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Help to arduino code

Former Member

Hi. (First I must say that I am from Denmark, so i hope that you understand my english.)

 

I hope that someone will help me. I have tried to make a code for my arduino uno. 

 

I want to have 3 LED's to increase light dependent on a signal from at tempeature sensor.

They should do it in different intervals, so that LED1 should increase light when the signal from the temperature sensor is between 165 and 200, and hold full light to everything above 200.

 

The LED2 should start at 200 and increase up to 225, and hold full light to everuthing above 225.

 

The LED3 should start at 225 and increase up to 240, and hold full light to everuthing above 240.

 

 

 

I have used PWM to control the LED's, but they all light all the time and when the temperature changes they increase and decrease in an uncontrolled way.

 

So my qustions are:

 

1. Why does the LED's light all the time and why do they increase and decrease uncontrolled?

 

As mentioned above, I would like to keep the LED's fully lighted if the value exceeds the limits in the 'if' statement.

 

So second question:

2. Can i in some way use 'constrain' to hold the LED's on when the temperature input signal is over the value that the light should increase on? IF not, what can I use?

 

I have attached the code.

Attachments:
LED_som_funktion_af_temp.ino.zip
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  • 0

    Without knowing your schematics, here are few things you might want to check:

    1. Is the analog 0 pin connected properly to your temp sensor ? If it's a DHT11, you might want to use a 10K ohm between pin 2 (data) to VCC to prevent fluctuation, adafruit has a good schematic for DHT11 as a starting point, note that they use pwm pin 2 in their code, so you want to modify the code to your connection.

    2. Why do you clip the constraint to 0, 200 and then test data up to 240? It looks like a bug, maybe you want to use val = constraint (165, 240) or something, what happen if value is somewhere between 0 and 165, there is no code to do anything for the LEDs

    3. your 500ms delay seems too fast, why so fast? I usually have a delay like 10sec and even that I find it too much work for the arduino.

    Good luck.

  • 0 in reply to anhtien

    anhtien: Thanks for your answer.

     

    1. Right now im using a pot meter instead of the temperature sensor, but i dont have a 10K ohm resistor in circuit. I am not sure if it will help me, because I am reading the signal that goes in on analog 0 with the 'serial monitor' and there dosnt seem to be any interruptions.

     

    2. I attahced the wrong code image  I have attahced the right one now.

     

    3. It dosnt have to be so fast, but i dont see why it should be a problem?

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  • 0 in reply to anhtien

    anhtien: Thanks for your answer.

     

    1. Right now im using a pot meter instead of the temperature sensor, but i dont have a 10K ohm resistor in circuit. I am not sure if it will help me, because I am reading the signal that goes in on analog 0 with the 'serial monitor' and there dosnt seem to be any interruptions.

     

    2. I attahced the wrong code image  I have attahced the right one now.

     

    3. It dosnt have to be so fast, but i dont see why it should be a problem?

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