I am very new to the Arduino with very little of background and knowledge and kindly asking you for help...
I am building a simple light detector / measurement, using LDR which. I am sure that most of you know it as it is very popular in Google search.
On the original sketch, the light value are continuously and fastly updated to the serial monitor. I modify the sketch, so the light value is updated very fast, e.g. 50msec and when the light intensity is exceeding the limit, it will turn the LED on and hold the LED at least for 3 seconds, without affecting (or adding more delay) to the 50msec update rate. I am trying this sketch but it does not work: on previous version, it add 3second delay to the update rate and on this version, the LED is not turn on;
/* The circuit requires LDR and 10k fixed resistor
The resistor connects to +5V and LDR connects to GND
LDR and pin junction connected to A0
*/
int led = 13; //LED, digital pin 13
int senRead = 0; //Readings from sensor to analog pin 0
int limit = 100; //Light threshold
void setup()
{
pinMode(led, OUTPUT);
Serial.begin(115200); //Set serial monitor at baud rate of 115200
}
void loop()
{
int val = analogRead(senRead); //Values from the sensor
Serial.println(val); //Prints the values from the sensor in serial monitor
delay(50); //Update rate sent to serial monitor
}
void HoldLED (int val)
{
if (val < limit) //If the light falls below the threshold it should turns the LED on for 1.5sec
{
digitalWrite(led, HIGH); //LED ON
delay(1000);
digitalWrite(led, LOW); //Then turns the LED back off
delay(3000); //And prevent the LED turned on for at least 3seconds
}
else if (val > limit) //If the light level is higher then threshold the LED should remain off
{
digitalWrite(led, LOW); //LED OFF
}
}
Forgive me should I make any mistakes on this posting.
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Thank you very much for giving me some guide on using this forum. Next time should be better to me. Now I try to fix the code format.
/* The circuit requires LDR and 10k fixed resistor
* The resistor connects to +5V and LDR connects to GND
* LDR and pin junction connected to A0
*/
int led = 13; //LED, digital pin 13
int senRead = 0; //Readings from sensor to analog pin 0
int limit = 100; //Light threshold
void setup()
{
pinMode(led, OUTPUT);
Serial.begin(115200); //Set serial monitor at baud rate of 115200
}
void loop()
{
int val = analogRead(senRead); //Values from the sensor
Serial.println(val); //Prints the values from the sensor in serial monitor
delay(50); //Update rate sent to serial monitor
}
void HoldLED (int val)
{
if (val > limit) //If the light exceed the threshold it should turns the LED on for 1.5sec
{
digitalWrite(led, HIGH); //LED ON
delay(1500);
digitalWrite(led, LOW); //Then turns the LED back off
delay(3000); //And prevent the LED turned on for at least 3seconds
}
else if (val < limit) //If the light level is lower than threshold the LED should remain off
{
digitalWrite(led, LOW); //LED OFF
}
}
*Some correction is made on the code comments.
I hope this can help me. Thank you very much for your help and attention.
In the version that worked, did you have a call to the function HoldLED() in the main loop? As you have currently structured the program, this function is never called.
6v6gt:
In the version that worked, did you have a call to the function HoldLED() in the main loop? As you have currently structured the program, this function is never called.
You gave me an enlightenment. Almost understand. I'll try...
@Robin2, very interesting and thank you very much for your suggestion. As a very new to Arduino, I have to learn more on how to make delay using millis (). May be you could give me suggestion too
