Can anyone tell what's wrong with my circuit?

[UWouldKnow]

I am doing basic tutorials with an arduino but I can't seem to get this circuit to work. I hooked everything up and ran the given code but nothing happens. The relay is supposed to trigger the led's on and off but when I run the code the relay isn't even making any noise

 

[davenn]

am doing basic tutorials with an arduino but I can't seem to get this circuit to work. I hooked everything up and ran the given code but nothing happens. The relay is supposed to trigger the led's on and off but when I run the code the relay isn't even making any

most of your images are missing

show us your circuit diagram(s) for the circuit
also show the code for the micro

 

[mishima]

Have you tried running everything off battery power (or wall wart) instead of USB? Without seeing a schematic or relay number that would be my guess.

 

[sophiecentaur]

show us your circuit diagram(s) for the circuit

It concerns me that so many circuit experimenters seem to present their questions in the form of pictures of a breadboard layout. Am I so old fashioned in expecting a symbolic circuit diagram? I wouldn't expect someone with an arithmetic problem to have it presented in terms of piles of beans. I wonder if it's the general habit to work with wires and components, directly form the device spec sheet. A breadboard realisation of fast circuitry - or even slow analogue - can be full of parasitics.

 

[CWatters]

Have you got a multi-meter and done some basic checks? eg is power getting to all the places it should? Is there any evidence the code is running? eg is the pin that drives the relay changing? That check alone might narrow the problem down to one half of the circuit or the other.

 

[sophiecentaur]

I notice the OP has not replied to any of this. Perhaps he needs a chance to do some checking of his wiring and code.
We tend to forget how hard troubleshooting can be to the uninitiated (and even the initiated).

 

[UWouldKnow]

Have you tried running everything off battery power (or wall wart) instead of USB? Without seeing a schematic or relay number that would be my guess.

Thanks, I'll try that... I think that's what the issue is. What do you mean by wall wart? Is that something that converts the wall power into something suitible for an arduino

It concerns me that so many circuit experimenters seem to present their questions in the form of pictures of a breadboard layout. Am I so old fashioned in expecting a symbolic circuit diagram? I wouldn't expect someone with an arithmetic problem to have it presented in terms of piles of beans. I wonder if it's the general habit to work with wires and components, directly form the device spec sheet. A breadboard realisation of fast circuitry - or even slow analogue - can be full of parasitics.

Sorry I didn't mean to bother, I was just wondering if someone could see any obvious issues right off the bat. I was just curious as I am trying to learn and am in no need to try to get this circuit to work. The circuit diagram and code was made by a starter kit, so I am assuming that their circuit and code is correct. I should have been more clear and explained that

Have you got a multi-meter and done some basic checks? eg is power getting to all the places it should? Is there any evidence the code is running? eg is the pin that drives the relay changing? That check alone might narrow the problem down to one half of the circuit or the other.

Interesting, I would be glad to run some test with my multimeter but I have no idea what to check for. And you it receives the code but it is just not doing anything.

most of your images are missing

show us your circuit diagram(s) for the circuit
also show the code for the micro

The code and circuit diagram was created by a starter kit so I was assuming that it is correct, I could still add them to the chat if your interested though.

 

[davenn]

The code and circuit diagram was created by a starter kit so I was assuming that it is correct, I could still add them to the chat if your interested though.

we ALL want to see them so that we have a better understanding of what you are talking about

again ... please post them

 

[UWouldKnow]

 

[UWouldKnow]

we ALL want to see them so that we have a better understanding of what you are talking about

again ... please post them

Okay I just posted them

 

[sophiecentaur]

Troubleshooting:
The purpose of the following is not to make you feel bad - it's exactly what I (and the others here) would be checking from the very start)
Take nothing for granted about what you have done. Assembling circuits is an alien world for most people.
First of all, do you have your supply volts and ground actually arriving at your breadboard (both places) and processor?
Does the processor actually give you a different voltage on Pin 2 when it's supposed to? That test will determine if your code is ok. If that's a fail then look again at your code.
Are all the leads firmly in contact with the holes on the board?
Does the collector volts go 'down' when Pin 2 volts go 'up'?
I forgot - the most important is to check (twice) that the connections really are on the correct pins and not on a 'mirror image' in your head when you are looking at the thing upside down? (Happens every day!)
Is the transistor emitter actually connected to ground?
etc etc.
This is not a whole afternoon's work but something that need only take a couple of minutes and would be 'automatic'.
With luck, you may find one of the above tests 'fails' and you will have found your circuit fault.

 

[Asymptotic]

Are either of the LEDs lit?
If +5V and 0V (ground) are connected to the circuit then the LED on the N.C. relay pole ought to be on.

To isolate the transistor and Arduino output pin 2 from contention, temporarily disconnect the transistor collector wire, and jump it to ground. The relay coil should energize, switch the contacts, and the other LED ought to turn on.

If the relay doesn't switch, then a problem exists in this 'half' of the circuit.
If the relay operates, and the other LED turns on, then the problem is on the Arduino/transistor side.

 

[cnh1995]

You'll most likely be able to resolve the problem using the troubleshooting tips from Sophiecentaur and asymptotic.

My two cents: I believe it is also possible that your arduino board is sourcing too much current (coils+LEDs). That gives you an error message "problem uploading to board" when you try to run the code. What is the current rating of the relay coil? Try using a separate 5V supply to feed the coil.
Edit: I don't see a mention of such error message in your OP. Are you sure the code was uploaded successfully?

 

[Asymptotic]

Try using a separate 5V supply to feed the coil.

This is a great idea, and has shaken loose another possibility ... is the Arduino USB cable plugged directly into a computer USB port, or is it plugged into a USB hub? An unpowered USB hub doesn't have much current sourcing capacity, and more often than not, doesn't have the juice to power an external HDD.

 

[Guineafowl]

Is the diode the wrong way around?

EDIT: Scratch that - the diode IS the wrong way around, even in the breadboard diagram. Not your fault. The circuit diagram is correct. Give the person who drew the breadboard diagram an insulting slap across the face.

 

[davenn]

Is the diode the wrong way around?

EDIT: Scratch that - the diode IS the wrong way around, even in the breadboard diagram. Not your fault. The circuit diagram is correct. Give the person who drew the breadboard diagram an insulting slap across the face.

yup, good spotting

the flyback diode is reversed on the breadboard layout
result ... the relay won't operate

As @sophiecentaur said earlier, this is why we wanted the diagrams etc so we could check for errors

NOTE ... DONT DO Asymptotic's test UNTIL you have reversed the diode and checked operation, else you will just be shorting the 5V to ground via the poor diode and it probably won't survive that

To isolate the transistor and Arduino output pin 2 from contention, temporarily disconnect the transistor collector wire, and jump it to ground. The relay coil should energize, switch the contacts, and the other LED ought to turn on.

Dave