Need 10 minutes from an Arduino Expert

can somebody just skype with me for five minutes, im sure its a simple issue, i just don't know much

The people trying to help here are all over the world.. literally so many different time zones, we get to respond when we have a moment from our busy lives and as a principal we dont skype etc, this would lead us to not getting other things done, if you, then the next etc. and it would never be just 5mins, we have way too much experiance with these things to assume only 5mins would be enough

+ as already stated, this is a community and we help the community and expect the responses to be shared with the community. putting things here helps people see a history of the issue, how it was resolved etc. + by getting you to walk through it, you will also learn much more.

I am sorry if we seem to be a pain by making you do it this way but the other 200,000+++ folks are quite happy to conform, please understand, nothing personal, just the right way to move forward

*Bump* this is also open to anybody else who wasn't mentioned above, i really need help with this.

Hi Gabriel,

I suspect that your relay is drawing more current than the number 2 output of the Arduino can supply. The Arduino should drive a transistor, probably a small gate level MOSFET, and the transistor should connect the relay to the main power. Be certain to put a reverse biased diode across the relay coil to protect the circuit and a 470 uF capacitor from 5 Volt plus to ground will also improve the operation as it will stabilize the 5 volt supply.

Here is a schematic:

John

thanks, i think somebody also recommended that here, http://linustechtips.com/main/topic/449615-arduino-relay-help/ , is the sketch he supplied going to work

Hi Gabriel,

Yes this is the same idea. I suggested the MOSFET as I find they are easier to use than the BJTs. The Capacitor is just an extra precaution but the diode is pretty important to protect the transistor or MOSFET. Give it a try and get back to us with the results.

John

Hi Gabriel,

I subscribe the hypothesysof jw0752 But let me know a couple of details:

1. Are you powering the relay with 3.3 V or 5V from Arduino ?
2. Check the relay data sheet what is the drawing power
3. Are you using the relay also to power the led when it switches?

If 3. is true, I suggest that as should be done in the normal use, the Relay is just to use a low power (Arduino 5V) to switch the coil then the other side will use an external power to manage the device. If you leave the circuit as-it it is also possible it works with a LED but it is formerly wrong as the Relay is not used to power anything else (e.g. a motor or a more power device, like a 12V fan).

Take a look to the following schematics. This is the correct use of the Relay (it is a 5V powered relay so it will work fine with the Arduino power out) and is used to switch an external power supply. The relay area is highlighted in the red rectangle.

Enrico

im still really new to electronics so could you explain what the mosfet/transistor does, and link me to one cuz there are a lot of different models

I suggest before adding more complexity to the circuit, to try to see if the relays switches when is does not power nothing. Better if you show us the relay datasheet as for as an example. In the scheme shown above I have used a 5$ relay supporting up to 36V external powers.

Enrico

1, 5v

2, idk what that means

3, i think im using the relay to power the led, im still not 100% how relays work, but when the switch is connected in the relay, power goes through it to the led

yeah no it still goes on and off when its powering nothing

Trying to check your program again. The LED is replaced by the relay pin, correct ?

int analogValue;          // This is where we'll store our audio to digital value.  More sound = higher number
#define LED 2             // Set up the LED indicator
boolean toggle = false;   // setup a boolean function called toggle which will help us to choose which mode we're in
int numberOfClaps = 0;


void setup()
{

toggle = false; // *** Just to be sure
  pinMode(LED,OUTPUT);    // Pin#2 should be conencted to an LED through a 300-600 ohm resistor    
  Serial.begin(9600);     // This is optional - It just helps you to calibrate sensitivity after the fact
}


void loop()
{

      digitalWrite(LED,LOW);        // Turn the LED off - RELAY ?
        delay(2000);
      digitalWrite(LED,HIGH);       // Turn the LED on
        delay(2000);
}

Try this first. If the relay switches every two seconds, it's a problem of logic so should check the issue in your code else it is a problem of circuit or powering. What is the power drain by the relay?

Enrico

Trying to check your program again. The LED is replaced by the relay pin, correct ?

int analogValue;          // This is where we'll store our audio to digital value.  More sound = higher number
#define LED 2             // Set up the LED indicator
boolean toggle = false;   // setup a boolean function called toggle which will help us to choose which mode we're in
int numberOfClaps = 0;


void setup()
{

toggle = false; // *** Just to be sure
  pinMode(LED,OUTPUT);    // Pin#2 should be conencted to an LED through a 300-600 ohm resistor    
  Serial.begin(9600);     // This is optional - It just helps you to calibrate sensitivity after the fact
}


void loop()
{

      digitalWrite(LED,LOW);        // Turn the LED off - RELAY ?
        delay(2000);
      digitalWrite(LED,HIGH);       // Turn the LED on
        delay(2000);
}

Try this first. If the relay switches every two seconds, it's a problem of logic so should check the issue in your code else it is a problem of circuit or powering. What is the power drain by the relay?

Enrico