I'm new to programming and I'm trying to add an LDR sensor to my pre-existing traffic light system, basically, I want it so that when my sensor hits a certain threshold of darkness the time that it takes for the light to change decreases to 7 seconds for my red and green light, rather than 15. But I have absolutely no clue how to go about coding this? I've attached my TinkerCad arduino design and my code, I hope you can help me.
void setup()
{
pinMode(13, OUTPUT); // Red LED
pinMode(12, OUTPUT); // Yellow LED
pinMode(11, OUTPUT); // Green LED
}
void loop()
{
digitalWrite(13, HIGH); //Turns on the red light
delay(15000); // red light for 15 seconds
digitalWrite(13, LOW); // Turns off the red light
digitalWrite(12, HIGH); // Turns amber light on
delay(6000); // Keeps amber light on for 6 seconds
digitalWrite(12, LOW); // Turns amber light off
digitalWrite(11, HIGH); // Turns on green gight
delay(15000); // Keeps on for 15 seconds
digitalWrite(11, LOW); // Turns green light off
}
Also compare the way that you have wired the LDR with a known good example.
The LDR and the 10K resistor should be in a voltage divider arrangement, with the Analog pin in the middle.
Have You heard about analogRead? Can be used for the LDR.
Does this make any sense?
#define LDR_pin xx
#define darkValue yy
void setup()
{
pinMode(13, OUTPUT); // Red LED
pinMode(12, OUTPUT); // Yellow LED
pinMode(11, OUTPUT); // Green LED
pinMode(LDR_pin, INPUT); //Input for LDR
}
void loop()
{
if( analogRead(LDR_pin ) < darkvalue )
delay_time = 7000;
else
delay_time = 15000;
digitalWrite(13, HIGH); //Turns on the red light
delay(delayTime); // red light for 15 seconds
digitalWrite(13, LOW); // Turns off the red light
digitalWrite(12, HIGH); // Turns amber light on
delay(6000); // Keeps amber light on for 6 seconds
digitalWrite(12, LOW); // Turns amber light off
digitalWrite(11, HIGH); // Turns on green gight
delay(delayTime); // Keeps on for 15 seconds
digitalWrite(11, LOW); // Turns green light off
}
Railroader:
Have You heard about analogRead? Can be used for the LDR.
Does this make any sense?
#define LDR_pin xx
#define darkValue yy
void setup()
{
pinMode(13, OUTPUT); // Red LED
pinMode(12, OUTPUT); // Yellow LED
pinMode(11, OUTPUT); // Green LED
pinMode(LDR_pin, INPUT); Input for LDR
}
TheMemberFormerlyKnownAsAWOL:
According to your Fritzing thing, it's A0
Whenever I type the altered code these problems come up.
void setup()
{
pinMode(13, OUTPUT); // Red LED
pinMode(12, OUTPUT); // Yellow LED
pinMode(11, OUTPUT); // Green LED
pinMode(A0, INPUT); // Input for LDR
}
void loop()
{
if analogRead(A0) < 300 ;
delay_time = 7000;
else
delay_time = 15000;
digitalWrite(13, HIGH); //Turns on the red light
delay(delay_time); // red light for 15 seconds
digitalWrite(13, LOW); // Turns off the red light
digitalWrite(12, HIGH); // Turns amber light on
delay(6000); // Keeps amber light on for 6 seconds
digitalWrite(12, LOW); // Turns amber light off
digitalWrite(11, HIGH); // Turns on green gight
delay(delay_time); // Keeps on for 15 seconds
digitalWrite(11, LOW); // Turns green light off
}
In function 'void loop()':
13:7: error: expected '(' before 'analogRead'
14:6: error: 'delay_time' was not declared in this scope
14:6: note: suggested alternative: '_delay_ms'
16:3: error: 'else' without a previous 'if'
exit status 1
