I made a simple circuit with a transistor to act as a relay for a 12v supply to an led strip, it gets turned on with an ultrasonic sensor that is connected to the Arduino uno , and when the digitalRead() > 0 than it toggles a pin HIGH which goes to the transistor. the sensor picks up things and the …

Can we see your schematic and code please? Maybe then we could help you better : )

The led strip appears to be powered on irrespective of the state of the relay that drives it ?

#include <NewPing.h> #define TRIG 2 #define ECHO 3 #define BUZZER 4 NewPing sonar (TRIG,ECHO,56); void setup() { // put your setup code here, to run once: Serial.begin(9600); pinMode(BUZZER,OUTPUT); delay(50); } void loop() { int P1 = sonar.ping_cm(); digitalWrite(BUZZER,LOW); // put yo…

Hi, Can you post a circuit diagram please? Where is the constant voltage? You do have the gnd of the Arduino connected to the gnd of the 12V LED supply? What model Arduino are you using? NewPing has a parameter #define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). …

the Arduino is connected to the 12v of the ground, I'm using an Arduino Uno, doing the thing that you said didn't help, and I will post a circuit diagram from Lt spice (unless there is another way to make an ez diagram that you recommend )

Hi, Think about it; if (P1 > 0){ Your target will always be further than zero away until it hits the ultrasonic device. What value does your serial print display? Can you please post a picture(s) of your project showing how you have the ultrasonic aligned with the object you wish to know the d…

[image] How to make a schematic you can post. Introductory Tutorials When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explai…

the project is used as a security alarm, when a door opens the ultrasonic sensor sees it and blinks the led (and will make a buzzer and send data to my phone eventually with databases) unless there is an object infront of it the serial prints "0" but when there is, it prints the distance that the ob…

Why don't you use a magnetic switch made for detecting open/closed doors? Also you can use the RCWL-0516 as a proximity sensor. It uses microwaves so maybe that can clear some wooden doors :thinking: .

Ghost Voltage? Back EMF? Transistor? Over Current?

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johnerrington January 25, 2022, 7:40am 9

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Ghost Voltage? Back EMF? Transistor? Over Current?

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