I have a really simple code that is not behaving how I would expect it to.
Here's the code:
int i;
void setup() {
Serial.begin(9600);
pinMode(13, OUTPUT);
}
void loop() {
//digitalWrite(13, HIGH);
i = random(1,5);
Serial.println(i);
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
}
With this code the LED only blinks when Serial Monitor is on and stays on while Serial Monitor is off. Another problem I have is that if I comment out the current digitalWrite(LED_BUILTIN, HIGH) and replace it with the one I have commented out then the LED wont blink even if Serial Monitor is off.
I have Arduino Micro
If you want to blink a LED, you need to add an extra delay when the LED is going from OFF to ON.
Currently you have:
LED ON -> wait -> LED OFF -> (instantly) LED ON -> wait etc
So what you see is just the LED continuously ON, to make it work add another delay(1000) before digitalWrite(13, HIGH) for example:
int i;
void setup() {
Serial.begin(9600);
pinMode(13, OUTPUT);
}
void loop() {
//digitalWrite(13, HIGH);
i = random(1,5);
Serial.println(i);
delay(1000);
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
}
I tested it on my Arduino Nano and it worked fine.
Related
I cannot explain to myself why this code works properly in some cases and in some not. Here is the situation:
I am trying to switch a relay with the Arduino Nano. Therefore I took the "Blink" example as a guide. It should switch on for like 5 minutes and switch off for like 25 minutes. Here is the code:
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED_BUILTIN, OUTPUT);
pinMode(2, OUTPUT); // sets PIN 2 as switcher for the relay
}
// the loop function runs over and over again forever
void loop() {
int count = 0;
int run_pump = 300; // 5 Min run
int stop_pump = 1500; // 25 Min stop
digitalWrite(LED_BUILTIN, LOW); // turn the LED off (HIGH is the voltage level)
digitalWrite(2, HIGH); // turn the pump on
while(count < run_pump) {
count++;
delay(1000); // wait for a second
}
count = 0;
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on by making the voltage LOW
digitalWrite(2, LOW); // turn the pump off
while(count < stop_pump) {
count++;
delay(1000); // wait for a second
}
}
if I run this code on the Arduino it will just switch on the relay forever. BUT: If I set run_pump and stop_pump for like 10 sec. it will work properly! Is there an explanation why this does not work with the bigger counters? It's so confusing....
so this code here works absolutely fine, but why does the code above not?
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED_BUILTIN, OUTPUT);
pinMode(2, OUTPUT); // sets PIN 2 as switcher for the relay
}
// the loop function runs over and over again forever
void loop() {
int count = 0;
int run_pump = 5; // 5 sec run
int stop_pump = 10; // 10 sec stop
digitalWrite(LED_BUILTIN, LOW); // turn the LED off (HIGH is the voltage level)
digitalWrite(2, HIGH); // turn the pump on
while(count < run_pump) {
count++;
delay(1000); // wait for a second
}
count = 0;
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on by making the voltage LOW
digitalWrite(2, LOW); // turn the pump off
while(count < stop_pump) {
count++;
delay(1000); // wait for a second
}
}
Hope someone has a clue.... Thanks!
Tom
OK guys, I solved it. The problem was a cheap relay that was trying to communicate with the Arduino... Replacing it with a better one solved the whole problem. Thanks for the idea with the LED, this brought some stones to roll... :)
So it's a simple problem, I have several LEDs on a board where depending on their states it will trigger a command to fire a relay. Where I am stuck is figuring out how to get the Arduino to see a blinking LED, I have tried to bypass it all together but the code got larger than we wanted so it was scrapped and I am starting all over. Any ideas would be most helpful. Here is the basic code:
int Relay = 2;
int Led = 7;
int Ball = 8;
void setup()
{
Serial.begin(115200);
pinMode(Relay, OUTPUT);
pinMode(Led, INPUT);
pinMode(Ball, OUTPUT);
}
void loop()
{
digitalWrite (Relay, HIGH);
delay (500);
digitalWrite (Relay, LOW);
delay(300);
digitalRead(Led);
if(Led == HIGH)
{
digitalWrite(Ball, HIGH);
}
if(Led == LOW)
{
digitalWrite(Ball, LOW);
}
}
digitalRead(Led) throws away the value you are reading, and if (Led == LOW) is comparing a pin number with a voltage level, which is meaningless. You mean:
level = digitalRead(Led);
if (level == HIGH) { ...
Ok, so I have started my Project 2 on Arduino Uno. It involves 3 blinking leds. The original idea is that the green led will be lit until a switch is pressed which will make the other two leds blink consecutively. However, I have tried to make the green led keep blinking until I press the switch (instead of it just being lit passively prior to the pressing of the switch). So I made one small adjustment to the if statement, however this didn't work (the led blinked once and then continued being lit).
int switchState=0;
void setup() {
pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
pinMode(2, INPUT);
// put your setup code here, to run once:
}
void loop() {
switchState= digitalRead(2);
if (switchState==LOW) {
digitalWrite(3, HIGH);
delay(1000);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
}
else {
digitalWrite(3,LOW);
digitalWrite(4,LOW);
digitalWrite(5, HIGH);
delay(250);
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
delay(250);
}
// put your main code here, to run repeatedly:
}
The green LED is assigned to pd3 and the two other leds to pd4 and pd5.
