Go Down

Topic: Switching arduino and power off (Read 811 times) previous topic - next topic

lax123

Hi,

i created an arduino mega ambilight. Arduino is attached to USB and to 12V to power 4 Strips of RGB LEDs. It would be great if there was a way to switch the LEDs and the arduino off then just pulling out all plugs.
Is there a way?

The LEDs draw their power from Vin so i could put there a switch inbetween. But this leaves the arduino still on.

Another question: if i cut the power to the LEDs at Vin and the arduino is still connected to 12V and USB, would be still power drawn from the 12V power maybe by arduinos voltage regulator or something like that?

regards

johnwasser

I think you can cut the red (+5V) wire in the USB cable to force the Arduino to get power from the Vin pin, then put a switch on the 12V power.
Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

liudr


I think you can cut the red (+5V) wire in the USB cable to force the Arduino to get power from the Vin pin, then put a switch on the 12V power.


Neat!

lax123

#3
Feb 02, 2013, 04:16 pm Last Edit: Feb 02, 2013, 04:18 pm by lax123 Reason: 1
thanks for your reply.

Hmm i think cutting the USB and the 12V wire is a bit drastic. And i guess the optical result would be quite ugyl atleast for the usb cable.

So i guess there isnt another more simple way?


Could someone also maybe give me an answer to this?:
"Another question: if i cut the power to the LEDs at Vin and the arduino is still connected to 12V and USB, would be still power drawn from the 12V power maybe by arduinos voltage regulator or something like that?"

liudr

Yes Arduino still draws power from 12v supply. I think if you cut the mid section of the usb cable, and tucks that section away, no one may see the cut.

arduinoadrian

Is your Arduino working with the computer or it can be stand alone? If you just need the computer to program it and there is no further communication you don't need to keep the USB connected.
Perseverance is 90% of the solution. The remaining 10% is more perseverance.

lax123

the screen colour information is getting captured and sent to arduino so that it switches to the right ambilight colours. so the usb connection is very important :-)

arduinoadrian

Perseverance is 90% of the solution. The remaining 10% is more perseverance.

arduinoadrian

Maybe you can make your own box where you connect your USB on one side then the USB going to Ardunino on the other side (small cables though to keep the total distance withing range) and your "inbox" PCB will have a switch attached to interrupt the red wire connection John mentioned. You may have issues with noise though.
Perseverance is 90% of the solution. The remaining 10% is more perseverance.

PeterH


But this leaves the arduino still on.


That seems inconsequential compared to the amount of work needed to disconnect / disable the USB power.

Do you really care whether the Arduino is left running?
I only provide help via the forum - please do not contact me for private consultancy.

arduinoadrian

Peter:
I was about to post the same thing. I got mine permanently conected to the USB, I don't care.
Perseverance is 90% of the solution. The remaining 10% is more perseverance.

lax123

#11
Feb 02, 2013, 05:53 pm Last Edit: Feb 02, 2013, 05:55 pm by lax123 Reason: 1
Quote
Maybe you can make your own box ...

currently the setup has about 40 wires, to end this I am actually creating a pcb/shield in Eagle for arduino as several friends saw this ambilight and now want one too for watching movies and playing games.

So I guess I can implement a connector to feed the 12V directly into the shield instead of the arduino, as I then also can implement a power switch without having to cut the power wire.

Quote
...inconsequential compared to the amount of work needed to disconnect ...

Well I guess you are right and the arduino has to be permently powered up.

Maybe i can upload the files for the shield once its done if some other people are interested.
http://www.youtube.com/watch?v=4iTXP2d4V24&feature=youtu.be

thanks for the suggestions mates.


JimboZA

Why not supply the lights with their 12V directly from your 12v power source: if I understand correctly you're putting 12v into the Arduino (presumably at the barrel jack?) and just taking it straight out again from Vin...

(Or did I miss something? That's very likely... I almost knocked myself out on the brick lintel into my cellar earlier today, and literally saw those stars you see in the cartoons. You would never think I've lived in this house since 1988 and should know better by now?)
Roy from ITCrowd: Have you tried turning it off an on again?
I'm on LinkedIn: http://www.linkedin.com/in/jimbrownza

lax123

Hi,

isnt what ur saying and what i wrote practically the same?
Quote
So I guess I can implement a connector to feed the 12V directly into the shield instead of the arduino, as I then also can implement a power switch without having to cut the power wire.

JimboZA


Hi,

isnt what ur saying and what i wrote practically the same?
Quote
So I guess I can implement a connector to feed the 12V directly into the shield instead of the arduino, as I then also can implement a power switch without having to cut the power wire.



Yes, well I told you I might have missed something due to the smash on my head yesterday...
Roy from ITCrowd: Have you tried turning it off an on again?
I'm on LinkedIn: http://www.linkedin.com/in/jimbrownza

Go Up