I am testing out the HC-SR501 PIR sensor on arduino. I tried a simple code tutorial online
int buzz = 13;
int pir = 2;
int value = 0;
int pirState = LOW;
void setup() {
pinMode(buzz, OUTPUT);
pinMode(pir, INPUT);
Serial.begin(9600);
}
void loop() {
delay(5000);
value = digitalRead(pir);
if (value == HIGH) {
digitalWrite(buzz, HIGH);
if (pirState == LOW) {
Serial.println("Motion Detected!");
pirState = HIGH;
}
} else {
digitalWrite(buzz, LOW);
if (pirState == HIGH){
Serial.println("Motion Ended!");
pirState = LOW;
}
}
}
This works, however, I'm trying to initialize it to a LOW output. When I first turn on the board, it initially gives me a high output, and so the buzzer activates instantly, even though I placed it away from myself. The serial prints out Motion Detected. I tried adding a delay, however it still gives out a HIGH output afterwards. Anyone knows how to solve this?
Thank you!
The pinMode sets the pin as an output, but the default state is LOW, so there should be no problem with it.
However, pin 13 is wired to onboard LED. And the onboard LED is also used by bootloader to signal its activity after the reset. You should check other pins but 13.
Related
I an getting a constant HIGH from 'inputPintwo' on the serial monitor. When 'inputPin' goes HIGH the relay is triggered and works properly because 'inputPintwo' is also HIGH (all the time).
I have a Very similar setup to: 2 PIR motion sensors +Arduino
I am not using pin 0 or 1 like the above answered question. I have replaced the sensor with a different one, in case it was bad hardware. I also unplugged the sensor and it still reads HIGH. The jumper is on retriggering on both sensors.
int ledPin = 13;
int inputPin = 2;
int inputPintwo = 4;
int pirState = LOW;
int val = 0;
int valtwo = 0;
#define RELAY1 7
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(inputPin, INPUT);
pinMode(inputPintwo, INPUT);
pinMode(RELAY1, OUTPUT);
Serial.begin(9600);
}
void loop(){
val = digitalRead(inputPin);
valtwo = digitalRead(inputPintwo);
if (val == HIGH && valtwo == HIGH) {
digitalWrite(ledPin, HIGH);
if (pirState == LOW) {
Serial.println("Motion detected!");
pirState = HIGH;
Serial.println("Light ON");
digitalWrite(RELAY1,1);
delay(500);
digitalWrite(RELAY1,0);
delay(500);
digitalWrite(RELAY1,1);
delay(500);
digitalWrite(RELAY1,0);
delay(500);
digitalWrite(RELAY1,1);
}
}
else {
digitalWrite(ledPin, LOW);
if (pirState == HIGH){
Serial.println("Motion ended!");
digitalWrite(RELAY1,0);
pirState = LOW;
Serial.println("Light OFF");
}
}
}
I expect both sensors to go HIGH only when motion is detected, which will cause the relay to go on and off several times, then stay on until the timer runs out on the sensors.
To identify the problem I recommend you to start with checking the hardware. You will need voltmeter/multimeter.
Double check if you are interfacing the sensor properly (check datasheet). Didn't you forget to connect e.g. the pull-down resistors?
Check power supply voltage on sensors – is the voltage within
manufacturer specifications?
Check breadboard connections if you are using one.
Check sensor output behaviour (voltage), if there is or is not a movement. Is the voltage constant or not? Constant voltage means that PIR sensor is NOT working properly. Before performing of this test disconnect output from Arduino input.
If everything seems OK or you do not have voltmeter, try to disconnect the PIR sensor and connect a wire between Arduino pin 4 and ground. Does digitalRead(inputPintwo) return LOW? If yes, you know that reading of the pin state works fine.
Below please see some recommendations related to your code:
use #define directive or static const int variable type to define Arduino pins as you do it with relay output pin RELAY1.
Example:
#define LED_PIN 13
#define INPUT_PIN 2
#define INPUT_PINTWO 4
or
static const int ledPin = 13;
static const int inputPin = 2;
static const int inputPintwo = 4;
In your case, where you are only interested in digital value (LOW/HIGH), use built pull-up resistor on the input pins. Thus the log. voltage level on the floating input pin is defined (HIGH). If you do not use pull-up resistors, voltage can be either log. 0 (LOW) or log. 1 (HIGH), what can lead to strange program/state machine behaviour
To activate pull-up resistors in the input pins, use
pinMode(inputPin, INPUT_PULLUP);
pinMode(inputPintwo, INPUT_PULLUP);
I'm working with simple Arduino where I'm trying to turn on a LED light by using serial print and turning off the LED Light when I click the button or use the switch on the board, when the pin is in the ground.