So why, upon the verification of the condition, (whether the switch was pressed or not), does the led blink only once- shouldn't it continue blinking? However when I inserted another delay after the 2nd digitalWrite(3, LOW), it worked. Whats the explanation for this? I'm new to this so please make your explanation clear.
Case 1:
The user does not press switch the switch for at least > delay(1000); to run again.
In this section:
switchState= digitalRead(2);
if (switchState==LOW) // <---- User is not pressing switch so we
{ // enter the if.
digitalWrite(3, HIGH);
delay(1000);
digitalWrite(3, LOW);
// Adding delay here makes it blink.
digitalWrite(4, LOW);
digitalWrite(5, LOW);
}
Once you have done the digitalWrite(3, LOW); , it is in micro/miliseconds before the loop is repeated and you enter the if again. The LED actually did blink, but it is so fast you can't see it. The LED would stay on as long as the user didn't press the the button.
Case 2:
User pressed button and after running through the if statement at least once. The LED is left OFF as it enters the else.
else
{
digitalWrite(3,LOW);
digitalWrite(4,LOW);
digitalWrite(5, HIGH);
delay(250);
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
delay(250);
}
The LED is set again to LOW and then remains OFF.
Does that help?
I am trying to write a simple control program for an Arduino Uno for an experiment I'm running at work. Quite simply it just needs to read if an input pin is high, if it is wait 10 milliseconds to turn an output pin high, hold for 10 milliseconds then go low, else the output pin is low.
My problem is that when I run this it ignores the initial delay altogether, and the output pin stays high for several seconds before going low. (using delayMicroseconds)
void setup()
{
pinMode(8, INPUT);
pinMode(13, OUTPUT);
}
void loop()
{
if (digitalRead(8) == HIGH)
{
delayMicroseconds(10000); //wait 10 milliseconds
digitalWrite(13, HIGH); // Pump on
delayMicroseconds(10000); // holds for pulse width of 10 millisecond
digitalWrite(13, LOW); // Pump off
}
else
{
}
}
I've tried setting up something simpler for debugging using the delay function to wait for a second, then turn output pin high, wait for a seconds, then turn output pin low. I did this so I could visually debug using the arduino's built in LED. the result is that it actually continues to run the loop 3 times after the input pin goes low. (using delay)
void setup()
{
pinMode(8, INPUT);
pinMode(13, OUTPUT);
}
void loop()
{
if (digitalRead(8) == HIGH)
{
delay(1000); //wait 1 second
digitalWrite(13, HIGH); // Pump on
delay(1000); // hold for 1 second
digitalWrite(13, LOW); // Pump off
}
else
{
}
}
I can't seem to figure out why it's doing this. I've looked all over and can't seem to find information about why this would happen. I might be missing something really simple, I am not an experienced coder, I just write what I need to run experiments. I've tried reading and writing to the pin register directly using c code, and switching from an if statement to a while loop, none of them fixed the problem. Any insight is greatly appreciated.
You should look at the internal pull-up resistors on the Arduino. You can debounce the signal from your button entirely with software:
void setup() {
pinMode(2, INPUT_PULLUP);
}
void loop() {
if (digitalRead(2) == LOW) // NOTE THAT PULLUPS REVERSE YOUR LOGIC
{
delay(1000); //wait 1 second
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
}
}
My problem is that I am making an alarm that goes off when the temperature is greater than a preset amount. however the Arduino is going past the if statement and not stopping at the gate.
I have tried looking up different syntax however it keeps going through the if statement like it is not there while it still serial prints.
//naming the led's left to right defining the pin and the constant int
//coded by luke
// the breadboard has 6 leds lined up by order 1,2,3,4,5,6 on the corresponding pins
//6.28.2014
// second program written from scratch
// !buzzer pin 8!
// integers
const int led1=(1);
const int led2=(2);
const int led3=(3);
const int led4=(4);
const int led5=(5);
const int led6=(6);
const int buzzer=(8);
const int temp=(0);
int maxtemp=(80);
// place the buzzer at pin 8 for sound
void setup()
{
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
pinMode(led5, OUTPUT);
pinMode(led6, OUTPUT);
pinMode(temp, INPUT);
Serial.begin(9600);
}
void loop()
{
delay (1000);
analogRead(temp);
delay (100);
Serial.print(analogRead(temp)/2.05);
delay (10);
if(analogRead(temp/2.05) > maxtemp)
{
tone (buzzer, 440);
delay (100); // wait to turn on the second
digitalWrite(led2, HIGH);
delay (100);
digitalWrite(led1, LOW);
delay (100);
digitalWrite (led3, HIGH);
delay (100);
digitalWrite (led2, LOW);
delay (100);
tone (buzzer, 450);
digitalWrite (led4, HIGH);
delay (100);
digitalWrite (led3, LOW);
delay (100);
digitalWrite (led5, HIGH);
delay (100);
digitalWrite (led4, LOW);
delay (100);
digitalWrite (led6, HIGH);
delay (100);
digitalWrite (led5, LOW);
delay (100);
digitalWrite (led6, LOW);
}
}
// put your main code here, to run repeatedly:
What you're printing to serial is not the same as what you're comparing to maxtemp in the if statement:
Serial.print(analogRead(temp)/2.05);
if(analogRead(temp/2.05) > maxtemp)
The former has /2.05 outside the analogRead call, the latter has it inside. Assuming the former is reporting what you expect to see, changing the if statement to:
if((analogRead(temp) / 2.05) > maxtemp)
Should fix the problem.