First spin at using Fritzing… The external DC circuit is actually 24vdc… it wasn’t in the drop down so I just chose 12vdc. its a 5.1 zener and a 10K resistor…

I measure the lead going to the digital in and its reading a 4.4-4.5vdc… and from my understanding anything over about 3vdc should draw the digital in HIGH… but it stays low… Not sure what I am missing… I even used A0 to measure the voltage and A0 took a reading of ~4.5… Kinda stumped on what I am missing…

Not pulling digital high.png
Not pulling digital high.png867×714 37.1 KB

#2

Can't tell without the code

#3

I think you've got a software problem, or your Arduino is fried... Did you accidentally configure D7 as an output?

The easiest way to test an input pin is to connect it to +5V (high) and then to ground (low). (But, you don't want to try that unless you're sure the pin is configured as an input.)

I even used A0 to measure the voltage and A0 took a reading of ~4.5..

It's time for you to get a multimeter. :wink:

#4

I stripped the code down to nothing...

void setup() {
pinMode(7, INPUT);
Serial.begin(9600);
}

void loop(){
Serial.println(digitalRead(7));
delay(500);
}

Hardly to see anything to be wrong there...

#5

I did check with a multimeter..

Arduino is fine... if I use the onboard 5vdc it goes high....

Aparently I need glasses... Wrong input pin...

#6