At the moment, I can turn on the led light by serial, however when I click the button the LED light will switch off but then never switch on, and that's happening because the state is being stuck at low all the time and never switching back to high.
Here's the code:
// constants won't change. They're used here to
// set pin numbers:
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 3; // the number of the LED pin
int state = 0;
// variables will change:
int buttonState = 0; // variable for reading the pushbutton status
void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT);
Serial.begin(9600);
}
void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);
if (Serial.available())
{
state = Serial.parseInt();
if (state == 1)
{
digitalWrite(ledPin, HIGH);
Serial.println("ON");
}
}
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
if (buttonState == LOW) {
state = 0;
// turn LED OFF:
Serial.println("off");
digitalWrite(ledPin, LOW);
}
// IMP : This Never runs. the state is always off therefore when i send to serial " 1" the led just blinks
else {
Serial.println("off");
}
}
The state is always off therefore when I send to serial " 1" the LED just blinks
I think you are reading state from PIN using wrong function.
if (Serial.available())
{
state = Serial.parseInt();
Why not use https://www.arduino.cc/reference/en/language/functions/digital-io/digitalread/ ?
Are you sure this condition is evaluated to true? if (Serial.available()) ?
You are making the logic too much complicate. Just check the serial if it is available and have the desire value turn led on else check the button and if it pressed turn the led off. On other conditions DO NOTHING. That is all you need.
// set pin numbers:
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 3; // the number of the LED pin
int state = 0;
// variables will change:
int buttonState = 0; // variable for reading the pushbutton status
void setup()
{
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT);
Serial.begin(9600);
}
void loop()
{
if (Serial.available())
{
state = Serial.parseInt();
if (state == 1)
{
digitalWrite(ledPin, HIGH);
Serial.println("ON");
}
}
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
else if (digitalRead(buttonPin) == HIGH)
{
// turn LED OFF:
Serial.println("off");
digitalWrite(ledPin, LOW);
}
}
I have been using my Arduino to control motor polarity with a Cytron MD-10 motor driver shield, and I had it working.
Then when I came back to work it seemed as though the digital read pins were not differentiating between high and low voltage and one of the lights was powered on continuously.
The outputs function as set up with a continuous supply of measured 4.84 volts and then the switch is closed the voltage drops to 0 and the corresponding loop should be entered. Is my board fried?
Anything I should try?
const int outSwitch = 13;
const int inSwitch = 12;
const int pinPWM = 3;
const int pinDir = 2;
int lightOne = 11;
int lightTwo = 10;
static int Dir = 1;
static int cycleCounter = 0;
void setup() {
// Set Pin Out/Inputs:
pinMode(pinPWM, OUTPUT);
pinMode(pinDir, OUTPUT);
pinMode(outSwitch, INPUT);
pinMode(inSwitch, INPUT);
pinMode(lightOne, OUTPUT);
pinMode(lightTwo, OUTPUT);
analogWrite(pinPWM, LOW);
}
void loop() {
// Both read a low input value from the switch and then makes
// direction the opposite causing it to travel backwards:
if(digitalRead(inSwitch == LOW)){
analogWrite(pinPWM, HIGH);
digitalWrite(pinDir, Dir);
digitalWrite(lightOne, LOW);
digitalWrite(lightTwo, HIGH);
}
else if(digitalRead(outSwitch == LOW)){
analogWrite(pinPWM, HIGH);
digitalWrite(pinDir, -Dir);
digitalWrite(lightOne, LOW);
digitalWrite(lightTwo, HIGH);
}
}
Sma correctly identified the problem as a misplacement of the parentheses:
if (digitalRead(inSwitch == LOW)) // OOPS!
This compares inSwitch to LOW, which probably returns false. Since digitalRead expects an int, that false is converted to 0. So you do a read of pin 0. I don't think there is a pin 0, so you probably get an error. That return value is then implicitly compared to 0 in order to determine which branch of the if-statement to take.
