5V Output

[donaldhwong]

With an input Voltage at 12V from a battery, I needed a 5V out.  I looked at the schema of both your Moteino and MEGA, I don't think there is anyway I can get a pin with a 5V out.

Or is there?

If not, any simple suggestion that I can make it happen?

Thank you as always.

[Felix]

Have you looked at the spec at lowpowerlab.com/moteino ?
It's a pretty good place to study and get a lot of answers.
Moteinos are 3.3v devices. No 5v anywhere.

[donaldhwong]

Hi Felix,

Thank you for your quick reply.  Just trying to beat up a dead horse.

I know it is a dead end.  Just needed to make sure.

:-)
Donald

[TomWS]

Hi Felix,

Thank you for your quick reply.  Just trying to beat up a dead horse.

I know it is a dead end.  Just needed to make sure.

:-)
Donald

Donald,
you'll need a separate 5V regulator, powered from your 12V supply and, then, to interface between Moteino signal pins and your 5V device(s), you can use a circuit similar to what is used in a SparkFun level converter (unless you need high speed signalling - then you'll need a powered level translator):
https://www.sparkfun.com/products/12009

Just hit the schematic link for the implementation.
Tom

[donaldhwong]

Wow,  Tom comes to the rescue.  Thank you very much Tom.

I googled for such solution and found it costs me nothing, if I break open my old mobile phone car charger and use the circuit as is.

On a second note, I need to confirm with Felix that Moteino, R4 and MEGA can both work under a 12V supply??

Thank you again for your enthusiasm and support.

Donald

[Felix]

Again, help us help you. Please go to http://lowpowerlab.com/moteino/#specs where you will see the spec for the VIN pin max voltage.

[donaldhwong]

Hi Felix,

Thank you for pointing that out.  That's where I found the spec and my question is based on that. 

I just need your personal assurance that it will work at 12VDC without any issue.

Just being careful.

Thank you for your continual support.

Donald

[Felix]

Yes it will although it's very inefficient to feed that high of a differential into the Moteino voltage regulator. I usually recommend up to 9V but 12V will work.

[donaldhwong]

Hi Felix,

Thank you for your continuous support.

I truly appreciated.

Donald

[donaldhwong]

Hi Felix,

Hooked up one R4 Moteino with 12VDC power supply.  It fried.

Not sure your store warrant your product.  If you do not warrant product after our malpractice, I will order another one. No worry.

Thank you,
Donald

[Felix]

How did you hook it up?

[donaldhwong]

12 VDC through the USB.  Ah,  I just realized that I should not go through the USB.

I should have hooked it up to the VIN pin.

Sorry that I have troubled you.

Donald

[Felix]

Yeah ... external power has to be always applied through the VIN pin.