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

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

thank you all for your elaborate suggestions but i just changed it from 5v to 3.3v and it works fine.  I don't know why, but i care, why does that make any difference at all?

Well happy to read this. There are two possible options in my view. The first is that the relay - for some unknown reasons - works at a lower power to the behaviour is unpredictable. The second is that you put the wrong power. Is suggest this just because I am not there, can you make a close-up shoot where the relay is connected to the power? If you have a tester check the real power that reach the relay.

Please mark as useful or correct answer the answers / suggestions of this question thread you consider correct or if none mark the question s "assume answered" so all the other users that search something can find this question useful.

Thank you. Enrico

There are several options to try.

1. See if you can use the Blink program in the Examples to simply toggle the relay on and off. (you'll need to change the pin to something other than pin 13)

This will prove that the Arduino can indeed power it.

2. What happens when you power the relay on and off, simply by connecting it to 5v and the ground ...does your LED turn on and off.

This proves if the circuit is picking up either the relay click or the spike from the relay.

Enrico has added a longer delay which could show if that is the problem.

You have what looks like a 220 ohm resistor across A0 to ground. You need something to hold it down, but I suspect a 100K will help give a much higher Analogue voltage which may help to stop the same voltage/spike from triggering it.

Generally it's best to not share the same earth/GND path with something that generates large spikes.

Motors/Relays and large loads should have the GND wire seperate from any analogue GND.

Lastly I presume it is a 5v relay.??

Mark

Hi Gabriel,

Here is a link to a MOSFET you can use:

http://www.newark.com/vishay-siliconix/irl510pbf/n-channel-mosfet-100v-5-6a-to/dp/63J7799

John

Hi Gabriel,

Here is a link to a MOSFET you can use:

http://www.newark.com/vishay-siliconix/irl510pbf/n-channel-mosfet-100v-5-6a-to/dp/63J7799

John