The correct statement would look like this:
if (digitalRead(inSwitch) == LOW)
(Community Wiki because I'm just trying to provide a more detailed answer. I'm not trying to get rep for someone else's observation.)
What does analogWrite(pinPWM, HIGH); even mean? Missing a value (0-255), HIGH is not a valid value.
I'm trying to make a microcontroller with an arduino. I am supplying with +5volt from the arduino, sending it to an NC button (so i can manually decide when to output a certain timed pulse). After the button it goes to a pin that I have set as an inPin (pin8). Then I want the program to make pin 7 HIGH(with a delay), and then it goes to a transistor.
This is the code I tried making (I know almost nothing about coding):
int ledPin = 7;
int inPin = 8;
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(inPin, INPUT);
}
void loop()
{
if (inPin=HIGH) {
digitalWrite(ledPin, HIGH);
}
delay (500);
digitalWrite(ledPin, LOW);
}
For some reason the outPin is HIGH all the time. I remembered to hook up a resistor to GND so the digital pin would stay LOW when supposed to be LOW.
Thanks in advance!
if(inPin=HIGH) is a mistake, first of all use "==" instead of "=". ALso you need to READ input pin state: int invalue = digitalRead(inPin);
Also, all pins by default coonfigured as inputs, so you don't need use pinMode(inPin, INPUT);
After those changes your code will look like:
int ledPin = 7;
int inPin = 8;
void setup() {
pinMode(ledPin, OUTPUT);
}
void loop()
{
if (digitalRead(inPin)==HIGH) digitalWrite(ledPin, HIGH);
delay (500);
digitalWrite(ledPin, LOW);
}
I am just creating a simple basic program, but I can't figure out what's going wrong.
I have set three pins as output and three pins as input. When those three pins digitalRead == HIGH they will set an LED to HIGH, but instead my LED is always staying high.
Here is my Arduino code:
int LED_Low = 4; // Red LED
int LED_Avg = 3; // Yellow LED
int LED_High = 2; // Green Led
int WaterLow = 7;
int WaterAvg = 8;
int WaterHigh = 9;
void setup() {
// Put your setup code here, to run once:
pinMode(LED_Low, OUTPUT);
pinMode(LED_Avg, OUTPUT);
pinMode(LED_High, OUTPUT);
pinMode(WaterLow, INPUT);
pinMode(WaterAvg, INPUT);
pinMode(WaterHigh, INPUT);
}
void check(){
if(digitalRead(WaterLow) == HIGH){ // If Water level is low
digitalWrite(ledLow, HIGH); // Turn on red LED indication water level is low
}
else{
digitalWrite(ledLow, LOW);
}
if(digitalRead(WaterAvg) == HIGH){ // If water level is medium
digitalWrite(ledAvg, HIGH); // Turn on yellow LED indicating water level is average
}
else{
digitalWrite(ledAvg, LOW);
}
if(digitalRead(WaterHigh) == HIGH){ //
digitalWrite(ledHigh, HIGH); //
}
else{
digitalWrite(ledHigh, LOW);
}
}
void loop() {
// Put your main code here, to run repeatedly:
check();
}
In the above image I have connected led on pin 2, 3, and 4 with 1.5 kilohm resistor and three wires in pin 7, 8, and 9 which will receive input from the 5 volt pin and turn on the LED. Accordingly, the 5 volt pin is connected to the positive terminal on the power bus and with 9.1 *2 resistors in series and then this wire connect with pin 2, 3, and 4.
I found the issue. My code was OK. It was my circuit.
The pins I declared to receive input were not connected to ground.
You can make that with the help of two cases
Define the delay
if (digitalRead(WaterLow) == HIGH) // If Water level is low
{
digitalWrite(ledLow, HIGH); // Turn red LED indication water level is low
delay(2000);
}
else
{
digitalWrite(ledLow, LOW);
}
Make a condition like this
int stateled = LOW;
int previous = LOW;
long time = 0;
long debounce = 200;
void loop()
{
stateButton = digitalRead(WaterLow);
if (stateButton == HIGH && previous == LOW && millis() - time > debounce)
{
if(stateLED == HIGH)
{
stateLED = LOW;
}
else
{
stateLED = HIGH;
}
time = millis();
}
digitalWrite(ledlow, stateLED);
previous == stateButton;
}