Trying to control relay with Arduino Yun....(PLEASE HELP ME!)

Hardware Arduino Yún
1

Hi guys :slight_smile:
As I mentioned in title, I'm trying to control relay with my arduino yun(and my own webpage.)
I'm just getting everything right but my relay won't work right. :o :o
I wrote the code bellow which I'm having trouble with.

HttpClient client_2;
        client_2.get(Help);
        int c = client_2.read();
        int k = c-48;
        if (client_2.available()){
          
          Serial.println(c);          
          Serial.println(k);
          if(k==1){
            Serial.println("ON");
            digitalWrite(Relay,HIGH);
          }
          else{
            Serial.println("OFF");
            digitalWrite(Relay,HIGH);
            
          }

I first wrote the code with "char c" instead of "int c" but it did not work.
So I changed them into "int" type. In the Serial moniter, I'm getting
49
1
ON
which means the code is working great! However, my relay won't turn on....
It would be great to know the problem. Please help me!

2

Thats only partial code.

If you want anyone to take a better look at it then please post the WHOLE sketch along with a schematic (even hand drawn will do).

Some relays take a little more current than some boards can supply and may need an external supply but with a common ground to the Arduino.

I have a few relays and relay modules a couple of which will not work on the MKR and 101 series boards as the output is just not quite enough yet a very similar relay modules work great on everything else.

3

I'll second bob: post the full sketch and schematic.

It could be a wiring error, a design flaw in the way it's hooked up, or a problem in the sketch. Bob hit on a few potential electrical issues, and here's a potential problem in the sketch: did you perform a pinmode() call to set relay pin to be an output?